Coyote Gen3 rough idle at start then smooth

[JeffP]

I have a new Gen3 Coyote with a Lund tune. Anytime I start it (warm or cold) it idles very rough, almost stumbles, and it sounds like one side or the other of the engine isn't firing (The exhaust will be very quite on one side while the other is normal, and sometimes it'll even shift from one side to the other while its doing this). If I give it a little gas it'll stumble/hesitate a few times then it'll typically rev up and then runs smooth until the next time I start it. This entire process typically clears out within the first 20-30secs after starting the engine.

I've tried doing a little research and see some suggest the IAC valve or it could even be the coolant sensor but I'd expect that to only impact a cold engine.

Any ideas?

Oh - No codes.

[JeffP]

Digging deeper i guess these engines don't have an IAC so likely not that.

[edwardb]

My Gen 3, also with a Lund tune, has a slightly high RPM with first started and then seems to settle down plus make a somewhat different sound. It's like the cams phase once it's running for a bit. But that's just a guess. But certainly nothing like you describe. How long since you had the Lund tune? They've been great to me when I've gone back and ask questions or an adjustment after the tune was done for a while. Seems like this is something they could help with.

[Rsnake]

Mine does the same thing and Lund told me nothing they could do about it.
Something to do with the start up tables and they cannot change it. It doesn't do it all the time and doesn't matter if it's cold or hot. Would like to fix it but it runs like a scalded cat other than the start up issue or shall we say a scalded coyote

[Alan_C]

I know that this is about Lund tunes, but has anyone called and discussed with Ford Performance? I would want a second input on the subject as Lund seems to have the attitude you get what you get.
I am glad that I have a 2nd Gen Coyote and well respected tuners that can work on my car in shop.

[Rsnake]

I might try calling ford tomorrow as I never thought about going down that road.
Thank You

[michael everson]

I have experienced the same thing on a GEN 2 Actually sounds like one whole side of the engine isn't firing. I shut it off and restarted and it went away.
Mike

[JeffP]

My Gen 3, also with a Lund tune, has a slightly high RPM with first started and then seems to settle down plus make a somewhat different sound. It's like the cams phase once it's running for a bit. But that's just a guess. But certainly nothing like you describe. How long since you had the Lund tune? They've been great to me when I've gone back and ask questions or an adjustment after the tune was done for a while. Seems like this is something they could help with.

Its been a while so I'm sure i'm out of their warranty period but its been on my list to give them a call about it.


Mine does the same thing and Lund told me nothing they could do about it.
Something to do with the start up tables and they cannot change it. It doesn't do it all the time and doesn't matter if it's cold or hot. Would like to fix it but it runs like a scalded cat other than the start up issue or shall we say a scalded coyote

My neighbor is a former very high level engineer at Ford and I was talking to him yesterday about this. He said the same thing... Initial start its defaulting to standard tables and once the EGR warms up (20-30 secs) the computer is able to properly adjust and use data from the sensors instead of the tables. It would be unfortunate if the defaults can't be adjusted. I also thought the ECU was supposed to "remember" its adjustments - I'm fairly certain I have it wired to the always hot, so something I'll also check. It was certainly my intention in the design. So i'm assuming the ECU isn't having to relearn each time the power is off.

I'll try giving Ford a call too. Sounds like at least in the small sampling - I'm not alone and this may be more common than I thought.

[JeffP]

I believe this may be resolved - haven't had a chance to get out and drive it yet (raining) but starting it up in the garage it ran fine with no issues. I'm embarrassed to admit the o2 sensors were reversed. Probably all stems from doing my wiring on my kitchen table and this harness needed to have the driver side extended and not being in front of the engine LH/RH is very relative. Anyways, pulled the harness apart, extended the other one and swapped the cables hopefully is a relatively easy fix to this issue. Thanks to the guys at Lund who pointed me towards these after taking a look at a new log file.

[JohnK]

Nice. Glad to hear that it was something relatively easy and that they were able to spot that from a log file.

[JeffP]

Nice. Glad to hear that it was something relatively easy and that they were able to spot that from a log file.

Absolutely - Just got back from a test drive and its running great.

[facultyofmusic]

Whew thanks for the update Jeff! I've been worried that I'll see the same thing on my build.

[toadster]

interesting, got a first start on our Gen 3, and literally the driver side of the car doesn't seem to be firing...
Did a start this morning for about 30 seconds and the passenger side pipes were warm to the touch, but the driver side was just as cold as if it wasn't running... very perplexing!!

btw - I have a Lund tune coming, should have it monday so that may help (hopefully!)


https://youtu.be/vaNWnxIe0ZI

here are the codes, not surprising because I removed the CMCV valves (of which Lund is tuning those out anyways)

183314 183315

[edwardb]

Yeah, those are the codes if your CMCV valves are removed or not plumbed properly. The difference they make to how the engine runs are pretty subtle, to be honest. Tuning them out for our purposes is fine. Really doubt they would have anything to do with cylinders not firing. I'm assuming you have lockouts installed so they're fixed open? Hopefully Lund will help you out with this. You're doing a Lund tune at the go-kart stage? I expect you know their tune requires you to do extensive driving? They provide the profiles they want you to follow while running the data log. Up to and including wide open throttle hits once the tune gets close. I never started the tune processes on mine until they were complete, legal, and I could drive extensively (and legally). BTW, another first start with open headers. Don't see ear protection. That's hard on your equipment. :rolleyes:

[Railroad]

Lund will get you a tune to get started and then data log after street ready.

[edwardb]

Lund will get you a tune to get started and then data log after street ready.

Haven't heard that before. The several times I've used Lund I was under the impression the coverage was for three months. That's great if they would work with you that way. Especially if it doesn't start or run OK from the beginning. My Gen 3 started and ran on the base Ford tune. But was undriveable once street ready. They fixed me up.

[32J]

Me three! I have about another 900 km to go on my break-in before I approach Lund for a tune on my Gen 3. Glad to hear it was anything major.

[toadster]

Yeah, those are the codes if your CMCV valves are removed or not plumbed properly. The difference they make to how the engine runs are pretty subtle, to be honest. Tuning them out for our purposes is fine. Really doubt they would have anything to do with cylinders not firing. I'm assuming you have lockouts installed so they're fixed open? Hopefully Lund will help you out with this. You're doing a Lund tune at the go-kart stage? I expect you know their tune requires you to do extensive driving? They provide the profiles they want you to follow while running the data log. Up to and including wide open throttle hits once the tune gets close. I never started the tune processes on mine until they were complete, legal, and I could drive extensively (and legally). BTW, another first start with open headers. Don't see ear protection. That's hard on your equipment. :rolleyes:

hopefully tomorrow we will see if the car runs better after the initial tune, not worried much about the codes and yes the CMCV are locked open
I gave them all the configs of the engine and they are aligning a base tune
I cranked up the PSI on the Aeromotive FPR to around 64 just from the battery kicking in -we've noticed the pressure rises a little when the car starts so will be watching that as well

since the car was really only firing on the passenger side, it's about 1/2 volume, plus the catalytic converters seem to muffle a bit as well :)


Lund will get you a tune to get started and then data log after street ready.

yes, that's the plan :)


Haven't heard that before. The several times I've used Lund I was under the impression the coverage was for three months. That's great if they would work with you that way. Especially if it doesn't start or run OK from the beginning. My Gen 3 started and ran on the base Ford tune. But was undriveable once street ready. They fixed me up.

I get 6 months of free support - maybe they've changed their setup :)

FREE - 6 Months Support (Non-Recurring)
SKU: 6_months_free_support

[JohnK]

My gen2 coyote didn't run particularly well initially. I reached out to Lund and they explained that if I purchased a tune they could send me a file to upload based on previous customers' cars with similar configurations until I was able to get up and running and datalog my own engine, within a 6 month window. If I didn't get to the point that I could do a custom tune on my own engine within the 6 month window I could extend it for another 6 months for an additional fee (which is what I plan to do.). The file they sent me that is based on other customers cars was a significant improvement over the stock gen2 tune.

[toadster]

The wait begins :) patience counts right now!




Thank you! There is no need to reply to this current ticket right yet. This ticket will now be written up and will go into the tuning queue. If you reply it pops your ticket out of the queue order.
ETA varies. Usually its the next business day unless we are on a long weekend, have high volume, or if people are out.
Once we send the tune we will be emailing you to notify that it is ready and with instructions.

[toadster]

got the tune installed last night, started right up - idles better as well
driver side pipes feel cooler than the passenger side though - very odd

gas tip-in causes a stumble, and when revving the driver side has some pops - will have to log some runtime and get back to them, no CEL this time :)

[JeffP]

I did my logging drives yesterday, and trying to get the final WOT from 2500-7500 rpm is proving to be a challenge. I certainly feel like i've got the pedal on the floor but its not even close. I've hit the rev limiter and still haven't had the pedal past 70% getting there. trying to find a safe place to do it even just once is challenging.

[Jeff Kleiner]

got the tune installed last night, started right up - idles better as well
driver side pipes feel cooler than the passenger side though - very odd

gas tip-in causes a stumble, and when revving the driver side has some pops - will have to log some runtime and get back to them, no CEL this time :)

Todd,
Pick up an inexpensive infrared thermometer (about 30 bucks at HF, Lowe’s, etc). You’ll be able to read each pipe individually which is great for diagnostics. Despite what my wife says you can also point it at your forehead to see if you have a fever :)

Jeff

[toadster]

Todd,
Pick up an inexpensive infrared thermometer (about 30 bucks at HF, Lowe’s, etc). You’ll be able to read each pipe individually which is great for diagnostics. Despite what my wife says you can also point it at your forehead to see if you have a fever :)

Jeff

ah yes! I do have one of those! will test again today :)

so strange, I've never really heard of 'one bank' not firing properly, but what do I know, this is my first crate motor startup :)

[toadster]

183605

just as suspected... #3 and #4 cylinders are hottest, #2 and #1 are a little lower, catalytic collector is warmer (as expected)

183606 183608

#5, 6, 7, 8 are all much cooler, all about the same temps, its maybe 15F hotter than ambient temps today (83F at the time of temp taking)

183607 183609

[Jeff Kleiner]

15 degrees over ambient is just the heat of compression. They aren’t firing.

Jeff

[JeffP]

183605

just as suspected... #3 and #4 cylinders are hottest, #2 and #1 are a little lower, catalytic collector is warmer (as expected)

183606 183608

#5, 6, 7, 8 are all much cooler, all about the same temps, its maybe 15F hotter than ambient temps today (83F at the time of temp taking)

183607 183609

Did you do the wire splice on the coil over for the RPM sensor? Any chance that didn't get plugged back in or messed up?

[toadster]

15 degrees over ambient is just the heat of compression. They aren’t firing.

Jeff

yep seems apparent now - so odd!!


Did you do the wire splice on the coil over for the RPM sensor? Any chance that didn't get plugged back in or messed up?

redid the purple wire splice on #4 last night, we used a wire tap previously, need to reset the tachometer setting to .5 to get readings but the Lund tuning software sees RPMs no issue

I sent a log into Lund to see if they can see anything else
only thing I can think of is maybe a bad solder joint while extending the O2 sensor wires - not the O2 bung wires, but the extensions to reach over to the driver side...
will see what they say tomorrow :)

[JeffP]

redid the purple wire splice on #4 last night, we used a wire tap previously, need to reset the tachometer setting to .5 to get readings but the Lund tuning software sees RPMs no issue

I sent a log into Lund to see if they can see anything else
only thing I can think of is maybe a bad solder joint while extending the O2 sensor wires - not the O2 bung wires, but the extensions to reach over to the driver side...
will see what they say tomorrow :)

You can download LiveLink software here for free: https://derivesystems.helpjuice.com/136470-info/346005-downloads and load your csv log into it. Maybe see if anything looks odd on the STFT11 and STFT21?

I don't know the first thing about tuning, but it was pretty cool to dig into the logs a little and see whats going on.

[toadster]

yes, I do see a big imbalance on startup - but then they both zero out... hopefully they'll get back to me with some ideas


183623

[toadster]

Lund replied that the O2 is really lean, but they didn't specify... I looked at the log, seems like bank 2 (which I believe is driver side) is the culprit - will have to pull the O2 wiring and check the solder joints

183628

[Rsnake]

Mine does this crazy stuff on startup for about 10-15 seconds then it goes away. Have been told by Lund that they cannot control startup parameters and once the O2 sensor warms a little the Lund tune takes over.

[edwardb]

It's a little bit of a mystery to me that an O2 sensor issue would take out the whole bank. I can see the A-F ratio getting messed up, running poorly, MIL on with indicating codes, etc. But completely shut off? Honestly though I don't know. It wouldn't be hard to swap O2 sensors side-to-side and see if the problem moves. After you confirm the wiring is OK.

[Jeff Kleiner]

It's a little bit of a mystery to me that an O2 sensor issue would take out the whole bank. I can see the A-F ratio getting messed up, running poorly, MIL on with indicating codes, etc. But completely shut off? Honestly though I don't know. It wouldn't be hard to swap O2 sensors side-to-side and see if the problem moves. After you confirm the wiring is OK.

I think we’re seeing a “which came first, the chicken or the egg” scenario here. The sensor isn’t shutting down the bank of cylinders but rather the bank of dead cylinders is causing the sensor to be out of range. As for why one side of the engine is dead??? I don’t have a guess at this time.

Jeff

[toadster]

swapped O2 sensors side to side, still cold on driver side, and hot on passenger...

going to trace the wires that we extended to ensure we have signal... other than that i'm a bit stumped!
I wouldn't think a bad o2 signal would stop one side from firing...

[JohnK]

I think checking the solder connections is the right place to look. Whenever I'm having issues I always look at where I may have introduced failure points through human error. Hopefully it's something simple.

[JeffP]

yep seems apparent now - so odd!!



redid the purple wire splice on #4 last night, we used a wire tap previously, need to reset the tachometer setting to .5 to get readings but the Lund tuning software sees RPMs no issue

I sent a log into Lund to see if they can see anything else
only thing I can think of is maybe a bad solder joint while extending the O2 sensor wires - not the O2 bung wires, but the extensions to reach over to the driver side...
will see what they say tomorrow :)

Tapped purple wire - The purple wire from the harness into the non-purple wire on the coil over plug correct? I think the purple wire on the coil over is the common across all of them and each unique coil over has a different color signal wire. If you tapped purple to purple that may be messing up that side. You said you had to reset the gauge but didn't mention if it was working... Lund seeing RPM's in the log has nothing to do with this tap.

[toadster]

Tapped purple wire - The purple wire from the harness into the non-purple wire on the coil over plug correct? I think the purple wire on the coil over is the common across all of them and each unique coil over has a different color signal wire. If you tapped purple to purple that may be messing up that side. You said you had to reset the gauge but didn't mention if it was working... Lund seeing RPM's in the log has nothing to do with this tap.

correct purple to non-purple, initially we used a posi-tap and thought we maybe weren't getting a good connect - cylinder #4 is really tight against the footbox so we soldered purple to the non-purple as prescribed

as for the tach reset, I may have not saved the setting properly, assuming the memory for the tach survives battery disconnects - if not, then yes, I'll have to reset each time I would disconnect the battery I assume

[edwardb]

as for the tach reset, I may have not saved the setting properly, assuming the memory for the tach survives battery disconnects - if not, then yes, I'll have to reset each time I would disconnect the battery I assume

Speedhut gauge calibration settings don't get erased when the battery is disconnected. They're in non-volatile memory. Normally once and done.

[toadster]

Speedhut gauge calibration settings don't get erased when the battery is disconnected. They're in non-volatile memory. Normally once and done.

good to know, still need to troubleshoot the gauge, I did confirm it's set for the .5PPR when I push the menu button - still not showing revs when the car starts

sent in another log to LUND, assuming they'll just say it's O2 lean again

called Ford Performance, they suggested checking C146 pin #1 - and we're getting 12V which powers the injector/spark rails

they also suggested checking ground and should get .1Ohm or less

we're getting .1-.5 ohms between the engine ground on the passenger engine mount and a spot on the frame
also between the battery and where it's grounded it's showing .3-.5 ohms which seems off as well

pulled a plug from bank #2 (actually plug #6) after the logging, definitely not firing

183669

[toadster]

got a PO356 code back from Lund, I somehow missed this but it's an ignition coil circuit code for cylinder number 6. Of which is on bank 2

A vehicle’s PCM could log a P0356 code for a handful of reasons:


The (COP) could simply be faulty
Coil #6 could have a loose connection
Coil #6’s connector locks could be broken
The COP driver circuit is open
The COP driver circuit has a short to voltage or is ground

[Nigel Allen]

That plug insulator looks awfully carbonised. Swap your plugs to opposite banks and see if the fault follows.

Nige

[toadster]

That plug insulator looks awfully carbonised. Swap your plugs to opposite banks and see if the fault follows.

Nige

pulled Plug #1 from bank #1 looks dark like #6 but less oily for sure, we're checking the main grounds and swapping coil pack #6 and #1 to see if there's a bad coil

183700

[Nigel Allen]

Measuring resistance to look for bad grounds in vehicles is not easy and often leads to erroneous measurements which will take you down rabbit holes. A simpler and more solid way is to measure volt drop when a load is applied. Let's use the starter motor as the load.
With your meter set to DC volts, manual range. Apply one meter probe to your negative battery terminal and the other to your engine block. Observe meter reading whilst cranking, it should be less than 1volt. Any higher than that, and you have excessive resistance in your ground path.
Now repeat for positive path. Apply one meter probe to the positive battery terminal and other to starter positive terminal. Crank and measure volt drop on meter whilst cranking. Also should be less than a volt.
Make sure you measure to the terminals, that way you are also including the final connections in your measurements.

Let me know if you need further explanation or interpretation of measurement.

Best of Aussie luck to you. The quality of the coyote engine makes me feel that you will get there sooner than later.

As an aside, I found Lund a little blunt to deal with. Maybe the guy I dealt with was jaded, but I paid over a $1,000 Australian for a support guy that told me I was a wimp for not wanting to take car full load to 6500rpm. We had an unseasonably wet and cold winter and I was having traction issues at 60mph. I got there in the end using a dyno. Also he struggled with our fuel ratings here and in the end put what seems a very doughy tune in. It runs great otherwise. My takeaway is that Lund feel that they are the top dog. My advice is to keep the pressure on if they don't support you well.

Next time, I will use my local dyno. Those guys were great and super keen to help. Like I said, maybe I got the wrong guy, so hopefully your experience and others will be better.

Cheers,

Nige

PS: that spark plug looks bad enough not to fire on a cold engine.

[toadster]

swapped coils around, I cleaned the whole driver side bank of plugs - surprisingly serviceable (albeit no body on) - still getting the plug#6 misfire

Lund is suggesting maybe the harness is bad... I'd much rather replace a plug first, but I wouldn't think and engine running less than 15 minutes total would foul a plug - maybe just a bad plug out of the box?
we did replaced the power wire to the driver side to ensure the wire is the correct size, we had ~14ga wire in line and swapped out to 16ga which looks to match the rest in the loom.

does anyone have the pinout/schematic of the UEGO sensor wires? thinking maybe we have a bad solder joint in our extensions but would like to understand what each wire is first to tackle

[JeffP]

swapped coils around, I cleaned the whole driver side bank of plugs - surprisingly serviceable (albeit no body on) - still getting the plug#6 misfire

Lund is suggesting maybe the harness is bad... I'd much rather replace a plug first, but I wouldn't think and engine running less than 15 minutes total would foul a plug - maybe just a bad plug out of the box?
we did replaced the power wire to the driver side to ensure the wire is the correct size, we had ~14ga wire in line and swapped out to 16ga which looks to match the rest in the loom.

does anyone have the pinout/schematic of the UEGO sensor wires? thinking maybe we have a bad solder joint in our extensions but would like to understand what each wire is first to tackle

https://performanceparts.ford.com/download/instructionsheets/FORDINSTSHTM-6017-M50B.PDF

Scroll to bottom and it has pinout for those connectors.

[Nigel Allen]

Change the plugs. A fouled plug on #6 might be causing the problem. The plugs look bad and may have been fouled excessively when running with exhaust sensing reversed.
Although my coyote is gen1, I found myself with rough running after multiple cold starts when testing. This was before and after Lund tune.

[Nigel Allen]

On the gen1 loom there is an inline fuse that feeds the exhaust sensors (heaters, maybe?) Not sure if that is case for yours... Might be worth following up.

Best of luck,

Nige

[JeffP]

Change the plugs. A fouled plug on #6 might be causing the problem. The plugs look bad and may have been fouled excessively when running with exhaust sensing reversed.
Although my coyote is gen1, I found myself with rough running after multiple cold starts when testing. This was before and after Lund tune.

I don't think he had his sensors reversed - I get to take credit for that one!

[toadster]

Change the plugs. A fouled plug on #6 might be causing the problem. The plugs look bad and may have been fouled excessively when running with exhaust sensing reversed.
Although my coyote is gen1, I found myself with rough running after multiple cold starts when testing. This was before and after Lund tune.


On the gen1 loom there is an inline fuse that feeds the exhaust sensors (heaters, maybe?) Not sure if that is case for yours... Might be worth following up.

Best of luck,

Nige

we checked all fuses, nothing was bad, but we did check - thank you :)


https://performanceparts.ford.com/download/instructionsheets/FORDINSTSHTM-6017-M50B.PDF

Scroll to bottom and it has pinout for those connectors.

perfect - this will help with troubleshooting, the Bank2 (driver) O2 is pegged at 1.5, super rich, we're thinking it may be wire extensions so we'll redo these -
we swapped o2 sensors side to side, and the problem stayed on the driver side, I cleaned all 4 plugs on the driver side, wire brush and WD-40 (believe it or not) but they may be too cruddy...

the numbers on the right (below) came from Ford for the pinout of the ECU connectors

183895


I don't think he had his sensors reversed - I get to take credit for that one!

yep! we even chatted with Ford Performance to verify the color of the wires per bank and we have the correct wires on the correct side as we had removed the labels marking the bank1 and bank2 sides - so we're good there

since the passenger side is so short, we shortened that run to not have the wires loop 1/2 way across the engine and come back - so it's a short extension to the O2 connector, the red wire was extended from the C146 plug over to the driver side, about 3.5-4 feet, and the other 4 lines were extended about 15 inches each.

we tested continuity and all 5 wires are fine, I'm wondering if the solder joints are creating resistance that is not reaching the ECU and thereby pegging the O2 sensor to flood the driver side with fuel

[edwardb]

...I'm wondering if the solder joints are creating resistance that is not reaching the ECU and thereby pegging the O2 sensor to flood the driver side with fuel

The Ford Performance directions say to not modify the O2 sensor harnesses. But with the standard lengths delivered on both Gen 2 and Gen 2, you are left with either modifying them or adding purchased extensions. I've cut and soldered the O2 harness wires on both of my Coyote builds with no issues whatsoever. Note I said harness and not the wires in the pigtail between the sensor and the plug. That has special insulation and wire that isn't friendly to work with (ask me how I know) and should be left alone. As long as you have good connections on the splices you did there shouldn't be an issue. It's just standard hook-up wire and the small amount of solder shouldn't matter. It hasn't for me.

I agree with the post Jeff Kleiner made earlier. It's likely your O2 sensors are reacting to another problem. As opposed to them being the problem itself. Especially since you aren't getting specific O2 sensor DTC's. They could fail completely or even be removed and the engine should still run on all cylinders. Albeit poorly and maybe even go into limp mode. Same with fouled plugs. The Coyote (like all modern engines) has a hot ignition system that can fire through most plug situations. The maintenance cycle on them is 100K miles. Again, the fouled plug(s) IMO is a symptom of another issue but not the issue itself.

Something else is wrong IMO. Has Ford Performance suggested the possibility of re-flashing your PCM? More than one problem has been solved by that step. That used to be a pretty standard go-to when everything else seemed OK. Has happened to me once. It would wipe out your Lund tune. But just re-load it again.

[JeffP]

Agree with Paul and Jeff on this one that the o2 is more of a symptom. Given I had mine reversed for 1000mi and (at least after initial startup) the car ran perfectly.

[toadster]

The Ford Performance directions say to not modify the O2 sensor harnesses. But with the standard lengths delivered on both Gen 2 and Gen 2, you are left with either modifying them or adding purchased extensions. I've cut and soldered the O2 harness wires on both of my Coyote builds with no issues whatsoever. Note I said harness and not the wires in the pigtail between the sensor and the plug. That has special insulation and wire that isn't friendly to work with (ask me how I know) and should be left alone. As long as you have good connections on the splices you did there shouldn't be an issue. It's just standard hook-up wire and the small amount of solder shouldn't matter. It hasn't for me.

I agree with the post Jeff Kleiner made earlier. It's likely your O2 sensors are reacting to another problem. As opposed to them being the problem itself. Especially since you aren't getting specific O2 sensor DTC's. They could fail completely or even be removed and the engine should still run on all cylinders. Albeit poorly and maybe even go into limp mode. Same with fouled plugs. The Coyote (like all modern engines) has a hot ignition system that can fire through most plug situations. The maintenance cycle on them is 100K miles. Again, the fouled plug(s) IMO is a symptom of another issue but not the issue itself.

Something else is wrong IMO. Has Ford Performance suggested the possibility of re-flashing your PCM? More than one problem has been solved by that step. That used to be a pretty standard go-to when everything else seemed OK. Has happened to me once. It would wipe out your Lund tune. But just re-load it again.


Agree with Paul and Jeff on this one that the o2 is more of a symptom. Given I had mine reversed for 1000mi and (at least after initial startup) the car ran perfectly.


agreed, since we have continuity in wires and driver side is always pegged rich, I'm talking to Ford to get the PCM reflashed

ordered 8 new plugs as well, relatively cheap in the grand scheme of things... Ford was pretty stumped as to why Bank2 wouldn't fire properly

the only things I've found online in regard to this issue is a plugged catalytic converter, of which I have them in the headers, but we're feeling airflow, just not hot like the passenger side
knowing my luck somehow JetHot melted or damaged the media when coating these headers (and/or) the rich fuel mixture could have done it as well...

pretty frustrating as we've never even run this engine hot enough to get the fans to kick in - we've only achieved about 126F on the coyote temp meter

thanks all for your inputs, what seemed to be a simple crate motor setup has become quite frustrating...

[Railroad]

Would a noid light help in seeing what is doing what?

[toadster]

Would a noid light help in seeing what is doing what?

I rented one yesterday, haven't had a chance to test it yet

[Nigel Allen]

What happens if you unplug the driver side sensor, then start the engine?
Could it be that because the sensor is reading rich, that fuel is not being injected on that bank?

Apologies if you have already tried this.

Cheers, Nige

[toadster]

What happens if you unplug the driver side sensor, then start the engine?
Could it be that because the sensor is reading rich, that fuel is not being injected on that bank?

Apologies if you have already tried this.

Cheers, Nige

just tried this - unplugged the O2 sensor on the driver side, same symptoms as with it plugged in
even swapped the #6 and #1 plugs to see if it was a fouled plug, same issues...

I tried the noid lights but couldnt' get any of the adapters to fit the coyote plug wire feeds, may try rigging up some aligator clips and pins to try to hook them up but none were a direct fit

[Railroad]

They make a hand held noid light. It looks like a screw driver with a paddle on the end. You can hold it near the wire or device you are checking. No connecting or disconnecting.

[toadster]

They make a hand held noid light. It looks like a screw driver with a paddle on the end. You can hold it near the wire or device you are checking. No connecting or disconnecting.

I'll have to check those out, found them in some searches too - not too pricey...
something dawned on me last night

I removed my CMCVs from the back of the Coyote, and there are 3 connectors inline on the way to bank 2 behind the back of the engine
I have a query out to Ford on this as well, but do these connections help to ground Bank 2?

184025 184026

if I created a ground gap, then it would affect all spark on the driver side... of course, I think I tossed the whole setup so I'd need a new solenoid ~$25

[toadster]

spent the better part of today testing continuity and resistance on about 40 ECU wires - the harness looks to be working, tested connectivity to each coil pack and ground, and each injector and ground

can't test the coil packs - the online stuff I've seen is for all older 4.6/5.4 engines

I have one of the flyswatter noid lights coming tomorrow to verify spark activity -most likely will ship the ECU in monday to ford

[Indy Shu]

If you want to check a coil, just pull it out and put a spare spark plug in it. Start the engine and see if it is firing. Takes about 30 seconds. I found I had a dead coil this way. Ford sent me a replacement.

[Jeff Kleiner]

Todd,
Noid light will only tell you that you’re sending an electrical signal to a coil but won’t tell you that it’s actually working. Do what John said above and you’ll have your answer.

Jeff

[toadster]

If you want to check a coil, just pull it out and put a spare spark plug in it. Start the engine and see if it is firing. Takes about 30 seconds. I found I had a dead coil this way. Ford sent me a replacement.

yep going to do this today as well :)

i'm getting pretty good with this 8mm socket (haha)

[toadster]

tested the noid light, all COP firing, cylinder #4 seemed to be double speed firing
also tested each coil with an arc test, all 8 are producing spark as well - shipped off the ECU, nothing else that we can possibly do

[toadster]

got the ECU back from Ford.. slightly different response

from LUND
"It's still showing the same problem. Ignition coil F circuit, and AFR on bank 2 still max lean.
What's really weird though is the fuel trim for that bank isn't reflecting the issue.
The trim looks fine. If it was really that lean as AFR is showing I'd expect the fuel trim to be trending in a fashion to correct for it."

my confusion:


we tested all 8 coils, moved them between cylinders, also move sparkplugs between cylinders - but Ignition coil F circuit is still not working properly (this is cylinder #6)
we also swapped O2 sensors side to side, and the problem is lambda is still pegged on bank2 which I believe may be a wiring issue? although we tested continuity and resistance


Here's the info from my log (HP Tuners OBD2), this is on the stock ECU code that was re-programmed, nothing else modified
The P2008, P2017, P2022 are all expected as I removed the IMRC valves from the rear of the intake (the tuner can remove those issues)
P0365 is the one that keeps showing up which is cylinder #6
I don't remember seeing P0124 before, but is shown in this log this is a generic OBD-II code that indicates the TPS sensor circuit A output voltage goes below or above the sensor's expected range

Protocol Info: J1962: CAN, 500 kb/s

ECM: 7E8, CAN, ECM -EngineControl - TC-298, 2018+ Ford
VIN: ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ
User OS: FRPP9
Calibration IDs: ÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃ
Calibration VNs: 79FD439B
Basic PIDs: 44
Trouble Codes:
P2008 - Intake Manifold Runner Control Circuit/Open Bank 1 (Pending)
P2017 - Intake Manifold Runner Position Sensor/Switch Circuit High Bank 1 (Pending)
P2022 - Intake Manifold Runner Position Sensor/Switch Circuit High Bank 2 (Pending)
P0356 - Ignition Coil F Primary/Secondary Circuit (Permanent)
P0124 - Throttle/Pedal Position Sensor A Intermittent (Permanent)
Controller Type ID By User OS: 12018


a bit stumped...


any ideas?

Ford is escalating to engineering...

[edwardb]

P0124 in my experience with a new engine is a false positive. Which could be the same in your case with a newly flashed ECU. Clear it and I bet it doesn't come back. After all you've been through and still the problem isn't isolated, my vote is something wrong with your harness. Another builder on here had issues he couldn't resolve with a Gen 2. After exhausting all the options, Ford Performance supplied a new harness and all good. Obviously a pain to tear out the old and replace, but that's my guess. Hopefully Ford is standing behind this because clearly it's not working as it's supposed to and seemingly there are no user errors. I feel for you. Took my Gen 3 powered Coupe for a 50 mile cruise today. Runs so perfect. Hang in there. Yours will be like that.

[toadster]

P0124 in my experience with a new engine is a false positive. Which could be the same in your case with a newly flashed ECU. Clear it and I bet it doesn't come back. After all you've been through and still the problem isn't isolated, my vote is something wrong with your harness. Another builder on here had issues he couldn't resolve with a Gen 2. After exhausting all the options, Ford Performance supplied a new harness and all good. Obviously a pain to tear out the old and replace, but that's my guess. Hopefully Ford is standing behind this because clearly it's not working as it's supposed to and seemingly there are no user errors. I feel for you. Took my Gen 3 powered Coupe for a 50 mile cruise today. Runs so perfect. Hang in there. Yours will be like that.

thanks Paul - this build has been a challenge for sure, but we thought the crate motor would have been 'plug-and-play' like many others, but this gremlin sure has tested our patience...
when Ford says - I've never heard of this, that's not reassuring...

we keep pluggin away...

[JeffP]

thanks Paul - this build has been a challenge for sure, but we thought the crate motor would have been 'plug-and-play' like many others, but this gremlin sure has tested our patience...
when Ford says - I've never heard of this, that's not reassuring...

we keep pluggin away...

Any update? Curious on the outcome of this.

[toadster]

Ford was out Friday and today for the holiday, will calll again tomorrow…

[toadster]

the main guy "Ken" at FP wasn't available today, the other tech I talked with said that extending the O2 harness would most likely screw up the O2 readings...

I did do a test over the weekend and moved the O2 harness from bank2 over to bank1 (obviously the bank1 leg is too short to extend to bank2 so I ran bank 2 open)
Lund confirmed that the problem followed the harness, O2 shows pegged lean on bank1 when I move the harness over

not sure if we did something different, but we soldered in similar sized wire when we extended the harness - about 16 inches per wire, the red wire has a full run from the split in the harness all the way to the sensor.

I believe I may need another CM-14A006-MTRANS harness which is the O2 extension 90-pin plug, waiting to hear back from Ford

I can't find this by itself on Ford Performance's catalog, so may be a special order
185203

at this point I may get a new CM-14A006-MTRANS harness and buy some extenders instead of soldering, there's no way the stock harness can reach both ends of the O2 plugs in this setup
if someone has been able to get the wires to reach without extending, I'm all ears...

[JohnK]

Hey Todd - so sorry to hear that this has been such a hassle for you. Just thought I'd share my experience in case it's helpful for you. On my first set of headers I was able to connect both O2 sensors without extending the harness (barely), but when I switched to the Gas-N headers the PS was just barely too short. Gas-N provide 12" extenders with the headers, so I used one on the PS side and it works perfectly. Hopefully using the extender vs. the soldered extension solves your problem.

[edwardb]

the main guy "Ken" at FP wasn't available today, the other tech I talked with said that extending the O2 harness would most likely screw up the O2 readings...

I did do a test over the weekend and moved the O2 harness from bank2 over to bank1 (obviously the bank1 leg is too short to extend to bank2 so I ran bank 2 open)
Lund confirmed that the problem followed the harness, O2 shows pegged lean on bank1 when I move the harness over

not sure if we did something different, but we soldered in similar sized wire when we extended the harness - about 16 inches per wire, the red wire has a full run from the split in the harness all the way to the sensor.

I believe I may need another CM-14A006-MTRANS harness which is the O2 extension 90-pin plug, waiting to hear back from Ford

I can't find this by itself on Ford Performance's catalog, so may be a special order
185203

at this point I may get a new CM-14A006-MTRANS harness and buy some extenders instead of soldering, there's no way the stock harness can reach both ends of the O2 plugs in this setup
if someone has been able to get the wires to reach without extending, I'm all ears...

A bunch of us, me included, have shortened and lengthened the O2 harness wires with zero issues. I've done it on both the Gen 2 and Gen 3. I know the Ford instructions say not to. But it's plain old automotive hook-up wire up the the O2 sensor plugs. I have no idea why a properly spliced wire (several ways to do it) would be a problem. But apparently you found out. Factory made extensions are another option and some go that way. Casper's Electronics is a source I've seen mentioned. Based on a quick search, BBK is another with a number of choices. Looks like you'll have to start with a new harness leg though if testing confirms the one(s) you have can duplicate the problem.

[toadster]

Ford got back to me and is talking with their electrical team to see if they can get me a new pigtail for the O2 sensors
it's a waiting game at this point, the tech lead won't be back until at least 6/5

[toadster]

well, I was travelling all week - Ford dropped a new O2 harness in the mail, should be here next Thursday... oh the waiting!

I also picked up a 24" O2 extension (https://www.lethalperformance.com/lethal-performance-109677-24-2018-mustang-gt-02-extension-harness-24-5-pin-1-piece.html) from Lethal Performance which may remove the need to solder any extensions

[toadster]

got the new o2 harness today from Ford, only peeled back the tape enough to get the o2 wires to reach, i added a 24" o2 extender which helped with the width - still will have to modify the red wires somehow to clean up the wiring it's just way too short side to side

same issue, pegged lean on the driver side

we even swapped cables side to side and the problem still exists on the driver side bank

literally driving me crazy at this point

1. ECU was reflashed by ford
2. new o2 pigtail didn't resolve the issue

any coyote gurus with ideas?

taking the car to the painter tomorrow to get the rough in done, and I'll have some time to wait on paint but need to get this resolved!

[Nigel Allen]

Measure the O2 sensor heater wires to verify voltage at the heater elements.

[Alan_C]

Good call. I had this happen on my build where a pin in one of the O2 extender connectors was not seated and pushed back to where contact for the heater circuit was not working. So one bank was not running properly and fortunately the shop I took the car to diagnosed the issue in about an hour. I had replaced that O2 sensor twice before figuring out the issue.

[Nigel Allen]

Flashing the ECU will not fix a hardware issue, if there is one within the ECU. Hopefully they operationally tested the ECU to prove all circuits operate correctly. It could be that the ECU has a pre existing hardware fault.

Is there anyone nearby that you can swap an ECU with to test?

Sorry to see you having so much pain with this issue.

Wishing you the best of luck,

Nige

[toadster]

no clue if they tested functionality of the ECU, you'd think that would be standard procedure, but I'm assuming...

Lund is recommending trying a new o2 sensor, so $80 later and waiting for it to arrive- although the car is at the painter getting pre-fit prior to paint - so I have a week or so to wait...

no nearby ECUs that aren't already mounted - would be a PITA to pull one just for testing

[toadster]

just to give an update on this

I got a new O2 sensor, but doubtful that it will be useful - may just return it

the PO365 code it lends itself to a circuit issue, so Ford gave me some more testing to do; it's pretty rigorous but it's testing for voltage and resistance at the coil connector to the ECU pinout
essentially finding a short either in the engine harness, the control pack harness, or the ECU - definitely not in the usual installation manual :(

hopefully i'll get up to Ken's and can do some testing to get parts shipped out when I get the chassis back...

[toadster]

3+ months later, still no progress... can't get Ford to call me back (grrrr) - won't reply to emails either...

who can I escalate this to?

[Railroad]

With nothing to lose, you might consider throwing this problem out to some outside sites.
I would consider this site, you can refer back to you thread here.
https://svtperformance.com/
IMO this has to be harness or ECU. I would think Ford would cover your cost, after you buy the second of either.
Ford did send out a second harness to a builder here in my state, curing the problem.
Good luck,

[toadster]

agreed, what we're trying to determine is which harness... We had quite a test requested from Ford, the only test that 'failed' was JF8 Check the Suspect Coil Driver Circuit for a Short to Ground

https://docs.google.com/spreadsheets/d/1Q4LdzP7NbVuKLAxFtXjAFzTOSFj7Ix_T3zYP6Gl1l7o/edit?usp=sharing

all 8 coils showed O.L. on two different multimeters with this test, which may suggest a common ground break, but not sure if it's the PCM harness or the actual harness on the engine, will be trying Ford again today

[toadster]

finally got a hold of Ford, they're thinking it's the engine harness... will reach back out tomorrow, hopefully with a harness in shipping!

[Rsnake]

Idle and startup issues resolved and might be informative to other Coyote users.
I jumped into this thread a while ago and thanks to snowman on the forum he has both issues resolved.
The high idle issue is a Ford programming error as the pathway in the idle torque value needs to be -41 and ford has it set to 41. Snowman assumes it's a error in part on the person who copied the Ford Mustang tune to the crate motor tune and missed the negative. Once changed to -41 it idles at 700 and stays at 700 instead of jumping to 850+ after a few seconds.
My second issue was the running rough for 10-15 seconds on startup. After Snowman looked at some data logs he realized I had the O2 sensors reversed. Once I changed them that issue is resolved as well. I drove 75 miles today and it runs perfect. Cannot believe I lived with this for two years.. I will put up a video with details on my YouTube channel. Cobra Daytona Build in the next week.

[TXeverydayDad]

Resurrecting an old thread. @toadster, I assume you got this resolved. What was the resolution?