5.0L won't start, need help!

[Brian Linn]

My Roadster won't start and I'm running out of patience. The car was running fine and then one day I tried to start it and nothing. It's a 5.0L with an A9L ECU. Nothing had been changed when the problem started. I noticed that when I turned the key to run but not all the way to start you could hear the pump running but it would not shut off. After some unsuccessul diagnostics I posted the problem on the other forum. One respondent said that he had the same issue and it was a bad ECU. I sent the ECU off for repair and it was returned supposedly fixed. The ECU is back in the car now but I have the same problem. The pump runs, does not turn off and the engine will not start.

I have an Aeromotive pressure regulator with a gauge on it. The guage never moves even when I adjust it up or down. I checked the fuel filter and it flows freely. I've pulled the supply line going to the fuel rails and get a good flow of gas. The regulator is installed after the rails. I'm hoping that the guage is just bad but I'm not sure how to test it. I guess the regulator can go bad but it's just a diaghram and a spring, right?

If the regulator is bad will the pump just stay running?

Any help is greatly appreciated. The car has been sitting now for probably 2 years and I've got to get it running again.

Thanks,
Brian

[michael everson]

The fuel pump prime is controlled by the computer. Even at 0 pressure it will only prime for a couple seconds. The computer doesn’t know if there is pressure. Sure seems like the computer is at fault. Maybe someone could lend you a different A9l to try. Try pinching the rubber section of the return line to see if pressure builds.
Mike

[Xkuzme1]

Take out the chip near the base of the distributor. I think it’s called the pip. If it starts, then it is computer related.

[mburger]

This is likely more comprehensive than you are looking for, but lots of good troubleshooting info for an A9L.
I wish I still had my spare A9L. It got lost during one of its loans.

https://www.stangnet.com/mustang-forums/threads/1990-5-0-a9l-and-tfi-sensor-help-please.904981/#post-9129075

I also want to mention a very common issue with the A9L is three capacitors that go bad. They usually go visibly bad. Leaking or expanded. Replacing these three caps fixes it. I’m not aware of any other “repairs” that are normally done to these. Since you sent yours out for repairs, I’m assuming this was done. Easy to check!

https://thefactoryfiveforum.com/attachment.php?attachmentid=103030&d=1551504296

https://thefactoryfiveforum.com/attachment.php?attachmentid=103029&d=1551504286

https://thefactoryfiveforum.com/attachment.php?attachmentid=103031&d=1551504305

[Brian Linn]

I'm running an MSD distributor so no PIP

Arguably one of the worst things I did on my build was mount the ECU behind the dash. I was thinking it would be out of the way and wouldn't clog up the passenger footbox I guess. It took me half a day to get it out of there to send off and another half day to get it reinstalled. Is there any way of testing the ECU without trying it in another car? I guess what doesn't make sense to me is if it truly is the ECU, what is the chance of the ECU going bad at the exact same time as the regulator and/or the fuel guage. Is there a way to test the guage?

Another thing I just remembered. When the fuel pump was running it started making a weird vibration type noise and then several times it would make a clicking noise that seemed to be comining from under the intake area. I tried to find out where exactly but couldn't figure it out. Possibly the return line that goes from the driver side fuel rail? Just weird, the only thing running was the pump. I could hear gas running back to the tank but the return line is stainless so I couldn't squeeze it like Mike mentioned.

[Railroad]

Pump might have been cavitating, or pressure line may be loose from pump to hard line. Clicking under the dash, sounds like a relay. Pump may be going bad. I have not read all the responses, so this may be redundant.

I was exposed to a 5.0 that was running fine and would not run.
For some reason it lost voltage to the MAP sensor. I think we piggy backed 5 volts off the TPS and it cranked up and ran. Just something to consider.

[Brian Linn]

The pump is new, doesn't have more than a few miles on it. I checked the lines and all seem fine. The clicking does sound like a relay clicking I guess but what relay would be in the area under the intake?!! I'll try to add another can of gas this weekend and see if that makes a difference if the pump is cavitating. I emailed the company that did the ECU rebuild to see if they have any ideas or what my options are.

[j.miller]

Check your fuel pressure. You say new pump....why is that? was the old one bad or were just trying to trouble shoot by changing parts...the reason I ask is that I have seen the rubber on the pump come off several times ....Pump runs, no pressure, loose hose on the pump itself.....Just spit balling...da Bat

[Brian Linn]

I replaced and inline pump with an in tank pump recently. I took the car to get a dyno tune and the tuner noticed that he was not getting enough fuel pressure when the engine was under making pulls on the dyno. The fuel pressure was dropping too low for him to successfully complete the tune. I replaced the pump per recomendations on the other forum. The car was running fine after replacing although I have not been down to the tuner to finish the tune yet.

I ordered another guage last night to see if the one I have is faulty.

I contacted the company that did the ECU rebuild. He had me check the voltage across the terminals on the radiatory coolant sensor. I haven't heard back from them yet but they did say they would look at the ECU again if need be. I've got a Moates Quarterhorse on the ECU, I'm wondering if maybe that might be an issue as well.

[Just puttering]

You probably should have started your thread with " I've got a Moates Quarterhorse (QH) on the ECU, I'm wondering if maybe that might be an issue as well. ". Not a week later!

"The ECU is back in the car now but I have the same problem."

Also, be specific, is the QH plugged in or are you trying just the ECU?

A rule of tuning with these - If your pump will not turn off after key on (should run for 3 sec.) do not try and start the car, the tune is bad.


"The car was running fine and then one day I tried to start it and nothing."
"The car has been sitting now for probably 2 years and I've got to get it running again."

Was the car running lately? OR 2 years ago it ran fine then nothing?

Do you have the tune on a computer to reload on to the QH? They have a battery to keep memory, after 2 years and a dead battery (QH not car), you no longer have the tune on the QH!
Pull the QH out of the ECU and try key on, DONT start the car! does the pump shut off after 3 sec?

What has been changed from stock on the engine? or, why are you running the QH?

FYI - The QH is a tuning tool. Although you can leave it on the ECU permanently, There is a board specifically designed for long term use (I forget the name) that has no battery and will not loose the tune like the QH will!

On the fuel side, until you have good pressure, no use in trying to start the car, It wont! Maybe the pressure relief is gummed up from sitting or stuck open? either way, you need key on - 3 sec on the pump then off- fuel pressure at the guage and then you can think about trying to start it!

After re-reading the thread, your dyno tuning person could have been guiding you on these things? If you are not talking to him, you should! I would think that is why you are paying him to tune the car!!

Good Luck

[Brian Linn]

I'm gettting closer!
I removed the Moates Quarterhorse off of the ECU and now the pump runs for 3 seconds and turns off as it's supposed to do. I replaced the fuel pressure guage on the regulator and am getting about 55Lbs of pressure. I charged the battery over night. I drained my tank and put in fresh gas. When I try to start it I get the slightest sputter but it won't fully fire. I get no exhaust smell like it's firing at all. I checked all my connections under the hood and everything seems good. What should I check next?

[Just puttering]

My first response was from direct experience working on mine!

It feels good to be moving forward, I know...

If I was to ask you questions from your last post, where you ask what to check next, I would retype most of my first reply!

[michael everson]

If its sputtering, it will likely start. might still be some old fuel in the lines. Try starter fluid or raw fuel in a spray bottle right into the throttle body. Be very careful.
Mike

[Brian Linn]

Mike, I'm running a Vortech which makes it a bit more difficult. Would you give it a shot of starting fluid on the filter of the MAM? I just drained and replaced the gas.

Just Puttering,
So now the QH has been removed and I'm just working with the ECU.
The car has been sitting for about 2 years. It was running fine before then but just one day it stopped. I sent the ECU out for rebuild, possibly the problem was not the ECU and it was the Quarterhorse all along. The Quarterhorse was added because of modifications, Vortech blower, 42Lb injectors, de-smogged, ProM80, Cam and AFR heads etc.

[rich grsc]

Mike, I'm running a Vortech which makes it a bit more difficult. Would you give it a shot of starting fluid on the filter of the MAM? I just drained and replaced the gas.

Just Puttering,
So now the QH has been removed and I'm just working with the ECU.
The car has been sitting for about 2 years. It was running fine before then but just one day it stopped. I sent the ECU out for rebuild, possibly the problem was not the ECU and it was the Quarterhorse all along. The Quarterhorse was added because of modifications, Vortech blower, 42Lb injectors, de-smogged, ProM80, Cam and AFR heads etc.

That info should've been noted in the first post.??

[Just puttering]

Please post a picture of your engine, be sure it shows the passenger side Efi setup!

[Brian Linn]

Let me know if you need any other picture or a closer shot of anything.
I appreciate everyone's help.155117155118155119155120

[Brian Linn]

Just Puttering, I notice you're also running a Vortech. Did you install a blowoff valve and if you did how did you plumb it? You can barely see the cobbled together temporary mess in the first picture :eek:

[Xkuzme1]

Have you tried a spark tester light? Throw it on a spark plug or two, throw it on your coil wire. Sounds to me like it’s a spark issue.

[Xkuzme1]

… and I hate to do it… but I’m gonna ask again. You said that because you have a MSD distributor, you don’t have a PIP. What I meant to say was SPOUT not PIP. But according to the picture, you have a FTI built into your distributor… which indicates that there is still have a MSD distributor AND possibly are still using the SPOUT. Near the base of the distributor is a gray thumb drive looking piece (spout). Find it an unplug it. If it starts, it’s your computer. You can buy a rebuilt computer from NAPA for $100.

[Just puttering]

Brian,

This thread started out kinda wrong. You got people started with your first question, and then built on it and kinda side tracked your own thread. I have been so frustrated with the efi on my car, I did the same thing!

I want to go back to the basics, start over or from the beginning!

1. stop trying to start the car! You are not going to run it on the stock tune. I know answers or ideas come slower than you may like, but this will take time to sort.

2. There is a maf and injector set that fools the ecu and will run stock. I do not think you have this or you would not need the Qh

3. Did you build the engine or was it built for you or buy the car with it? Where did the qh come from? Do you have the tune off of the qh, do you have a computer to plug into the qh? I am trying to figure how much you know about the ecu, qh, and tune that the car had!

4. You talked about a dyno tune, was that lately or in the 2 years ago part?

I guess give us a time line of 2 years ago it was running, then ..... no, go farther back did it always have the qh when it ran, same engine all along. Blower during this time?

[Just puttering]

… and I hate to do it… but I’m gonna ask again. You said that because you have a MSD distributor, you don’t have a PIP. What I meant to say was SPOUT not PIP. But according to the picture, you have a FTI built into your distributor… which indicates that there is still have a MSD distributor AND possibly are still using the SPOUT. Near the base of the distributor is a gray thumb drive looking piece (spout). Find it an unplug it. If it starts, it’s your computer. You can buy a rebuilt computer from NAPA for $100.

I’m no expert but I think you are over simplifying what that does! Removing the spout stops the distributor advance and makes the computer run on its base tables, if you run the car with the spout out you will likely over heat the engine! Also the op stated he sent in the ecu not that they couldn’t send it back broken! You are also asking him to pull it and start a highly modified engine on the stock Ford tune for a 5.0?

[Brian Linn]

OK, let me try to remember the time line for you.
I bought a shortblock and built it from there. It has always had the Vortech, heads, injectors, MAF flow, Cam etc. The engine started and ran with the stock ECU although of course it was rough and the hydrocarbons would burn your eyes if it was run long in a garage :) When it was in the gocart stage I had it trailered over to a local guy who had a Dynojet and was building and racing Mustangs and he was going to tune it. He added the Quarterhorse. Things started going bad at that point. He stopped working on it, he wouldn't answer my calls, I would drive over there on weekends and nobody would be there. I finally had an attorney send him a letter demanding the car back. Finally he called me, delvered it back to my house but it was not running any better than when I trailered it to him. I have not idea what was on the Quarterhorse if anything. Like I said the car still did not run well at all. Another tuner was recommmended but he was a couple hours away and I couldn't drive the car to him the way it was running. A friend of mine had a trailer and we trailered it down to him and he tried to tune it but had problems with the fuel system. He said that when the motor was loaded up and the blower was building boost he was losing fuel pressure. He recommended swapping out the Walbro external pump with an intank pump and bring it back. I swapped the fuel pump and was waiting on a time I could line up another trailering trip back down to the tuner again. My friend who had the trailering rig got sick - very sick and I lost the motivation I guess.

I gave up on the car for a year or two, I would periodically start the car and let it run and it always started after a couple of cranks. The current problem started probably a year and a half ago. I tried to start the car to let it run for a bit and it would not even sputter. I also noticed that the pump would not turn off if it was just left in run. I posted on the other forum and the consensus was that the ECU was bad. They made it sound like it was probable considering the A9L was 30 years old that the capacitors were probably bad. I dismantled the dash and pulled the ECU out, sent if off for rebuild and got it back. I put the ECU back in and the same problem persisted as before. That's when I posted this topic on this forum. Since then I did get the Quarterhorse removed from the ECU. That certainly had something to do with it because at least now the pump turns off after 3 seconds or so. I also think I hear it trying to sputter slighly. At least the rhythm of the engine turning over has a different cadence early on although I don't get any burnt fuel smell at all out of the pipes.

I appreciate you guys helping me figure this out. Let me know if anything needs clarification or more detail.

[Xkuzme1]

The reason I’m asking this is because…

I have a similar setup. My car wouldn’t start. It occasionally acted like it was going to start. I put a spark tester on it. Occasionally I would see a stronger ignition light. When I pulled the spout chip, my car started up immediately. It ran fantastic (except for being out of timing). That told me that it was indeed my computer. I bought a new computer for $100 from NAPA and my car has ran perfectly every since.

So my questions are based on my history of a similar issue.

X

[Brian Linn]

XKuzme1, I'll pick up a spark tester and check that out.
Thanks,

[Flip Smiley]

Brian, is it possible that the distributor slipped or was inadvertently moved? May even want to check the distributor gear for wear or broken teeth? While working on mine I dropped the distributor back in at 180 degrees off and it sounded a bit like you have described. No pro hear, just past experience.
Flip

[Brian Linn]

Flip,
I don't think so, the distributor has not been out or moved in years.

[Just puttering]

Just got home and have to leave again at 5am so a couple of things to start.

Item number 1 - learning how to tune the A9L (or P) is not for the faint of heart, there is a lot going on and tuning one will make your head hurt!

I think you will need the QH working! check its battery!

get a PC cable that will plug into it, hopefully you have a laptop to use with it.

With the new fuel pressure gauge, turn key on - so the pump comes on - key off - what is the pressure? how about 20 or 30 sec later?

download tuner pro RT http://tunerpro.net/ I forget the difference of the reg and RT, I got both but have just used the RT.

Read up on anything you can find on the tuner pro site! Get familiar with how it works! I am trying to remember all the steps, but may miss one. Use what the web site states first and foremost!

With this and the QH you can start working with the A9L.

I would try and see if RT can see the QH with out the A9L (unless they say dont do that)

Still, dont try to start the car yet.Then see if you can get RT to see and talk to the QH with the A9L (I think all you need is key on) also, do NOT plug and/or unplug any thing with the key on!

Try and pull the tune off the A9L -

This is good first step, There is more to work on, I just have to remember what I did and the steps involved.

Good luck!