Weird problem: Car shuts off while driving; starts 5 minutes later? Plus gauge issue

[David Hodgkins]

I've starting experiencing a problem. On several occasions while driving, the roadster just shuts off. Seems to happen under light to no load. I still have fuel pressure, but no spark (I think). In all cases (it's happened 4 times now) I fiddle with the coil wire for a bit and after 5 minutes or so she fires back up and runs without issue. Doesn't appear to be a vaperlock as I'm not usually running full temperature at the time, or in hot weather. I run a 302 with MASSFlo (remember them?). This only started happening recently. The car has 15K miles on the odometer

Could a coil going out cause such an intermittent issue? Any other ideas? It's impacting my confidence in taking her out for cruises, and I THINK there's a pretty big on coming up I don't want to miss!!

I look forward to all feedback or questions; TIA

:)

PS I have a water gauge from speedhut that is also going wonky but I don't think it's related. Tapping on the gauge restores function for 10-30 seconds then it starts dropping to zero and back up again, like it's a connection issue. Could it be something else inside the gauge itself?

[Jazzman]

I had a simple crimped wire that caused the same behavior. It happened to be in the ignition circuit, and would occasionally ground out the engine. I can't begin to speculate where such a problem might present itself in your car because I don't know your wiring scheme, but given my limited experience, this is where I would start looking. Perhaps a wire on the water gauge? Good luck finding it. Just what you need: one more thing to get done in the next 10 days!! :cool:

[David Hodgkins]

I had a simple crimped wire that caused the same behavior. It happened to be in the ignition circuit, and would occasionally ground out the engine. I can't begin to speculate where such a problem might present itself in your car because I don't know your wiring scheme, but given my limited experience, this is where I would start looking. Perhaps a wire on the water gauge? Good luck finding it. Just what you need: one more thing to get done in the next 10 days!! :cool:

Is this the gauge issue, or the intermittent stall?

Don't get me started about stuff to do. I'm not even going to discuss current TROJAN issues! Too embarrassing!! 10 days! Thanks for the reminder!!!

:)

[UnhipPopano]

I similar problems with two cars, and they both turned out to be intermittent ground problems with sensors. See if you can get a diagnostic reading when the car will not start. If it is a ground problem, the CPU may have reset and then no diagnostic codes are left to read.

[Jeff Kleiner]

My first thought---MASSFlo uses the Ford EEC-IV distributor (or an aftermarket equivalent) with TFI module. Shutting down when warm then restarting after a short cool down is one of the classic symptoms of a failing TFI module. Coils are usually on or off rather than intermittent.

Sounds like an internal gauge problem. What brand are they? If they are Speedhut failures are part of the ownership experience but hey, they have great customer service when you need them to send you a free replacement ;)

Jeff

[Jazzman]

Is this the gauge issue, or the intermittent stall?:)

In my case the wire was in the ignition switch loop. It caused the car to die with no warning, then would start up again after a short wait. This happened four times, then the short was significant enough that it would not start again. I towed the car home, opened up the dash, and found the crimped wire that had gotten caught between the dash and one of the dash supports.

The fact that the gauge is acting up is merely a guess of a place to start. It doesn't sound likely to be one single issue. Jeff's answer, as usual, sounds much more educated and likely to be accurate. I hope you find it quickly!

If there is anything I can do to take some pressure off you in the next 10 days, please do not hesitate to ask. We are all looking forward to the Cruise In!!

[Avalanche325]

I agree. Your wire wiggling is really electronic cool down time.

Call Speedhut about the gauge. They have great customer service.

[David Hodgkins]

Thanks guys, I'll pick up a new TFI module after work and see if that fixes the issue. I'll also tear into the gauge itself to see if a solder has worked loose. I've already called Speedhut and they are OK with that. Keeps me from having to waste time waiting for a new gauge...

:)

[Big Blocker]

David,

Having gone thru this issue a few times myself, I have to agree with Jeff . . . the TFI module is heat-soaking and quitting. The best test would be to have a cup of ice water handy and immediately throw it on the TFI module, car should start right then if tried.

FWIW, due to 2 incidents with TFI issues, I have relocated my TFI module to the PS footbox, away from the radiant heat of the engine. Haven't had that issue come back since.

I used to be so aware of the possibility of this happening while out on the road that I always carried a spare TFI in my tool kit.

Also worth noting, if the TFI is the gray unit, that is the "Push-start" unit and should start with a push as opposed to cranking. If it's the black unit, that won't work.

Doc

[David Hodgkins]

/..If there is anything I can do to take some pressure off you in the next 10 days, please do not hesitate to ask. We are all looking forward to the Cruise In!!

We've entered the final countdown so sleep is optional! Event planning is going well; I'm currently working on badges and car placards. They will both be personalized this year! NO MORE SHARPIES!

I'm really looking forward to the cruise-In this year! I have a bit of a personal surprise waiting for everyone!

:)

[David Hodgkins]

David,

Having gone thru this issue a few times myself, I have to agree with Jeff . . . the TFI module is heat-soaking and quitting. The best test would be to have a cup of ice water handy and immediately throw it on the TFI module, car should start right then if tried.

FWIW, due to 2 incidents with TFI issues, I have relocated my TFI module to the PS footbox, away from the radiant heat of the engine. Haven't had that issue come back since.

I used to be so aware of the possibility of this happening while out on the road that I always carried a spare TFI in my tool kit.

Also worth noting, if the TFI is the gray unit, that is the "Push-start" unit and should start with a push as opposed to cranking. If it's the black unit, that won't work.

Doc

I like the ice water idea.

re "Push Start": Actually, the first time it happened we tried bump-starting the car and that didn't work. Is that what you are talking about?

:)

[Big Blocker]

Yes, exactly. When mine quit for the first time, I just replaced the TFI and went on my way - time to replace it was probably more then enough time to let it cool and most likely would have started up.

Second time, I had learned about the "push-start" function and was actually on the freeway when it quit. I was about to pull over to the side and remembered that I have the gray unit. Slipped into gear and dropped the clutch, car fired right up and worked fine until about two blocks from home. I repeated the process of dumping the clutch and she fired right up again. Replaced the unit when I got there.

I carry one now, just in case, even with the TFI relocated . . . and the special tool to do the swap.

Doc

[Big Blocker]

David, Are you still running the original EEC?? I replaced all the capacitors recently in mine and found some "warmed" traces on the circuit board, fixed that along with the Caps. It was causing an intermittent mis-fire.

Doc

[David Hodgkins]

David, Are you still running the original EEC?? I replaced all the capacitors recently in mine and found some "warmed" traces on the circuit board, fixed that along with the Caps. It was causing an intermittent mis-fire.

Doc

Yes, I'm running the EEC I got with the system in '06. Should I take it somewhere to be checked?


:)

[canuck1]

I had exactly the symptom you are experiencing (car shutting off, no spark) that went away when I replaced with the correct Motorcraft brand TFI module + TFI grease. I have a Mass-Flo style system as well, using Ford ECM w/chip, etc., with a few components I sourced myself. My original MSD distributor came with an MSD labelled module and they had a reputation for being unreliable. I know it doesn't guarantee to fix your problem, just relating my similar experience.

Good luck with the event!

Sean

[David Hodgkins]

https://www.pepboys.com/parts/ignition_system_components/ignition_modules_components/00264/1992/FORD/MUSTANG/0/V8-302%2520%25205.0L

Am I better of going to Ford? What about NAPA?

[videodude]

David,

Use a MotorCraft TFI, regardless of where you buy it. Any computer from an early Mustang is potentially suspect, as they are all 15+ years old. There are 3 capacitors that need to be changed, not a hard job but a necessary one.

Video

[cgundermann]

Second/third vote Dave for MotoCraft TFI.

Chris

[David Hodgkins]

Motorcraft TFI ordered. Those suckers are expensive! Over $90 bucks out here in Cali.

:/

[Big Blocker]

David,

X3 (or whatever number we're on now) on the FORD TFI. The aftermarket ones SUCK! Don't ask me how I know. You'll need a special tool to replace it. It should come with the HEAT TRANSFER paste - DO NOT USE HEAT-SINK paste, it's non-conductive and will not draw the heat away from the unit, it's an insulator.

Doc

[David Hodgkins]

Today I picked up the new TFI module, but it came without grease. The Ford guy said "just use dialectic grease".

Is he wrong? If so, where can I pick up the proper grease? I went by another Ford dealer but they were closed...

:)

[Big Blocker]

David,

Go by any auto parts store and see if they have "Artic Silver" Thermal Conductive paste . . . A little $$ but worth the price knowing what is does for your TFI.

Doc

[David Hodgkins]

David,

Go by any auto parts store and see if they have "Artic Silver" Thermal Conductive paste . . . A little $$ but worth the price knowing what is does for your TFI.

Doc

Awesome. Thanks!

:)

[Big Blocker]

Sorry Dave, that's supposed to be ARCTIC SILVER . . . damn skinny fingers missed the first "C" by a mile - of all the times for auto correct to not work! Ha!

Doc

FWIW: "A dielectric (or dielectric material) is an electrical insulator"

Go tell the {FORD} parts guy he's bonkers and doesn't know anything about dielectrics or their use in an electrical application where heat transfer is required.

We're not concerned with electrical conductivity here, the module is encased in epoxy, completely isolating its circuits from any grounding. What we need is heat transfer so the internals don't get past their operating design [max] temperature (257°F). Go here if you're interested about the law suit that FORD lost due to faulty TFI Modules ---> https://www.autosafety.org/ford-tfi-module-national-class-settlement/

[videodude]

Dave,

If, after replacing the TFI module you are still having an intermittent problem, PM me and I'll pick up the capacitors you need and fix your EEC at the BBQ. It's not hard and won't take long. I just need to know ahead of time so I can pick up the parts and pack my soldering tools.

Video

[David Hodgkins]

Dave,

If, after replacing the TFI module you are still having an intermittent problem, PM me and I'll pick up the capacitors you need and fix your EEC at the BBQ. It's not hard and won't take long. I just need to know ahead of time so I can pick up the parts and pack my soldering tools.

Video

Wow, Allan, that's quite the offer! I'll let you know my status ASAP.

:)

[cgundermann]

Very, very cool - love this group!

Chris

[Big Blocker]

Allan,

Don't forget to pack the 2 different sized Torx screw bits . . .

I'll be right there with you at the BBQ - two sets of eyes are always better.

Doc

[David Hodgkins]

I’ve gone to O’Reilly s and pep boys and both do not have the proper grease. Are there any other alternatives?

[Just puttering]

Is the thermal compound the same that you use on cpu's. If you have a frys electonics or similar, you can find it there!

Is there any reference material on the eec caps that need replaced? I should check to see if mine has been done! I have to pull it out and check it this next week, so checking the caps at the same time would be a good idea!

[videodude]

To all,

LOTS of information on cap replacement available online. Google for "A9L capacitor replacement". A word of warning: DO NOT ATTEMPT THIS IF YOU ARE NOT FAMILIAR WITH PROPER PROCEDURES FOR CIRCUIT BOARD COMPONENT REPLACEMENT!! It's not hard to do, if you know what to do. But you can make a real mess of it if you DON'T know what to do.

Just my little word of warning . . .

Video

[videodude]

Dave,

Thermal grease is available at Fry's. A quick check shows it in stock at all stores.

Video

[Just puttering]

We used to have a great laugh when somone would put caps in backwards rebuilding power supplys, sounds like a gang having a gun fight, and boy does it stink, although they were larger caps.

Ahh the good old days!

[David Hodgkins]

This is what I'm replacing:

https://thefactoryfiveforum.com/attachment.php?attachmentid=84446&d=1524378364

https://thefactoryfiveforum.com/attachment.php?attachmentid=84450&d=1524378447

https://thefactoryfiveforum.com/attachment.php?attachmentid=84449&d=1524378436

I used the old credit card method to spead the thermal paste:

https://thefactoryfiveforum.com/attachment.php?attachmentid=84447&d=1524378416

After taking this pic I realized my original did NOT use dialectic grease on the 3 exposed connectors so it was removed.

The TFI module screws are phillips head, not Torx. Can't remember if I changed it or if it came that way?

The car started right up. I'll run it tomorrow to verify.

:)

[videodude]

Dave,

You should still check your EEC for leaking capacitors. I'll show you what to look for at the BBQ.

Video

[AC Bill]

The TFI module screws are phillips head, not Torx. Can't remember if I changed it or if it came that way?

The car started right up. I'll run it tomorrow to verify. :)

I believe Big Blocker's comment on remembering the Torx drivers, was relating to the ECM disassembly, not the TFI.

I guess you better run it for awhile, to see if it stalls out when hot, and won't re-start. Let us know if that solved the issue please.

[videodude]

I believe Big Blocker's comment on remembering the Torx drivers, was relating to the ECM disassembly, not the TFI.

I guess you better run it for awhile, to see if it stalls out when hot, and won't re-start. Let us know if that solved the issue please.

Doc's comment regarding the Torx drivers was for disassembly of the EEC, not removal of the TFI. The TFI "normally" uses socket head bolts attaching it to the side of the distributor that require a special wrench to remove; if Dave had Phillips screws mounting the TFI, they were changed at some point.

Video

[Just puttering]

Opened up my A9P eec and found these - 85033850348503585036

[CdnCarNut]

:eek:

That's why potting gets used on electronics.

[videodude]

Ouch! Well, there are lots of articles online regarding replacement, and the parts aren't expensive. Just make sure to buy replacement capacitors that are 105C (temperature), NOT the more common 85C. It's not a hard job, but you need to be careful that you don't damage the circuit board. Get those puppies replaced!!

Video

[videodude]

:eek:

That's why potting gets used on electronics.

Actually, if you look at picture #2, it clearly shows corrosion from the INSIDE, which potting would NOT have prevented. Boards are potted for industrial security, and to force total board replacement when they fail, which they will. And yes, you're right: sometimes for vibration. But potted boards are a bit** to fix . . .

Video

[Cfehrenb]

Dave - can you give an update on your car. Did replacing TFI make the difference?