Alright... I'm going to list all the details... About 6 weeks ago my 1995 F150 with the 5.0 302 and 4R70W was running like a dream, no issues.
Then out of seemingly outa nowhere I get a code 41 on my airbag light, so I replaced the Airbag Control Module (blue box under the steering column) and boom, code fixed.
The immediate following day 1/19/25 I'm driving home, and my transmission starts slamming gears, the torque converter is seizing up and killing the engine, all that fun ****. So, I had my truck towed into my local Aamco and they replaced pretty much everything inside and took it for a test drive.
They reported it stalling at complete stops or when idling, I figured this would be something minor since they didn't seem concerned. Here's the present, 1/24/25. I was driving it home from Aamco and sure enough it's dying at intersections and all that, but as I get out on open road the engine starts aggressively stuttering and choking, which led to it dying MID DRIVE at 60+MPH and being very difficult to start, requiring several turnovers. It felt like the engine was choking and the transmission was getting slammed by the engine repeatedly stuttering. So, here's my question for all those much wiser than myself. What could be wrong? The only new thing since I picked it up from the shop is the ABS light is staying on when the engine's running. And there's no CEL codes. Could the Airbag Control Module of caused it all? Or perhaps Aamco is to blame? I'm at a dead-end here. I'm going to start off tomorrow dark and early changing the ACM back to the old one and seeing if the engine sustains ignition. Little scared to drive it again and risk getting stuck on the highway requiring further towing.

(Update as of 1/26/25) I've narrowed this whole ****show down to either the ICM, PCM or PIP. But still no firm resolution

ANY advice would be appreciated, I just need a direction.

 

Sounds like a huge pain! Does it die when idling in neutral?

 

It's not your airbag system because that can't affect the engine. Its not your fuel system, because you mentioned your transmission is getting slammed by the engine sputtering. A fuel problem would give you a softer on-off cycle.
I'm guessing it's your ignition.
It's possible that you damaged your 30 year old ignition switch while removing and replacing the airbag module. That would affect the ignition system.
It could also be your PIP sensor in the distributer or your ignition module on your Riverside inner fender thatll give a similar symptom.
You can wire up some led lights on your dash to monitor your PIP, ICM, and ignition switch behaviors too see which one is causing the problem.

 

It is either fuel or spark that is causing it to stop running.
This can be hard to check but a long hose on the gauge and gauge placed out on the hood or glass where you can see it should take care of the fuel part.
Heck you may find as soon as you hook up the gauge the PSI maybe too low?
Do you have dual tanks and if so what happens when you switch to the other tank?

Spark is a little harder to check. When it happens pull the coil wire from dist. and hold it no more that a 1/4" from the motor block / intake manifold and crank it.
If the ICM (TFI?) is going bad just the time the motor is off and you checking for spark the unit may cool off and you have spark again.
That is why a lot of times it is best to just replace it, dont go with the cheapest you get what you pay for, and see if it fixes the issue. If not you got a spare for when it dose fail just keep it in the truck some place.

I also know with the late 80's trucks running computers, EFI trucks, the main computers are starting to show some strange problems.
If you pop the cover the cap's are showing failure, turning brown, leaking or just blown up.
The ground to the computer I think is by the battery? Might be a good time to go over all the grounds.
Battery to motor, motor to frame, motor to firewall to ground cab.
BTW the computer controls spark and fuel and I think in your case the transmission with the 4R70W.
Dave ----

 

I had a similar issue with my 95. It wouldn't fully stall while driving but had issues. And would stall at idle or almost stall. No codes for the longest time. Then it had codes for semi related things that didn't fix the issue. It turned out to be the intake air temp sensor. It was reading incorrect enough to cause an over fueling issue, but not bad enough to throw a fault code. Check to make sure it is clean so it gets the right reading. Mine was covered in oil from the pcv system.

 

@haveyouherdwithferd Yes it does, I've done quite a bit of work since this point and narrowed it down to the fuel pressure. KOEO I only get 0-10PSI, and if I can magically get it to start it sits at a proper 31PSI before sputtering and dying after 15 seconds or less.

 

You make a fair point with the ignition switch potentially getting damaged. I'm not one for yanking electrical components around when working but I'll give it a good check. What I did discover today is my fuel pressure is miserable. Both tanks read 0-10 PSI with KOEO and IF I can get it to start it keeps a decent PSI of 31-32 with both before sputtering out and dying randomly after as little as 15 seconds or 3 minutes. Doesn't matter if you rev it or let it idle. So far I've replaced the fuel filter and fuel pressure regulator to no avail. I'm going to change out the fuel pump relay tomorrow, so hopefully that fixes the issue. Although I might just have to buck-up and change the pumps themselves since Fords are notorious for their ****ty pumps. Then again, I'll check that ignition switch and see if I screwed anything up.

 

Yeah I checked my fuel pressure today and it's miserable. With 0-10PSI on KOEO but a decent 31-32PSI with KOEO... Before it sputters out and dies after 15 seconds to 3 minutes, regardless of throttling it or letting it idle. I mentioed in a reply to prototypemech all the things I've changed and worked on so far. Including the fuel pump, pressure regulator and soon the fuel pump relay.
Electrically I'm not 100%, I'll have to give that a look tomorrow as well, with that ignition switch that prototypemech mentioned. I've already replaced the TPS (got the proper one for my model and all that), spark plugs, spark plug wires, distributor cap, distributor rotor, ignition coil and battery a few months back. I also cleaned up quite a few grounds awhile back as general maintenance (lot of buildup on a few) But I have my concerns with the brain...

 

Good point, I'll be sure to give the sensor a good look and check for any buildup.

 

Did you have this problem before? It is odd that both pumps would go at the same time. It could be the relay getting weak so that would be a good place to start. But, if that does not cure it, i would only replace one pump to begin with. That way if the problem isn't cured, you only have money invested in one pump.

 

When the key is first turned on and getting to 10 PSI is not good I believe it should get up to normal PSI before the priming shuts down and then should hold PSI for some time.
I dont know what the normal PSI is or the time it should hold but that 30 PSI just seams low.

As a test if it will run long enough trun the key on & off 2 or 3 times to see if the PSI comes up with each time the key is turned on.
Then when running pull the vacuum hose off the FPR and see if the PSI goes up. I also believe it shout but if the pump is weak it will not.
You may be showing 30 PSI on the gauge but when it stops running is it still showing 30 PSI?
If so I wonder if the injectors need more than 30 PSI to push pass the opening and it is running out of gas?
Dave ----

 

Today I replaced the fuel pump relay and the fuel pressure returned to normal specifications. NOW, the damn thing completely refuses to start. There was no spark going from the ignition coil to the distributor, so I replaced the ignition coil plus cleaned up the wires, and that did absolutely nothing. Truck STILL completely refuses to start now. I made 100% sure that the entire fuel system functions, and I've been checking all around the ignition related components for probably the 5th-6th time now with no avail. I'm beginning to really suspect that the brain is completely fried. I'm just trying to understand how the engine functions flawlessly (minus the tranny needing some work) then all I do is replace an Airbag Control Module and the whole truck goes to hell.

 

I replaced the fuel pump relay this morning and got normal PSI. 35 when KOEO, 32 with KOER with regulator plugged in, and a solid 40-41 with regulator unplugged and KOER. It also holds 32PSI when engine is turned off. But it's gotten even better, it ran for about 3 minutes that way this morning before dying instantly while idling. No sputtering, it's like someone just turned the ignition off. So I carefully (with battery unplugged) replaced the ignition switch. Still won't start. I checked the ignition coil, and no spark was going to the distributor, so I replaced the ignition coil. Still won't start. There is physically no spark leaving the ignition coil even though it's new. I'm beginning to lose my mind. Maybe it's the PIP sensor? Perhaps the ICM or PCM? I'd rather not spend hundreds in a guessing game I'm going to lose. I should also note, I'm not getting any CEL.

 

I have heard that the power steering pressure switch can contribute to bogging engine down at stop and turns. I am dealing with what seems to be a skip and am in process of replacing suspected pip sensor which is a pita. The seal at bottom of distributer is almost unobtainable. Amazon still owes me (2) and they will not let me cancel the order yet it has been almost 90 days. Zoro tools had it here in less than 5 days . I checked my computer that looks new with no swollen or ruptured capacitors. I have started looking into possibly going to an edis system, but that takes time to put the pieces together just for ignition. Adding a microsquirt module adds fuel control for $300 more.

 

Step one is to check to see if the red/green wire on your ignition coil is getting 12v power with the ignition switch on.

I mentioned above that you can use LEDs to monitor which component isnt working correctly. Just need a LED and some wire to determine the problem. https://easyautodiagnostics.com/ford...ests?start=4#9

Check out step 7.