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I have a 1992 F-150 XL 4.9 Engine 2WD, standard transmission.
I had a bunch of problems with the truck and got them all fixed but the engine still sputters when hitting the gas, mostly at 1500 rpm. Doesn't sputter when idling, but does idle a bit high.
The shop I took it to replaced the ECM Computer, MAP Sensor, cleaned out the gas tank and replaced fuel filter. Also had a tune up done as it needed one anyway.
Before this was done the truck would idle sporadically and then stall out and the check engine light was on. It's not doing that anymore, no check engine light on now and I drove it around for an hour and it didn't die at all.
But I am still having the engine sputtering problem. Seems to even out somewhat at low rpm or if I'm going hard on the gas pedal though.
Any insight to what might make it run badly after everything was checked and repaired.
I assume the shop checked the fuel pressure and it is okay. I would suspect clogged injectors but that is just a wild guess. Put a bottle of Gumout for high mileage engines in the gas, maybe a half tank. Not sure what the "tuneup" consisted of? Did it include new spark plug wires?
Yeah, the tune-up included plugs, wires, air filter, distributor cap, etc. I was thinking the fuel injectors might be a possibility but there was nothing wrong with them as far as I know when I brought it there. They did check the fuel pressure and it was ok.
The thing that bothers me is how could so many parts go bad on the truck all at once. I can see one or two things causing the problem, and the computer was definitely bad. They showed it to me after taking it out of the truck.
Hello, my son has a 1994 F150 with the 5.8 engine. His truck is acting almost exactly like yours. The difference is his sat for about three years. We have been through the fuel system & replaced all ignition components. We noticed once you remove the distributor cap and rotor, the top of the distributor shaft wobbles quit a bit. Not sure if this could your problem or ours as well, but we are going to replace the distributor tomorrow.
Hello, my son has a 1994 F150 with the 5.8 engine. His truck is acting almost exactly like yours. The difference is his sat for about three years. We have been through the fuel system & replaced all ignition components. We noticed once you remove the distributor cap and rotor, the top of the distributor shaft wobbles quit a bit. Not sure if this could your problem or ours as well, but we are going to replace the distributor tomorrow.
Thoughts???
Thanks
Ken
If the dizzy has alot of play that may be causing some issues but may not cause all. If the timing is off at all it could cause a issue. My one truck was one tooth off it idled rough and ran rough unless speeding up. Have you unplugged the vac line / connector on the EGR (Exhaust Gas Regulator) if this has gone bad and is not functioning right unplugging should cause the truck to level out and run right then you would know this was your issue. I would definitely check this both of you cause this may be the issue. The gasket sometimes gives and then it run like crap cause its getting air in it or sometimes they plug up or if its older the plunger and diaphragm give out and cause it to not work right. This is one thing I check when a truck isn't working right if its older and everything else has been done.
I think I'm going to take my truck to a Ford mechanic to see what they can find. I'm getting so many different suggestions on what could be wrong with it and I've fixed so many things that were in need of repair already. I want to find out exactly what's causing the problem. I'll post an update on this thread once I get a definite diagnosis of the problem.
Thanks for the suggestion Rich. We did replace the distributor, the engine runs slightly better but we still have the problem. We also tried disconnecting the EGR, no help. We are thinking about replacing the ECT (Engine Cooling Temperature) sensor. The engine seems like its loading up or running rich. Thus the ECT is not telling the computer the engine is warm and allowing to much fuel to the engine. If we gradually open the throttle the engine will accelerate just fine. But not if you do it in normal fashion.
Hello all, well we replaced ECT with no help. We performed trouble shooting on as many sensors as we could locate and identify. All checked good. We noticed even when warm when you first crank it up it will accelerate just fine for about 3-4 seconds, then it starts to miss again. We removed the PCM and opened up to find what looks like little blue capacitors with one leg corroded or burnt away. So now we are looking for a PCM.
Does anyone know what specific number on the data plate we should be looking for when searching for a replacement?
I am not sure on what number but you could look on like napa if you now what transmission etc in the truck and find one that may lead you to see what numbers needed. I tried to cross the numbers in the picture and non would cross in napa (I have a shop account from when I worked their). It may even help to call your local ford dealer or run over their and ask them.
A-1 CARDONE 785883 {#F4TF12A650SB, F4TZ12A650SB} Reman. Engine Control Computer Info
Automatic trans.; XL Model; XLT Model; Trans. code E4OD; Units are pre-programmed at the factory.; I.D. #(s) F4TF-SB; with Federal Emissions (Only 4 Remaining)
09-14-2016, 07:48 PM
