I can't figure out my 87 F-150. It has the six in it and I have been trouble shooting it for a long time now. After I start it, it runs for about 10-15 seconds then stalls out. I restart it and it runs for 10-15 seconds and then it stalls out. Repeats over and over. If I try to keep it running it gasps for air and does not like it but, I can keep it running most of the time. After I continue keeping it running and it warms up and kicks into the closed loop cycle it does run much much better, but not good by any means. I have replaced my in-line fuel pump and it is not my in-tank pumps because it has the same symtoms on both tanks. My cap, rotor and wires are brand new with good spark plugs. I have checked and replaced my vacuum lines. After running a scanner it pulled up codes 41-EGO sensor voltage always "lean"(low value) does not switch. 32- EGR Valve position (EVP) sensor or pressure feedback sensor (PFE)-signal voltage is below closed limit or gone beyond set limits. or problems with EGR valve controlling. 25- Knock sensor signal not detected during engine run self-test (dynamic response test). The engine started to run badly immediately after I arched(sp?)my battery terminal to my front fender with a wrench. I checked my timing and after lining up the mark on the big notch my timing light showed 15 degrees. It did not move when I revved up the engine. Am I reading the timing right? Any ideas? I don't know where to go next. Brian.

 

I'm thinking that especially if the problems started when you arced from the fender to the battery, that is the cause. I would guess that the power surge fried something, possibly in the computer.

If you find that it is the computer, you might check with your local wrecking yard to see if they could let you try a computer for your truck before buying it to see if that fixed the problem, they aren't very expensive maybe. I know of a guy who did that around here with a computer for his BroncoII, but he had known the yard's owner for thirty years at that time so he may have got some special treatment.

I'm sure there will be someone else who will answer this who knows a lot more about the computers and electrical system than I do, but that's my 2 cents.

Brian

 

My Uncle's Truck did the same thing when his stupid son hooked the cables backwards. I know, what a idiot. Anyway he went to our local yard and bought a computer for 15 bucks. I guess they are cheap enough. Other places might be higher because this place seems cheap on everything.

Blaze

 

First thing: pull the codes.

 

Steve, if he has these, didn't he already pull the codes?

I think it has something to do with the computer and a fried relay or circuit somewhere.

That's my opinion.

 

It's been many years now but if I remember correctly, we did the same thing in our 89', only we put the battery cables on the wrong posts. It literally blew up the solenoid switch on the fender, blue flames and all. Guess we lucked out, it didn't damage anything else.

 

OK I admit it - I was skimming too fast to read the whole thing before I posted...

 

test

 

Thanks everyone. I guess I will try to locate a new computer. What years are interchangeable? 87-92? So can I swap out any computer as long it has the 4.9 regardless if from a bronco or van? Are there any years that are preferred? Maybe more power in the later years? Brian.

 

'87-88 may be slightly different from '89-95 because of the lower fuel pressure. Call Ford and a few parts stores to see what the interchange is. Most junkyards can tell you, too.

'96 is MAF, so forget that.