OK I just bought a 1991 f350 utility body auto with 5.8 and single rear wheels. The truck has been sitting for about a year. When I took it for a 5 min test drive it seemed fine.I went back the next day to pick it up while I was warming it up it stalled twice so I thought it was low on fuel ,so I put 5 gal in it. I left to drive home but while I was still in the lot where I bought it I went to pull away and it felt like the emergency brake was on like it did'nt want to go, after a min or two it started to drive ok.About 3 miles down the road it just stalled as I was driveing so i rolled into a parking lot after I got it started it was running rough it went high idle to low idle and the check engine light went out and came back on. after stalling 6 or 7 times I got it home. The next day I got some injector cleaner and 10 more gal of high test I thought maybe it just had old gas but its still running bad so i changed the TPS and cleaned the throtal body.Now it is not stalling but it is running at a high idle and rich,I can see black exhaust and if you try to drive it it has no power, the same stuck feeling as when I picked it up. I bought a code key to read the check engine codes but when I hook it up The light just stays lit and will not give me any codes,tried a few times ??? Also when you turn the key to on the fuel pump keeps running. The only other thing I can tell you is the guy I bought it from said they just replaced the ignition module. Ok Where should I start ? One other thing the tube from the EGR is broken off at the exhuast but I dont know if that would cause all the problems ??

 

that could cause problems with the egr tube being broken off... you can check the engine codes with a piece of wire also, go to fordfuelinjection.com for directions on how to do this. The egr tube being broken would cause it not to run properly and could cause your rough idle condition and stalling when cold. Could also be any number of vacuum leaks, electric problem, fuel pressure issue, or something else. Your best bet is to get the codes and look them up on the same web site and go from there. I hope everything works out for you and keep us posted on what you find

 

The fuel pump running constantly and the fact you can't get any codes points to a bad computer, I suggest you pull it out and inspect it for corroded connector pins or any signs of corrosion damage inside, if you find either you'll need another computer.

 

OK I removed the computer all the pins look perfect,no corrosion. I also checked the fuel presure at the rail it has 38 lbs with the key on and stayed at 36 lbs when I turned the key off . I think the stalling was bad gas becouse it is not stalling anymore. It is hard starting when cold, It is idleing at around 1500 and black soot is coming out the exhaust and still has no power, it pops if you try to accelarate too fast. what should I look at next??

 

Sounds like the computer doesnt know you are accelerating. Did you check to see if the fuel pressure regulator doesnt have fuel on the vacuum side of it?

 

I'm not sure where the fuel presure regulator is ,do you have any links to a picture of it? Or point me in the right direction ? Thanks for all the help so far this truck is driving me crazy.

 

I am wondering if the vacuum line to the fuel pressure regulator has broken off?

 

Ok I changed the high idle motor checked the fuel presure switch that seems ok. I got it running pretty good but it still feel short on power I am wondering if there are any sensors in the trans ? I think it has the e4od trans I am trying to locate a computer becouse I still can get no codes and the check engine light is still on. Any thoughts on the trans feeling like its stuck or draging ?

 

Did you count the gears, as it's shifting? Maybe it's not even going down into first, and is just starting in second? Or third? LOL I dunno...just an idea. I don't like automatics, and I know even less about them....

Maybe try holding it down in first, manually, and seeing if it gets out of the hole any quicker? All that would do would be to prevent an upshift out of first, however--I don't believe it would force it into first, where it should be starting out, anyway, if in fact it was not going into first to begin with.

Good luck.

 

I have to agree, PLUS.

The same thing happened on my '88. Couldn't get a code but then when it did, it said the EGR was faulty. I replaced the EGR and the EGR sensor and the code still said faulty EGR. I replaced the processor. Problem still didn't go away.

I ultimately found a chaffed injector wire under the intake manifold that I believe was shorting out th e wohole thing. I taped up the wire and have been ruunning smooth for the last 12 years.

Tim

 

Yes he has a bad computer.