BamaGuy

I've seen this problem on hundreds of threads, but I never saw a definitive answer. So I started this thread to follow the problem from start to finish and hopefully help future trouble shooters.

I bought a 1994 F150 4x4, w/ 302 about 2 months ago. It ran rough when I got it, but it was at an unbeatable price. First thing I did was change the fluids and run the KOEO codes. Had 14 codes...I replaced the neutral safety switch, EGR valve, PCV valve, wires, plugs, and cleaned throttle body.

I'm down to 2 KOEO codes now:
173 - system rich
624-EPC solenoid or driver circuit failure

Issues: Shifts hard from 1st to 2nd and into reverse(nice hard clunk). High idle rev at crank, but drops to normal after a few minutes or if I tap the gas a few times. Runs rich, smokes slightly.

I'm going to look over the wiring harnesses and grounds tomorrow and change the fuel filter. Any other ideas?

Aktech

Pull engine vac for you running rich condition.

BamaGuy

It took a while, but I finally got under the truck. Cleaned all the grounds with a wire brush and sandpaper. Then looked at the wiring harness....after 2 minutes I found a broken wire. Sliced the wire back together, now it shifts perfect. That was much easier than I expected.

I used some throttle body cleaner to check for vacuum leaks. None found. After I crank it, I can tap the gas once and she'll idle normal. TPS? I'm going to throw the multimeter to it when I get a chance.

BamaGuy

So I found the source of the high idle. Fuel pressure regulator was bad. Replaced it and now it actually has some power and quit smoking. BUT, after driving in traffic for 10-15 mins I noticed smoke coming for under the hood. Looks like I'm seeping tranny fluid out of my dipstick! I'll let you know what I find out.....