You are way beyond me, I just thought the other fuel filter could be the problem. I did have early-on problems with the 1985 mostly related to the fuel-pressure regulator and MAP sensor. After that, the truck ran pretty darn good for literally forever. Then, I sold it at a good price to a friend and it ran pretty darn good again for literally forever. How many miles on yours? Any idea as to original owner service assuming you are not the original owner? I sold my 1985 over 8 years ago and although I knew it well at the time, memory is fading. But, I sure don't mind trying to help if I can. One more thing and sometimes simple is better - be sure the wiring connecting everything to the ECM and it's various components is clean and tight. Remember, you have one of the very first V-8 EFI engines ever produced. It is reliable and strong and frankly I think Ford did a remarkable job on it, but the only time my 1985 left me stranded was due to a poor wiring connection. I imagine you have already figured out that most of that electrical wiring doesn't look too strong. And, no- I don't know exactly where. Had it towed to the dealer and for almost nothing they fixed it. The only time that truck let me down.

 

Just another thought to those with older Ford trucks. I did sell the 1985 a long time ago, but I still own a 1988 F-250 4X4. It has a 460cid EFI with 5-speed manual OD and 3.55 rear gears. The old guy runs great most of the time and gets believe it or not an average of 13 mpg running around town and in and out of the country even at 170,000+ miles. Anyway, the worst problem I ever had with this truck and one the dealer could not find - had to do with the vacuum lines that run around and thru the cruise control system. The truck would run erradically off and on and finally started stalling - no computer codes over and over - the cruise still worked fine. The vacuum lines on this cruise control system run in major turns and circles. Open those turns and circles up and you may find wear holes - mine were real holes in the hose. If so - you may find the source of your major vehicle operating problems - vacuum leaks from old hoses that no one thought to replace before.

 

yeah this truck is very amazing, I looked over all the vacuum lines again... and no cracks, also blew in a few of em with my thumb on the other end and no leaks... I drove it another 60 miles today, and still nothing, so I think what happened was that the EGR valve stuck open and it caused that terrible running, then after driving and running over big potholes I think it unstuck.... As far as mileage I think it has well over 200,000 but when I got it about 3 weeks ago, the speedo wasn't working, and the previous owner said it hasn't worked since like 97 or somethin... the only problems Ive had with it so far are, leaking tanks, bad fuel pumps, bad selector valve, bad intake gaskets, bad ACT/ECT sensors, bad speedo. Other than that she runs excellent. Actually it does consume a good bit of oil, and theres oil coming out of the head gasket on the passenger side, but Ill try and get about 10,000 out of her b4 I tear apart the engine... Ive just been adding a quart of oil each time a fill up with gas... it was actually leaking a lot worse but the intake manifold gasket wasnt installed right so I replaced it and it leaks a lot less... Any help is welcome as Im just an average guy trying to figure this out, this is my first ford btw, and Id have to say it actually runs pretty dam good.

 

I'm just an average gal that has spent many hours looking at things on trucks, reading manuals and finally figuring out how to at least half-way fix a lot of things. You might want to go around that old 302 engine and tighten the valve covers. I used to have to do that periodically - probably about every 15,000 miles. There was always oil seepage, especially toward the rear. Then, the oil pan always dripped from the front of the old truck too. I quit trying to tighten those bolts when I broke one. Good luck with the old girl. With a little TLC you could probably make it run for "literally forever".

 

Thanks again 4 the help. Gonna go have a dam forgot to change my clocks back lol.

 

Sounds to me like the old truck needs to go for a good, long drive. Take a chance and take her for a spin - a few hundred miles worth. Might clean a bunch of things up including the old exhaust by-pass stuff (EGR).

Good luck with her. I love good, old trucks, not exactly sure why - guess they always offer a challenge (assuming they get you home too!). Just kidding - go for a nice, long drive and report back.