1992 F-150 trialsand tribulations
I recently suffered through a marathon troubleshooting effort with my F-150. Understand that my limited automotive experience is on the vehicles I've owned over the years. My profession is as an industrial electrician and in the last twenty five years has been in troubleshooting.
I bought the '92 new when it had 35 miles on it. Right out of the box it had a bad computer and was out of alignment (ruined the new tires for which I was not compensated). I actually had to tell the mechanic that the computer was bad. Since then I have had repeated trouble with the truck, mostly constant parts replacement of items like a radiator, power steering pump, alternator and starter that died before their time, so in comparison to my '99 Taurus, not a fully reliable vehicle. It has only left me once though, and that was for the computer. Yes I am now on my fourth computer in 22 years. No the windshield doesn't leak on it and nothing has shorted out. I took the last one apart and found that the electrolytic capacitors leak after time. This is endemic to electrolytics that I have found in my work.
Last fall just before snow and ice season the truck died on me. I have been having health issues and frankly didn,t feel like working out in the cold, so it sat all winter. I did move it around a bit, but the Taurus got me through the snows. This Spring I was feeling much better so I dragged out the old flash code reader. I got a whole ream of codes (I have gotten better at reading the thing with all this practice) for Engine coolant temp(118)(116), Oxygen sensor reading to rich(173), EGR valve (334),Insufficient rpm change(538), EGR vave (332), and finally the dreaded 998 code (I'm fed up with your lack of ability to fix me and I am ignoring everything and setting the engine to run on emergency settings).
Not knowing what to tackle first I replaced the egr valve and sensor. Still had the code. Replaced the solenoid valve that operates it. Still had the code. After reading in the forum for rough running and stalling I launched out and replaced the idle air solenoid valve, even though I didn't have the code. No change.Somewhere in here I was getting conflicting codes (engine too hot, engine too cold, engine never just right), so I popped out the computer and checked the caps. they were leaing so I replaced it. I replaced the throttle position sensor and saw improvement (incremental). Replaced the MAP sensor and did a complete ignition tune up including coil (I believe in PM) and now I could drive it. I was happy as a clam until I found out that it wouldn't restart hot and I still had the egr code, oxygen sensor and the temp sensor (118).Oh and the check engine light was on all the time now. 117 went away when I replaced the computer (leaking caps again). The symptoms were identical to a carbureted engine flooding, so I did a little research and found out that fuel injection can flood, but it's from a different cause. I knew it was flooding because I could restart by leaving it floored while starting or letting it sit a few hours. Realizing that the injectors were leaking, I nearly panicked. Way out of my pay grade. I bought some Seafoam and ran the **** out of the truck. Now she ran like a top, better than when it was new, but I still had my old friends egr valve, temp and the dreaded 998. Somewhere in this forum I found a thread with a fella who had the same three codes and got rid of all of them by replacing the temp sensor and disconnecting the neg. terminal of the battery for five+ minutes to erase every bad memory of this ordeal.
Phew! For good measure I replaced the fuel pump which I knew wasn't causing a problem, but the clock had about run out on its life. Does anyone know where to get an adapter to the little tire valve size Schrader valve that's on the fuel rail? None of the kits I've seen online have it and as it's usual used for air, I don't trust the seals for gas.
I have one other recurring problem with this truck. It eats mufflers and tail pipes. Rust out from inside. I'm getting tired of replacing them. I was tired of replacing fan belts too, until I figured out that the factory tensioner was no good. One person told me he heard that it was something to do with the carbon canister. Anyone have any knowledge of this?
Oh yeah, I swear it runs better than new. When I test drove it back at 35 miles, I stalled it backing up every time, even though I have driven a standard all of my life. I've stalled it backing up for 22 years until now. I can back up with impunity now, no stalling. As a guess, I'd say that was the throttle position sensor. It didn't ohm out real good. Truck runs so smooth now, I can't hear the engine from inside the truck.
I hope that in all of this there is something that might help someone out of a jam. We can't all be Einsteins of car mechanics, so sharing does help (like the guy with 118 helped me).