Hi all,

So it's been a war with this truck. For those of you that don't already know, I bought a 1995 F-150 supercab 5.0L 5 speed 1wd. When I first got it, it ran pretty bad and had a bad case of the shakes. After pulling my codes (long list), I have replaced the MAP, IAC, cap and rotor, plugs, wires, fuel pressure regulator, fuel filter, two oil changes, 3 seafoams, built my own intake, re-did the exhaust with a magnaflow, and did the clutch. It's running pretty good now and has much more power than it did. My only main problem now it it still has the shakes every-once in a while at random. The engine light started to come on here and there just for a brief second and shut-off, it also came on when I took the truck over 4000rpm but turned off as soon as I brought it back down again. So last night I put a new 02 sensor seeing how the old one looked horrible and it still said Ford on it, not too mention it was pure white and looked in bad shape once I pulled it. So I go to start the truck up and voila, it idles perfect with no rev hang and even sounded better. I took it up to Timmy's for a coffee and came back and it ran so much better the whole time. So this morning I drive it in to work and for the first 25min it had some of the shakes again and the engine light stayed on the entire time. For the last 15 min of my drive it seemed to get better and better as i drove it. Sorry for the essay just wanted to cover everything I could think of. My question now is if I put a non OEM O2 sensor in would it trip the light? Also, what are the symptoms of a bad TPS?

 

Don't disconnect the neg. battery cable yet...

Nothing wrong with a Non-OEM sensor. I use Bosch for the most part. 99% of them run fine. I've heard some have had problems, but it's usually something further up the stream of parts.

TPS can several different problems, from high idle, to stalling. Here's the link for the diagnosis. https://www.ford-trucks.com/forums/1...e-problem.html

There's been more recent talk of PCM failure on this forum. I rarely suggest checking this, but may want to give it a shot. If there is any capacitor problems on the board, this could be some of your headaches. It may be worth looking into.

Only other thought about the problem, was whether or not you disconnected the negative battery cable for at least 20 mins after installing the new 02 sensor. IF not, the PCM is still using corrupted strategies to try and smoothly run. I would pull codes once again to see what the flicker of the light was pointing to. It may be as simple as clearing the PCM memory and letting it learn new strategies.

Let us know what happens.

 

Is there a check I can do fir the pcm or should I just get a new one? I was thinking of grabbing a tps just so I can say it's new. I did reset the battery but only after a I got to work this morning and haven't driven it yet. The only other thing I can think of is injectors, I have checked all vacuum lines and all are well except for one that goes to big bowl thing to the left of the throttle body but I just unplugged it and it didn't change anything. I have also done a compression check and to my surprise it was all pretty flat across the board which is pretty good for a truck with 224k on it. Ohh I haven't checked the timing yet which I guess I should do. I'm just afraid to see broken teeth on the stupid nylon sprockets.

 

No nylon gears that I know of on the 5.0. To check the PCM, you will have to remove it, and visually inspect the PCB board.

 

Got it rescanned on my way home from work and was getting a egr failing to open/close and engine balance failure. The green vacuum line that went to the egr valve was cracked near the black 90 rubber piece so I fixed that and my egr problem is gone. Now I'm a little confused on the engine balance failure. I had good level compression when I tested it two months ago, I have replaced all ignition related parts, and the common fuel culprits. The only two things I can think of would be a bad injector/injectors, or another vacuum leak that I can't find. Any other sugestions as far as areas I may have overlooked?