Hello again. Still having my usual problems, and still coming to you for your usually good advice.

Dad's F-150 is still doggy. Actually, its gotten worse now because the gas milage I guess has gone right down the toilet. Was 15-16, now its 10-12. And he says it has another problem where it now acts doggy all the time. I've been researching some posts on here and found one by a member, poffutt, who said this of his 89 Bronco:

When you are driving at any speed 20 or 50... when you press the gas to go a little faster, it feels like she wants to bog down untill you press the peddle to the floor. At a stop sign, if you bearly press the gas she runs good, if you start pressing the gas more, then she starts bogging down... it feels like she is fighting herself until you floor it.

That's pretty much how Dad says his truck runs, and its a 94 F-150 with a 302. We pulled the codes on it, and got a 212 about the spout signal being not grounded. We did some testing per the Haynes Manual instructions and determined the ICM needed to be replaced. After replacing it, we cleared the codes and drove it, and when we pulled the codes again, 212 reared its ugly little head. So we've been testing this and testing that, going down one dead end road after another.

So right now we're here with no clue what to do next, and we're wondering if anyone can give us some advice on something else to look for. Once again its a 1994 F-150, 5.0L V8, 4R70W 4 speed automatic transmission. 4x2

Any and all advice is appreciated. Thank you for your time, and have a great rest of your weekend!

 

I looked that code up in my '95 factory manual, and it goes through a long series of wiring checks with the PCM and ICM unhooked. But basically all it's saying is the problem is either a short or open in the wiring, a bad ICM, or bad PCM (not likely). Did you put an aftermarket ICM on it? I haven't had too good of luck with some of them. Otherwise, I'd check all of the ICM wiring. Good luck, I know it can be a pain tracing wires.

 

if you know anyone with a snap on scanner, or other high end scaner, you can do the wiggle test, and see if somtins goin on with a loose connection.

 

We have installed a new ICM from Autozone and tested it and it appears good. We've tested a few other things too and the only thing we've noticed is the resistance of the ignition circuit to ground was something like 7700 ohms instead of 10,000 as the book says. Would that be enough to cause a problem?

Another thing we noticed was when testing the PIP sensor, it told us on pin 8 we should be reading the battery voltage at all times. But when we test it, if we're getting a good connection it says 0 Volts. This pin also connects to nothing inside the other half of the connector.

I dunno what's going on. There's too many wires under the hood of that thing, but I think I've told you everything we've managed to find out at the moment. If this helps anyone, please feel free to comment. Thanks!

 

Well if it helps anyone, the other night I took off the ground wires for the ignition (i think) at the radiator support and cleaned them thoroughly. It didn't help any, but we did notice afterwards that the truck runs good while its cold. When it gets warmed up is when it starts running badly. I'm guessing this is because is running a preset condition in the computer until it senses the engine's warm enough. Then it starts playing with settings and screwing stuff up. Is this a valid assumption?

 

i would lean towards o2 sensor, as when the engine is in its cold loop, it runs a richer condition to warm it up, then when it warms up, or runs a certain amount of time, it kicks into open loop, lettin the sensors determine the runnin conditions.

 

Even though we're still getting a code 212 message?

This is after testing and replacing the ICM, and checking some other wiring only to have everything else fall within specs.

 

Hey, just to let you know I checked out everything that you said, the fuel pressure regulator. And I also checked the temp sensor. They checked out fine. What I did find out was a much simpler issue, which is actually a little embarrasing. The MAF was really dirty, because the PCV valve was'nt doing its job. So i pulled out the throttle body and it looked as if its never been cleaned since it was bought. I had to scrape crap off of it. I recently bought this truck from someone, so dont look at me heh. But anyway when its all said and done the biggest reason my truck ran so bad was because the PCV valve needed replacing, MAF cleaned, and the throttle body cleaned. Now it runs like a champ. Thanks for your help guys.