If the truck is truly misfiring, the fuel filter is probably not the issue. It could be an injector issue, it could be a plug wire that is not seated quite correctly, it could be a vacuum issue from the intake manifold gaskets, it could be a MAF/MAP sensor, it could be a compression issue, etc.

Does the exhaust look dark or smell rich?

-Rod

 

Reset the KAM today and for the most part it has worked. Initial cold idle decreases as it should. Since I reset the memory, I now have been driving easier to reset the proper shift points, as those reset as well. Coming to a stop, the engine slows as it should and doesn't jerk, and it doesn't high idle while going through a parking lot. Now the only part I'm dealing with now is, after I shut it off for a moment to 30 minutes, with the engine still warm, it still has the 2,000-2,500rpm high idle. I'll have to spray the hell out of the butterfly valve and check the it while it starts up after being at operating temps.

So far it's good. Hope to see mpgs get back to normal. And hope to get the hot start idle to a lot lower rpm.

 

I did do sea-foam thru vaccum line.It did improve but still cuts out lower rpm's Better but not 100%

 

Running sea-foam thru the vaccum line helped but not 100%.I need to replace the vaccum surge line 9/20/16 waiting for the part.I plugged off the lines until my part comes.

 

So I'm starting to wonder if part of the idling issues now are caused by running the A/C compressor a lot. Because having it off, engine idles just fine, but having it on makes it run a lot higher and it doesn't like to drop to a lower rpm easier when coming to a stop. Been trying to have the control module re-learn everything, but my old lady can't seem to live without the dang A/C when its 60 freakin degrees out side. Makes it harder for it to re-learn everything with A/C running all the dang time.

 

Having the A/C on shouldn't effect any "relearn" procedures. The PCM knows what's on and what's not. But, it's interesting that you have noticed the idle correlation with the A/C on. The Idle Air Control (IAC) motor is supposed to increase the engine idle to account for increased loads such as the A/C being on or the power steering being at one of the locks. Since the idle speed seems fine with the A/C off, I'd suggest focusing your efforts on the IAC area. Maybe the throttle plate is not closing correct at idle and the IAC is allowing too much air past it. Or maybe the IAC is not the correct one for the vehicle. Possibly someone adjusted the throttle plate to "fix" a low idle issue years ago and now that things are mostly fixed, the idle is too high.

-Rod

 

That's always a possibility. I mean it was completely fine when I reset the KAM, but a day later it was back to its old self with high idling. It's apparent with A/C on for sure, but now it's doing it with it off too. Getting frustrating for sure now. I'll have to check the throttle plate more and see what's going on, maybe have someone step on the gas and release it, while I'm under the hood, and see if the butterfly valve closes. Right now I'm in no position to buy a new IAC, other wise I'd get a Ford part to see if that fixes it.