Well thats about it... It runs good from about 2200-4500 RPMs. Freaking screams in that RPM section. Under that, ha, forget about it. It will pop and crack and sound like its losing fuel or spark, but its not. Fuel pressure stays at 38 psi at idle and about 40 with throttle. Spark curve advances with throttle. Refer to: https://www.ford-trucks.com/forums/9...arn-thing.html for a little background info on what has been done.

The idle quality is pretty bad, will stall sometimes and sounds like a BIG cam is in there... I replaced the Ignition module and it ran beautifully all the way back to my house from my buddies. About a 10 min ride. Then she was back to the way it was before. I replaced all my grounds and replaced and double checked all vac lines. The sensors are all new in the lower intake. Nothing has been changed in the plenum (IAC, TPS, etc) because nothing was throwing codes. Any ideas on what my be wrong?

 

I saw in the other thread that you replaced the TFI module, and you saw somewhat better results. Did you coat the back of the module with heat sink paste before installing? Are all the screws that hold the module on there and tight?

 

yeah i used the heat paste amnd the screws are nice and tight. Snugged them up by hand and then a 1/4 turn with the wrench...

 

Well i guess im on my own with this one... Thanks to anyone who has posted in this thread and my other.

 

I wish I had more ideas.... I had a Crown Vic once that would eat through TFI's like Whitney Houston at a crack buffet. Same symptoms as you're having too...

 

I've been following your troubles, I just don't have anything to offer, unfortunately.

 

Yeah I would love to offer you some help, but I just dont know either man.

 

So you changed the distributor and the motor acted differently? Before it wouldn't rev and now it does but pops and backfires at low rpms right? Was this a brand new Ford distributor, a parts store piece, or something else. FWIW the aftermarket ignition products are crap.. the TFI modules in particular, so you could still have a bad PIP or TFI module.

 

Well thanks guys. I just didn't think anyone was reading up on it. Its been rough. I was almost thinking of swapping to a carb, but if i'm having trouble with the EFI i'll most likely have troubles with the carb too...

 

Finally got a code for the PIP. Went to advanced and got a new distributor and put it in. Used my old ignition module and it ran better, but not as it should. Idle quality isn't what it should be and will now rev past the point where it used to choke and make good (not great) power up top. When I changed to the new ignition module it ran beautifully... for the drive home. Ran great warm, down shifting and passing cars was a breeze. Got home, shut her down, went to leave again and back to the same symptoms.

EDIT: i took the ignition module off and had Advance Auto check it and everything came out on the good side of things...

 

My TFI's always checked good too, which made warranty replacement tough. It seemed mine only failed when they were hot.

 

maybe ill try driving around awhile and take it off right at the parts store and have them test it while its hot. Wouldn't be too hard, but they may not want to handle it from being too hot.

 

Do you have a Ford TFI module? If not go to the scrapyard and grab a few, you need the grey module too not the black one.

 

Im not sure if there are any yards with anything older than 95 around here. Which is a bummer becasue there used to be a bunch of these era trucks around. I may know of one yard with a few and i will check there soon.

 

would the TFI affect the idle quality at all? i'm not getting any codes at the moment, but its running at idle like there is a big cam in there. Lopin and whatnot. Could I have a bad IAC without it throwing a code for it?