Hi guys, had a problem and solved it- just wanted to post up the experience in case someone else gets the same thing.

96 F150, 302 4r70w 4X4, 130K. Tuesday afternoon, out on the road, she shot me a code. Ran just like always. When I went to leave, started and ran fine, code gone.

Went to leave work Thursday night, and she stumbled BAD off idle. When I drove in, there was no trace of this, it came on like flipping a switch. Never died, but it sounded like it would every time. Good power on the other side of the stumble, and if I went from idle to full mash throttle, it either didn't happen, or was so short it was unnoticable. Didn't think it was a fuel pump, but I switched tanks to verify, and it followed to the other tank.

I'm thinking TPS, but there was no code at all, so I didn't want to start making 50 dollar guesses. Got out this morning, and got to checking my vacuum hoses. I found a bad hose leading to the throttle body, and replaced it.

The problem was still there. I checked for other vac leaks, and found none. I pulled the hose off of the booster, and squirted a little carb cleaner into the hose. I repeated this several times, and the problem went away.

Obviously, It's time for another round of Seafoam (It's been a few months).

I'm mostly posting this so that someone else having the same problem can possibly save time and money from my experience.

My only question is: Does anyone have any ideas as to what was dirty that the carb cleaner took care of? I can't imagine it being an injector, since it's a multiport setup. I'm just curious at this point, as baby is running right again.

 

I am having same problen w/ my 91 I-6, I sprayed B-12 everywhere I could. throttle body, booster line, vaccum manifold, IAT. Did not help much. Maybe mine is just to dirty and clogged intake is pretty nasty.