Hey List,

i have a 92 f150 4x4 302 5 spd.....

the truck is beginning to develop a serious idle /stalling issue.....

first the symptoms....

start up..fine...idles fine for a while...then i hear a click, like a relay going off or something ..and the idle starts undualting anywhere from like 100 or 200 rpm all the way up to 1000.....hit the gas seems to fix it..but then wait a few minutes, hear the click, and the idle goes all to hell again....recently, the idle wont hold and it will just stall...

the above is all at idle, not moving or driving...in neutral....

when driving and decelerating , no gas...coasting now the rpms donb stiop at an idle speed itll just kjeep going down until it stalls or i catch it and gfive it a shot of gas....it seems to do this at least twice in a normal morning commute..(maybe 10 15 minutes....)..doesnt seem to matter whether shes warmed up or not.....

mods to the truck....
no airpump or cats or emmsiions anymore...true dual exhaust....

recent stuff ive done...

complete tune up..new cap rotor plugs wires aircleaner oil change tranny fluid change..and i even cleaned out the throttle body....

all of this seems to make no difference....

any help would be greatly appreciated....

cheers,

Paul

 

Check out the IAC valve on the throttle body. It gets gummed up and doesn't allow the engine to idle correctly. If that's not it, I would start by pulling the code.

What truck and motor are we talking about?

 

heh, as on the top of my first post..its a 92 302 4x4...

whats the iac look like?
sorry for the simple question, but its my 1st time doing any work on my 302

 

Whoops! Sorry.

It's a small thing, about 2 inches long maybe. It has two wires coming out of it, and it sits right on the throttle body.

 

so is the IAC a cleanable item (if so how?) or does it have to be replaced?


Thanks

Paul

 

It is cleanable (or so I've been told) but I cleaned mine and it didn't help my idle problem. I used some Carb. cleaner on it but ended up replacing it. I paid $43 for one at O'Reilly's.

 

did replacing it help??

 

I have an 88 f250 351 which had a similar idle problem. I went to autozone and had them check my engine codes. The code 23 which came up was the throttle position sensor. Cost me 30 bucks and solved the problem. Sensor is located under the throttle body and has 3 wires. Had to take the throttle body off the engine to replace sensor.

 

The problem I was having was, every now and then the truck just would not idle. It would run fine just not idle. It has not done it since replacing the IAC about 3 weeks ago. I'm hopeful it is fixed but not 100% convinced yet, maybe in a couple more weeks I'll be convinced. Oh, this is a 96 with a 5.0.