lifted90f150

Ok so I have an idle problem. It's fine till the truck has warmed up the it isles like the tps sensor is bad. If you unplug the tps or iac it doesn't make a difference so I don't think either are the problem. It's a 1990 f150 with a 302 I put an Elgin cam that has a lift of .498 and duration of .282 went from truck firing order to h.o. firing order also has e5 heads ported intake a throttle body spacer and gear drive timing setup, roller rockers and msd street fire coil. Idk I'm stumped on what it could be. Runs really rich. And suggestions would be great.

markes12344

just a thought... have you tried disconnecting the IAC valve, then either zip tieing the throttle body open a touch, or adjusting the stopper screw to have the extra bit of air go right past the throttle flaps. thus mimicking the job of the IAC valve and seeing if the truck idles as it would after the truck warms up and the IAC valve usually would close off more, but in your case may be closing off completely.

I know you said you disconnected the IAC valve, yet this only creates the issue of the truck having no air intake.

DerrielsFlareSide

I have a 1992Ford F150 FlareSide with a 5.0liter into it,I was driving it down the road, it just stop running.. I need some help with this Lil problems. Plzs help me out with this Lil problem ,and thaxs very much ppls.

markes12344

Okay big vast away to cover there.... so you say she just stops eh... hmm. distributor cap has a piece of electronic in it. if that cord gets unplugged or the electronic malfunctions the truck will just stop.

Give us so more details about the truck, did you pull some codes at all?

lifted90f150

Ok I could try that. I'm not sure how far open it needs to be at idle. Any ideas? Could that be causing it to run rich also?

Forge-World-FORD

Don't thread jack. Start you're own thread if you need help.

markes12344

Only thing to do really is open it a little bit then adjust once truck is running, go by ear if you don't have a tac gauge. simulate the job of what the IAC valve should be doing.

The truck could be rich from lack of gas yes, but the truck should be able to realize to much fuel needs more air and cut back the fuel. maybe the computer needs to run both IAC valv and injectors, and if the IAC valve is pooched that is where the rich is coming from.
The other possibility is the injectors could be starting to go. i know when mine where done the engine burned hotter, and a few cylinders burned lean with not enough fuel while others burned rich with too much fuel, and some burned just right all in all the computer can only compensate for so much.

Lets just start with the IAC valve test see if you cant get it to idle smoother.

lifted90f150

Well I noticed it took like a quarter of a turn to get the butterflies to open so I thought if maybe I just barely adjust that idle screw which I did it would idle ok and it does and the butterflies didn't move

markes12344

well so it appears you should attend to the IAC valve or TPS remember to buy motorcraft when it comes to the IAC Valve, that is if you can not clean the IAC.

techrep

iTrader: (1)

WOW...just jacked the thread