See "Annoying engine problem" below this post for details, but I was wondering how to test an idle air control valve. The one I have is not cleanable, and I'd like to see if it's working properly before I buy a new one.



Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

You can see if your minimum air adjustment is correct by pulling the connector off the idle bypass solenoid when the engine is running. The engine rpm should drop, and then the engine will struggle and die. If it keeps running, turn the idle screw to close the butterfly valve a little. It it dies all at once, open the butterfly stop screw a little.

 

You mean just unplug it?


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

Yes, while it is running(idle). This is just a test to get the throttle valve right. You will probably get some codes from the computer too, but these can be erased by disconnecting the battery for a few seconds(engine off).

 

Ok this new thing has happened to me twice now. The last two times that it has been really cold out (about 30), the truck idles funny. After the truck hasn't been running either all day or when I go to drive it to school in the morning, I started it up and it runs ok. But this is the problem. You know how when you start the cold engine, the RPMs are held up to about 1500rpm for about a minute before the computer kicks it down to the normal idle of 700. Well mine never kicked back down even while driving. I had my foot on the brake in 1st gear and it was fighting me like I had my foot on the gas. When I reved it up to about 2500rpm to shift and pushed the clutch in and held it in (neutral) the RPMs would slowly come down to about 1800-1900 and stay there until I had to shift again. It's still a little early for me to be getting details about when/what happens because the two times it happened, i was driving to work and couldn't sit there for an hour trying to find out details like....if it goes away when the engine warms up.... if it only does it in certain driving conditions, things like that. I will try to find out more but does this sound like the Idle Air Control Valve, or something else?


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

spray carb cleaner in the valve (take it off, spray cleaner in, let set for a while, shake excess out and put back on). it got rid of my fluctuating idle on my EFI 302.

 

88grandmarquis, I would like to do this. Where is the IAC valve located?
Thanks!
Chris

 

it is mounted on the side of the throttle body. attached by 2 small bolts. there should be wire plugged in one end for the sensor. it's about 6 inches in length. what i did was take it off then took the 2 screws off and opened the top up and put the cleaner in it.

 

I'll give it a try and see what happens.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

mustang did you figure out this problem
i have the same problem with mine
my rpm stays at where it was when i started to shift
when i put the clutch in the rpm stays like a stickign throttle
if i hold the clutch in the rpm slowly comes down

 

I havn't had time. Between school and 40 hrs of work a week I can't get much done. I wanted to do my LS swap over thanksgiving but it snowed here and we've been getting very cold weather and I'm just going to let it go until I get some time and feel like going out in the cold weather to do it.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

let me know how you make out with it
ive cleaned and tested my iac tps air bypass valve plugs cap rotor fuel filter air filter pcv throttle body plenum and anything else i could think of
only thing i havnt checked is my map sensor
seems mine does the revving up thing more with the weather change

 

[updated:LAST EDITED ON 10-Dec-02 AT 02:20 AM (EST)] MustangGT221 , my truck was having alot of problems with cold starts after sitting all night, after reading suggestions on the internet I removed the idle air control valve by unplugging it and removing the two screws holding it in place, it attaches to the side of the throttle body. What I did was took carb cleaner and sprayed it in the holes of the "I.A.C.V." and let it soak for a while, then took a toothbrush and cleaned it out real good and dumped out the carbon/residue from the inside and reinstalled it.


My pickup now starts every time and idles smooth as silk, nothing to it. It took maybe an hour start to finish.





Keep on truckin' ...Mike

1995 F150 Eddie Bauer supercab
5.0 V8 w/autotrans
Diablo chip
Flowmaster 40 series SI/DO
4.10 gears w/traction lok
K&N airfilter and airbox mod

 

I have removed the sensor and cleaned it with the carb cleaner. It was pretty dirty but it didn't fix the problem. I have a non-cleanable sensor, most of it I can't clean. I got some of it cleaned but not the entire thing.

Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

well today i tried a new map sensor and thats not the problem either
its gettin frustrating now cause ive checked and tried everything and the idle still seems to stick
i have the same type of iac as you mustang
did you check the resistance on yours