sixx23

When the truck will idle, the engine will run pretty rough, and the RPM'S will increase, and decrease, almost as if somebody is messing with the pedal.. It will sound as if you are accelerating for about one second, and then go back down..This "cycle" repeats itself too...Also, when that does happen, there are points in which the truck will almost stall...Does anybody know what could be wrong?

Sorry if this was a messy post..

wde3477

Welcome to the site!

The first thing I would go after would be the Idle Air Control (IAC) solenoid. Many times, these will foul up and start causing the symptoms you describe. Carb cleaner does a pretty good job on these to get it cleaned up and the piston moving freely again. If it has failed, probably looking in the $50-$60 ballpark to replace.

sixx23

Thanks!
And, alright, thanks, Ill def. look into it.
Do you have a guide, or do you know specifically as to its location in the truck?

wde3477

Go to the throttle butterfly - the IAC will be mounted on the side, a cylinder a little larger round than a roll of quarters, with an electrical connection on the end - if things haven't changed too much between our model years. Two Phillips-head screws, and it's off.

mitchalvin

My is doing the same thing, I also got a check engine light and codes 31 and 32. When it warms up a little I will probably try and clean my IAC valve.

sixx23

Thank you very much.
My grandfather is going to look into getting the part.

aliens8mycow

31 and 32 have to do with your EVP sensor being below minimum closed voltage. That's the sensor on top of your EGR valve. (brings back nightmares from my 20 page EGR thread!)

This could be as simple as loose screws connecting it - there should be 3 screws connecting the EVP to the top of the EGR - check for tight fit.

Check for vacuum - if you don't have a vac guage, just run a length of vac line from the nipple on the EGR valve and suck on it - the valve should open as you suck. If it doesn't move, you might try removing it and cleaning with carb cleaner. A stuck EGR valve should give you code 33 though.

The EVP sensor could be bad too - or not plugged in well - check the plug for good contacts, remove the sensor and make sure the pintle moves in/out, or replace it with the SAME COLOR part for $30 or so.

sixx23

Well, my grandfather went out and bought the IAC, changed it out, and it had seemed to go away. Much to our disappointment, it came right back!



Any other suggestions?

aliens8mycow

did you reset the computer when you replaced the IAC? You'll need to disconnect the negative battery terminal for about 5 minutes.

Before you do that - have you checked for codes? I'd get those before resetting, then check again after resetting.

sixx23

Well, the downside to that, is it costs 90-100 dollars to check codes.