IAC VALVE on J

[alex61089]

Hey guys i just wanted to ask this question before i rip this engine apart to get to the IAC Valve. If the IAC Valve is malfunctioning can it cause driveability issues? Sometimes when i start up the car the engine starts to stall out then goes up to standard rpms and afterwords when im at lights for a prolonged period of time the rpms start jumping and sometimes i stall out, if i go to give it gas while this is happening i get bad hesitation and jerking almost like the engine is trying to run but is being starved?

[GerryO]

My story:

I pulled the plenum off of my 1993 J30t at about 170K miles, after the first fuel injector failed.

At the same time I replaced all six injectors, spark plugs, both PCV valves, O2 sensors and the EGR valve. Both EGR tubes were very clogged where they attach to the underside of the plenum. I cleaned the throttle bodies, MAF and flushed a lot of carburetor cleaner through the plenum with the IAC valve assembly still attached, and wish I had known about removing and disassembling it to clean it.

Part of the reason I didn't remove it was because I removed the throttle body heating tubing and hoses, and I didn't want to disturb too many things at one time. Now I want to remove the IAC valve to do the disassembly/cleaning and need to install a length of metal tubing to properly heat the AAC valve to drop the idle while the engine warms up, and other than when the car is totally stopped.

Pulling the plenum will be a lot easier next time, with no coolant hoses to disconnect, and a pile of potential leaky connections are eliminated.

Other than that the engine runs great. There's a lot of good that you can do with the right tools, a minimal number of new parts, and taking the time to simply remove, thoroughly clean and carefully re-install any number of parts.

I can't imagine something along the lines of a SeaFoam treatment being and doing as much good for an engine.

What does the trouble-shooting and diagnosis section of the FSM have to say?

[alex61089]

Man i cant stop laughing.... I was thinking about when all my problems started and i realized, my AT light never came on nor did my car have stalling problems until i changed one thing on my car. That "remanufactured" mass air flow from napa. And guess what. My mass air flow was never bad ( the original one of course ) so i put it back into my car and yay! it doesnt stall no more or anything. So i think we can learn a lesson from this, dont buy a remanufactured MAF from napa because... well it sucks.

[yodawill2000]

Good news !!

[GerryO]

Man i cant stop laughing.... I was thinking about when all my problems started and i realized, my AT light never came on nor did my car have stalling problems until i changed one thing on my car. That "remanufactured" mass air flow from napa. And guess what. My mass air flow was never bad ( the original one of course ) so i put it back into my car and yay! it doesnt stall no more or anything. So i think we can learn a lesson from this, dont buy a remanufactured MAF from napa because... well it sucks.

Good catch! Another priceless nugget added to the knowledge base, along with very carefully examing all of the advice that you receive (and offer) on this forum.