My truck has this werid surging idle issue. It seems to be doing it a lot more lately when I start it up. It will go up to like 2 grand then drop down and surg back up and will keep doing it. Sometimes hitting the gas calms it down a little. Any idea on what would cause this?

 

your IAC is most likely on it's way out. it's supposed to control the idle speed and if the motor is not responding, it'll idle funny.

 

is this on start up or all the time??

 

it does it sometimes a while after start up its not just at startup if that makes any sense

 

yeah it does... your IAC valve is going bad. it's on the back of the throttle body. swap it out and you should be good to go.

 

whats one of them suckers run?

 

Probably is the IAC but ................... has anyone been working topside under the hood recently? If the air filter housing isn't seated and clamped properly to the TB air will enter at that joint and cause the same symptoms. Had the same problem, FIXED.

 

umm not for a while but I will check it out. I found on advance's site and IAC is like 50 bucks not bad I guess. How hard is it to change out? And does it hurt anything having a bad one?

 

Don't want to offend here but I wouldn't buy anything $$ at Advance. Went through 4 rebuilt carbs before getting one that lasted, 3 wheel bearing assemblies on my s-10 blazer, 2 sensors on my old s-10 PU. Batteries were a good value tho. If it's out on the shelves np, but anything else think twice. It's less expensive for a reason. Hurt? Why don't ALL vehicles rev at idle?

 

I have been buying stuff at advance for a long time and never had any problems. So I guess that means I should change it