What is it? Whats it function?
My car is misfiring, I think it may be related? How can I test it and whats the easiest way to remove it? Remove the TB?
Can it be cleaned or does it need to be replaced? How much does the part cost?
Thanks guys..


edit: I repalced my head gasket and now my car is misfiring. I am pretty sure the opti stayed dry... I drained the system FIRST and then I kept it clean when I pulled the heads off. I just finished installing a new opti a month ago. While the intake was off I took out the IAC and cleaned it. Well all done and said the car was fixed but returned with a monster misfire/lag throughout all the rpms. Car idles a little high occasionally. I am waiting for parts to come in... injectors, O2s, and MSD6A.

 

I am quoting from the Chilton's Manual for the definition....

IAC (Idle Air Control) Valve

Engine idle speeds are controlled by the PCM through the IAC valve. The PCM sends voltage pulses to the motor windings (of the IAC) causing the IAC motor shaft and pintle to move in or out a given distance (number of steps) for each pulse. the movement of the pintle controls the airflowaround the throttle plate which in turn, controls engine idle speed.

Here are a couple links from Shoebox's site which is awesome to say the least.

http://shbox.com/1/iac2.jpg

http://shbox.com/1/4th_gen_tech2.html#iac_reset

 

IAC shouldn't cause a dead miss.It controls the idle speed by regulating the amount of air going into the engine.
I would look at plugs,wires,valve adjustment,ect.

 

Valve adjustment?

 

Not a techy by a long shot, but when someone says they have a "mis fire" I'm thinking that they are missing a fire, i.e., either the timing is off or the cyl (s) are not firing because of an ignition problem, e.g. broken plug, bad wire connection, etc.

Until you can rule the electrical part out, I wouldn't speculate on what else might be the problem.

I' m guessing that an electrial diagnoisis is in order, unless you are getting codes denoting the problem.

Also, a quick check to see if your bellows is correctly fitted to your TB is one way to make sure you don't have any problems with the intake air.

Narrow it down starting with the easiest to check before you blame it on the opti. And yes. Make sure it's not a valve adjustment problem. JMHO

 

Yeah, I replaced the opti, coil, wires, plugs, fuel filter and today installed an MSD6A. Still there! I did get my injectors in the mail today.. ill put them on tomorrow. So I'm just trying to rule everything on the list out. I just cant think of what else it could be?
Whats a valve adjustment?

 

When the head work was done ya have to adjust the valves.Soooo it needs to be rechecked before ya run your bank account dry throwing parts at it and hoping they will fix it.
If the injectors aren't stock ya will need a computer tune.

 

I am betting on the wires.Open the hood at night with the engine running,check for arcing.

 

He just replaced the wires again. LOL I'd like to see what setting the valve lash does. Do you know how to set the lash with the motor running? Are these roller rockers?

 

Oh damn, you mean I have to torqe to rockers down a certain way? All I did was tighten them.. I dont know how to adjust them. Than can cause a misfire??

 

Dam Skippie

Go to Shoebox's site for the procedure.

 

http://members.***.net/95lt1/helpme!.jpg
talking about the same thing, right?

 

Yeeeeeaa
Go to Shoebox's site and get the procedure.They should be no more than 1/2 turn down.Back off untill clacking steady then tighten slowly until no clack then 1/2 turn tighter done slow. This is with the engine running(it's messy).Don't try the rotation of the pushrod method it takes practice.