Wierdness after changing IAC valve... did 50Resto send me the wrong part?

007

Founding Member
Jan 29, 2002
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Hi Guys:

My 2001 GTs Idle was waving about when coming to a stop or going from neutral to drive (auto). So I ordered the 01-04 type IAC valve from 50resto and installed it.

The new piece looks slightly different from the stocker... The stock one has a weird little black plastic cap sticking up out of it, the new one does not (whats that thing?). Also the electrical connection was upside down. The clip only connects one way, so you cant get it wrong, but it clipped on the right side where the stock one clipped on the left.

So I fired her up, and she ran fine. But when I revved the motor there was a clicking sound and when I got off the gas... this tick, tick, tick, tick sound that slowed and then stopped. Knocking??

This gradually seemed to get better. I took her for a drive and it suddenly seemed to be gone. I pulled over and shifted from D to N a few times, and one time the idle dropped too low and it died. I fired it up and drove home. I cant reproduce the problem now and it doesnt die anymore. No SES.

Does the ECU have to relearn the Idle mixture or something? Or do I have the wrong IAC valve? I didnt reset the ECU during the process.

I dont know if this related, but I popped the vacuum line (that goes from the throttle body to the head) off the left head while changing the IAC. I reconnected it before finishing the job by just pushing it back into the top of the head. I couldnt really see under there well, but it looked like it pushed in the hole and didnt connect very well. I pushed pretty hard and it didnt want to go in there better?
 
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I haven't replaced mine yet, but does it need to be torque down to the plenum? Maybe that is why you hearing a "tick" sound because its not on tight enough? Does it atleast idle where it suppose to be?

IAC.gif
 
I haven't replaced mine yet, but does it need to be torque down to the plenum? Maybe that is why you hearing a "tick" sound because its not on tight enough? Does it atleast idle where it suppose to be?

IAC.gif

I dont think so because the sound went away. I tightened the bolts pretty good. Re-used the original gasket though.

Idles in the right spot. Things seem better, it just wierd the way it happened and that the part itself was different. I dont know what the black cap sticking out of the top of the stock one was? Its the thing that sticks upward in your drawing. The new one doesnt have it?

D
 
I read it on here a long time ago what it was for but I do not recall. But, yeah when you reset the battery it relearns everything so I guess since you didn't reset like you said, the computer learned the hard way? maybe.