Replaced IAC, is this normal ?
03-17-2012, 06:22 PM
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Replaced IAC, is this normal ? I replaced my IAC today, did the idle relearn but when i start the car the idle goes higher than it normally does then drops back down. With the original IAC it never went that high when the car is started. Overall the idle is better than before, just concerned about how high it goes when first started.
http://www.youtube.com/watch?v=BCBn_N7Nt6Y
http://www.youtube.com/watch?v=BCBn_N7Nt6Y
03-17-2012, 09:17 PM
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That is not normal, it should not rev to 2k rpm even on a cold start.
If this started with the IAC replacement, then I would start by checking over everything touched during that repair. Check for vacuum leaks around the IAC (gasket [O-ring] missing or damaged, screws loose, etc.). Did you touch anything else during the repair (TPS, etc.)?
Maybe you just got a bad IAC.
If this started with the IAC replacement, then I would start by checking over everything touched during that repair. Check for vacuum leaks around the IAC (gasket [O-ring] missing or damaged, screws loose, etc.). Did you touch anything else during the repair (TPS, etc.)?
Maybe you just got a bad IAC.
03-17-2012, 09:30 PM
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Its even worse on a cold start. I put the original IAC back in and it started normally. Checked the o-ring and it looked ok. I guess its a bad part.
http://www.youtube.com/watch?v=v9esYBrsmfQ
http://www.youtube.com/watch?v=v9esYBrsmfQ
03-20-2012, 07:50 PM
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I've had something similar happening on my LT1. I have always wondered if it is a bad IAC valve. It seems like on my LT1 if the blade set screw is wound out pretty far it would always do this but seemed to be better if I backed it out a bit. Is the LT and LS IAC the same part number?
03-20-2012, 09:47 PM
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I've replaced the IAC on one of these before, and nothing had to be set before hand. If it's an OEM IAC motor, all you have to do with these cars is install it right out of the Delco box. Not sure what the situation might be with an aftermarket IAC though.
