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IAC Prck oblem's

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  #1  
Old 08-18-2011 | 11:49 PM
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Default IAC Prck oblem's

So just picked up a 02 1500 2wd for $1k, good deal it needed a fuel pump and a few other cosmetics. To be honest I am a born a raised Mopar and cummins guy. This is my first bowtie and was bought for the purpose of being a daily driver back and forth to college and pulling my drag car on the weekends.

After replacing the fuel pump everything went good for a few days. Now when the truck is cold it starts right up. After it gets warm and try to restart it starts like it should rpm jumps up then dies. A few tries later and some pedal massaging its fine. Seems the IAC is sticking shut after its hot and shut off. Anyone else have or heard of IAC troubles? No codes but it is a stepper IAC so I don't think that it will throw a code if its not working.

I did have a MAF code and converter under efficiency code. Cleaned the MAF and cleared codes and it hasn't come back, although it does smell as if it is running rich.

Thanks
 
  #2  
Old 08-19-2011 | 10:43 AM
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Iac issues are fairly common and an inexpensive fix. Replace and forget about it. You shouldnt have many issues after that.

Welcome to the boards btw.
 
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Old 08-19-2011 | 04:29 PM
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Oh just never heard of anyone having IAC problems. Am I correct that since it is a stepper motor IAC there will be no code thrown. <Very novice on Chevrolet ECU systems.
 
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Old 08-19-2011 | 06:03 PM
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It will throw a code eventually but your original thought about it causing mass frustration and hair pulling was dead on lol
 
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Old 08-20-2011 | 12:41 AM
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Yeah stopped today and picked up a new one, seems to have fixed the problem.
 
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Old 08-21-2011 | 06:26 PM
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Ok so little update. Installed new IAC that partially fixed the problem, or at least changed the symptoms. Now it seemingly only does this when it sits overnight or for a long period of time. Just took the fuel regulator apart and cleaned. Going to have to pick up a rail pressure gauge and monitor pressure. I am starting to lean towards the new fuel pump not being able to build pressure consistently.
 
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Old 08-21-2011 | 06:48 PM
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maybe ur throttle body is dirty an debris it clogging the new vavle
 
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Old 08-21-2011 | 07:49 PM
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It's a good possibility unfortunately. It sucks when one fix shows another problem but that always seems to be the way it goes. Hopefully you get it fixed and if you do have to replace the pump, pulling the bed is easier than dropping the tank.
 
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Old 08-22-2011 | 07:40 PM
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Forgot to mention I did clean the TB and old IAC valve before replacing it. I ordered another fuel pump, original AC delco instead of parts store.

Yeah dropped the tank the first time cause I didn't have anyone to help move the bed. Not the worst one I have done but its up there. Will be pulling the bed this time.
 
  #10  
Old 08-23-2011 | 03:17 PM
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If its running rich and RPM's go up and down, then it is a vacum leak. Computer sensing a lean mixture cuz of the vacum leak and pouring more fuel to compensate. Replace intake gaskets as this is very common. Also TB gasket and everything that has to do with vacum I would check.
 



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