Need a little help. I just installed my LS1 into my car. Can't get it to idle. I am using a S&P pcm that was flashed for my specs. It runs great at about 1200 rpm's but after it warms up it wants to start surging from 1200 to 1800 and will not idle. I have checked for vacum and it shows 20. Have 60 psi fuel. No codes in the pcm at all. Just wont idle. I did put a small gm LS1 hot cam in the engine when I put it together. Can't figure it out......Help..

 

Heh...it may be small, but to quote some: "it chops". Can you post a picture of what you slapped together? It is hard to get a good image based on that. If you have Autotap, I would see if it is throwing codes, and monitor some stuff. If you are using the stock throttle body you will need to turn the set screw to get it within a reasonable range so the computer can do the rest. The hot cam is a beotch to get to idle right. Mine is doing great now...but after driving on the highway it still acts odd for awhile until I drive around town for a few minutes. Is your PCM programmed for the hot cam?

 

try this
https://ls1tech.com/forums/pcm-diagnostics-tuning/177230-stop-drilling-those-tbs-fix-stalling-without-computer-tuning.html

 

Thanks I'll give it a try. I appreciate the help.............

 

Thanks guys. Figured it out. Had a bad IAC sensor. Who'd a thought. I appreciate the help.

 

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