I need to raise the idle rpm up about 100 revs. Can this be done mechanically, or is it an electronic fix on this engine. Sorry I'm not familiar with this engine. It's in my sons GMC 2500. It runs fine, just idling too low ('bout 500 rpm) and there are times it acts as if it might stall. Thanks.
Has this all of a sudden happened, or has it been biulding up. The idle needs to be adjusted by computer (any dealership can do it), or if you are confident, I think a very,very,very small hole can be drilled in the TB plate. Clean the filter, TB, and MAF sensor. Check out www.performancetrucks.net for any info regarding these motors.
No! No! No! Don't go drilling any holes or reprogramming of the computer. The idle speed is programmed into the computer and it is supposed to be higher than the 500 RPMs you are experiencing. Instead of jury rigging it by drilling holes, or whatever, fix it. Chances are the TB needs to be cleaned, especially the IAC passages, and the IAC solenoid itself. The procedure ought to very similar for any EFI Chevy.
Sorry if i was miss-leading you, the drilling of the TB should be done as a last resort, I know that some poeple do it if they are running a bigger cam and cant get a idle tune to work them. Just for curiousity, what year truck is it?
An engine with too large a cam never idles too slowly. So this wasn't the OP's problem. Drilling the throttle plates is a misguided cure left over from the carb days. When the tuner couldn't figure out a better way of admitting more air into the engine to get it to idle, holes would be drilled in the throttle plates to let the air in, without having to leave the throttle plates so far open, the idle transfer slots were exposed. This ruins the transition from idle and hurts drivability. Our TBs don't have idle transfer slots. Drilling the throttle plates isn't necessary on either a carb or a TB, but there never was an excuse on the TB.
Corvette Store
2003 GMC 6 litre truck engine
My '02 did the same thing, would sometimes stall on tight low speed turns. Just clean it out as posted above and all will be well.
