I am about at my wits end. I put a re-manufactured 5.2 with a Comp cam and springs and double row timing in my truck. Also headers, Magna flow cat back, Holley throttle body. I didn't like the performance and ended up buying an SCT tuner with a custom tune from P.I.E. in Delaware. I put in the tune and the performance improved but the engine would stall on quick stops with the clutch in. I called the tuner and he advised me to drill a 3/16 hole in the rear of each of the butterflies. He told me not to touch the adjustment on the T.B. as this would affect the throttle position sensor. The truck ran and performed well for awhile, then the idle seemed like the throttle was sticking and took several seconds to drop to normal. Now the idle will go to over 2k for up to ten seconds and the engine is popping and spiting. It's like the computer has gone crazy. I feel like I should go to a carburetor setup and bypass the computer. Can anyone help?

 

There problem is your tune P.I.E suck

 

I hope you didn't ruin your blades and drill them? You need to adjust your blades, and pay the money for a better tuner.

 

Thank's for the reply: Well.... I did, I can weld them up if need be. It ran well after drilling them but after a week or so the high idle issue showed up. I am going to get another quality TB gasket tomorrow and see. It sure seems like a vacuum leak to me.

 

It's the tune.

 

Unplug IAC with plunger out, set idle by adjusting throttle blade. Then get new tuner.

 

Thank you very much! I plugged the holes in the blades and will give it a try tomorrow.