HeavyArms SS

iTrader: (4)

I'm having issues with the cold start idle on my '99 Z28. When I first start it up it wants to die, the rpms fall really low and then I have to give it some gas just to keep it from stalling out. After a couple minutes of letting the car run it will settle it's idle in at 850 which is where it's supposed to be. It does not idle low at any other time.

The engine specs are: PRC Stage 2.5 5.3L CNC Ported Heads, Prc .650 dual springs, TSP Magic Stick 3 237/242 .603"/.609", 36# Precision Flow Injectors, LS6 Intake, BBK 85mm Throttle Body, SLP 85mm MAF & harness, LS7 Lifters, Chromoly Pushrods, LS6 Oil Pump, LS2 Timing Chain, !EGR, !AIR, SLP lid, and Pacesetter longtubes.

The car was dyno tuned by the previous owner at a shop in California. I cleaned the throttle body and IAC(which were pretty dirty) and it still idles bad on cold starts. I don't have a handheld tuner to get any readings from the engine. I took a video at cold start. Any suggestions? Thanks.

http://www.youtube.com/watch?v=ylhoq...ature=youtu.be

HeavyArms SS

iTrader: (4)

Any ideas? I have a new IAC on the way and should have that next week.

Old Geezer

iTrader: (3)

A suggestion: With an engine w/ as many mods as you have......Buy a scan tool.
Or, find someone local that can scan and data log a cold start. Post the log[s], and the tune.
Otherwise, it's a guessing game.

MillsMotorvation

Got to get something to scan or tune with

HeavyArms SS

iTrader: (4)

I replaced the IAC since the one that was in there was pretty sad looking and the o-ring was mostly deteriorated. I also replaced the SLP 85mm MAF with a stock one and it is a thousand times better. I guess the SLP unit just went bad.