Hot Start up Stumble/surging... SOLVED !!!!


Active Member
Jul 28, 2003
Riverside, CA
Ok Let me say, OMG AMAZING AMAZING. Now thats out of the way, I've finally chased down a very random surging idle problem.


Hot Start Idle surge + dying.
- Once the car actually got moving the issue would go away
- Car had no issue on cold starts , or after the car had "cooled down" for 30 mins or more.

My first inclination was to chase down the usual suspects
-Vacuum leaks

I had narrowed it down in my mind to this
- Either a electrical issue that only showed itself under Heated circumstances
- ECU fault


Intake Charge temp sensor thats located in the intake was the Issue! Get this, i have a MAC cold air intake and the sensor is the *plastic* bodied screw in one.

The sensor tested fine... here's the Gotcha part:

The CAI , after the car was shut down hot, would heat soak and cause the air temp-sensor to read very very hot. The ECU would attempt to compensate for this on start and the idle would surge and stall.

Solved (temporarily) by plugging the hold in the CAI and moving the temp sensor to the fenderwell (open air). Car idles, hot or cold, like stock.


Rebuilt 302
GT40p heads
Trick flow TFS stage 1 cam
shorty bbk headers
Underdrive pullies
Trickflow streetheat intake
Mac prochamber full exhuast no-cats.

Car puts down about 250 hp to the wheel per last dyno run.

Its nice to have a daily driver that starts AND idles.

Hope this helps!:nice:
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