Hot surging idle

DemonGT

Founding Member
May 24, 2002
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Sparta,WI
When i cold start and engine is going though its warm up idles is fine. Once i have drove car some and it nice and warmed up it has a surge when stopped idling at
a stop sign. What are common causes of a warm idle surge.

Current tune attached. I did do a log but its to large to attach.
 

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Warm idle surge can be caused by unstable ign timing or a lean condition/ rolling AFR.
I only altered the IGN advance curve during idle, you can think of this as a idle stabilization curve
 

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When i cold start and engine is going though its warm up idles is fine. Once i have drove car some and it nice and warmed up it has a surge when stopped idling at
a stop sign. What are common causes of a warm idle surge.

Current tune attached. I did do a log but its to large to attach.


Has your car always been a 5 speed and do you have the clutch switch bypassed?


Do you have a wideband controller hooked up? Widebands work faster than narrowband to keep the engine in tune better when hot.


Whats your fuel pressure when this happens? What fuel pump are you running.?

How are you performing your base idle resets? The base idle setting can affect the engine when its hot if the IAC has to work harder and do it constantly..

Do you have the black CCD or the gray TFI module installed?

When was the last time you changed the 22k ohm resistor near the EEC plug?...When they fail they stick open and allow full voltage into the circuit and things get a lil crazy inside the ECU..
 
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