periodic high idle????????

[gsx7707]

has this ever happened?what could cause it?after full throttle pulls sometimes my car revs to about 4000.checked throttle it is closed but just as it appears it goes away and car runs fine.

 

[Boost_Addict_88]

How long does it stay at 4k after a pull?

 

[beihl304]

I have the same problem every now and then it idles at 3 grand or so but stops after idrive it on the highway for a bit.. I was thinking Bov but not sure...... Any ideas?

 

[twdorris]

It's possible that you have an intermittent idle switch signal to the ECU. If the ECU doesn't see the idle switch go active when you let off the throttle, it will not make any attempt to idle the engine. The net result is that you end up running whatever engine speed the thing wants to run at until the idle switch starts working again and the ECU suddenly switches to idle mode.

A datalog that includes idle switch and TPS should clarify when this happens. I would also include ISC position so you can see what the ECU is trying to do and whether the engine is actually responding.

Thomas Dorris

 

[beihl304]

ok thanks ill see what i can do............. also when its idleing high on my safc it says my throttle position is at 3% or sometimes 5% then

 

[twdorris]

ok thanks ill see what i can do............. also when its idleing high on my safc it says my throttle position is at 3% or sometimes 5% then

Sounds like a clue to me.

It may be that the throttle cable is too tight too.

Thomas Dorris

 

[beihl304]

i thought that but when i checked it was actually needed tightened some