2004 LS V6 Idle issue

[riclee]

I have been reading through the forums for an answer to a idle problem which happens when my LS is cold. In the mornings when the car is cold, the RPM will not go above 1000 in either park, neutral or drive, and has a rough idle. Once it is warmed up, it runs and idles smooth as silk, and has plenty of power. The following have been replaced just before I got the car from my brother. Converters, coil packs, plugs, wires. I have seen someone state that the LS has a cold start rev limiter, but this does not seem to be the problem as it will not rev above 1000 RPM in drive. I also read that the temperature sending unit may be giving a false reading, and saying the car is warmed up when it is in fact cold. The check engine light has never come on. Anyone else had a similar problem as this. This one surely has me puzzled. Thank you all for any help offered.

 

[SteveSC]

How did you manage to change the wires?

 

[msgtusmc]

My wife's LS revs to 1000 rpms everytime it is started. It will rev higher if gas is applied.
Did you check the coolant temp switch? Located near plug #5 on V6 engines, flimsy plastic connector. Mine went bad @ 80k miles. MAF clean? All hoses/connectors to MAF intake tight? PCV valve located under intake manifold been changed?Do you have correct fuel pressure @ the rails? All injector electrical connections good? Any codes?
CEL?