I just purchased a 1993 xjs conv. with a 6 cyl. engine. When starting cold (winter cold) the engine searches to find the correct idle. It goes from 1400-1600 down to 700-900 rpms. I have to keep me foot on the gas to keep it from dieing until it warms up, then it appears to smooth out and idle at about 900 rpm. If there is a cold start module, wear is it located in the engine bay or is there something else I should be looking at.
I was hoping that giving the car a minor tuneup might make a difference, so I installed new plugs, and cleaned the throttle body by spraying injector spray in it and it didn't seem to make a difference.
Any suggestions would be greatly appreciated.

 

i read about a guy who had a 4.0 with similar problems his problem was a split vacumn line.Have you checked all the vacuum pipes, including the ones which go out of sight eg to the resovac unit? Also there's another vacuum reservoir unit, hidden under one of the front splashguards
when its cold the line with a crack would be leaking more than usual when its decently warm and expanded.

also i don't know about newer ones or i6s but the 5.3 has a cold start and its basically in a valley. I don't know anything at all about them. but from looking at a picture the plug on it is the same as a injector so I guess it works off a sensor and at certain temps it injects extra fuel to the system.
Could be totally wrong on how it works but if its dealing with cold weather that could easily be your problem....lets wait and see if there is anyone else round here with more knowledge on it.