i have an 85 gsl se and when i start it cold the idle well quikly shoot up to about 2000rpm then fall back down to about 100 and then go up and down between 100 and about 300, if i give it gas the idle goes back up to 2000 and stays that way for about 10 min of driving, then it goes back to normal, anyone have any idea of the problem?

 

Sorry man, I'm no expert on these cars but I had an old Maxima that did the exact same thing when the Throttle Position Sensor got some water in the plug and caused a short. Might want to check out the TPS, I think that the adjustment of it can do that to maybe. Good luck!

 

Do a search...this has popped up a few times recently!
I think you might use "automatic choke" or "throttle position sensor" for the search.
(Sorry I can't help...I'm a carb guy.)

 

according to longduck...proper proceedure to turn on your gsl-se is by pressing the gas to the floor once then turn the key...

what you are experiencing is normal...