I've had this problem for several weeks. I've tried a few things that posters have suggested the last time I posted, and have had the van to two mechanics with no luck. Any suggestions are appreciated.
 
It's a 2.1 with about 140K miles. Within the last few years I've had the head gaskets, clutch, front and rear main seals, and rings done. Water pump went, it sat for a while, and just recently had the water pump replaced.
 
When it came back from the water pump replacement, the mechanic said he had problems with the idle. He replacemed the temp II sensor (coolant), tried a different idle control module, and a different AFM. Neither really made a difference. He adjusted the timing, and then change the throttle body. Another mechanic re-adjusted the timing, saying that it was too far advanced, and adjusted the throttle switch on the throttle body.
 
So here's what it's doing:
 
Starts up, idles at around 1500 RPM. After about 15 seconds, idle jumps to 2000 to 2600 RPM. When I start off after about 15 seconds, it stumbles for about 10 seconds as if it has fuel problems, then runs fine but still idles high until it is completely warmed up. The warmer the engine gets, the lower the idle gets, until it gets to around 1000 RPMs. Also when it starts up, the engine rocks a little, and doesn't start as easily as it used to. 
 
Any ideas? 
 
Thanks, 
Ed in CT
_________________________________________________________________
The best games are on Xbox 360.  Click here for a special offer on an Xbox 360 Console.
http://www.xbox.com/en-US/hardware/wheretobuy/