2001 Jimmy Stalls

[PhilB]

My 2001 4X4 Jimmy stalls usually first start of the day. I know it's not looking good when the RPM starts fluctuating from about 900 to 400 at idle. Eventually it drops down to nothing and then stalls. If I keep my foot on the gas the RPMs stay up and it won't stall. Once it's warm it seems okay. Evry time I take it to the dealor, by the time I get there it works fine and they can find no codes. Any Ideas?

[Teaman3]

Check vacuum lines for leaks, and any mixture control solenoids or idle air control motors for looseness ie they've partially unscrewed, creating a varying air gap.