My 98 is automatic and after a few problems my truck wouldn't run ight. went through a lot of spark plugs. Now that that problem is resolved for now when I start up my truck from just being running the revs don't stay up. They dramatically drop to about 500 rpm but hen go back up. I am very worried about this problem. Now the truck completely stalls out and turns off, need to pump gas for it to go back up. But after that truck runs fine. Anyone know what the problem is?

 

sound like its the IAC valve or MAS, possibly even the TPS, try scanning it, and cleaning out the IAC valve and the MAS.

 

It was the IAC thanks a lot

 

hey your welcome, glad you got it straightened out