I have an 89 Chevy K2500 4x4 350 auto with 135k miles. I have experienced occasional high idel problems but recently has escelated to engine sugres and most recent stalling and/or not starting. If I get it started and get it into gear and excellarate hard it will go but as soon as I let of the peddel it dies. I've had it checked by (2) different "Dealers" and they couldn't find anything via. dignostics. Help!!!

 

Fuel pump, fuel filter...?

 

throttle postion sensor?