i have recently come into possion of an 89 cheyenne 1500. it had been running strong since it was purchased by my grandfather when it was a few years old, but in the last few years there were some problems with it. he replaced the alternator, distributor, timing advance and recently a new computer. i also needed a new battery for it because the truck would some how drain the battery over the course of a night while sitting in the garage. we have been able to get it running strong and had it driving after it had been sitting for a few months but before that and since then it has had trouble idling. it will start and either rev right down and die or if it stays running it will rev up high, then slow right down to just about quiting then rev its self up high again and continue this pattern. any ideas as of what could cause this? and what to do to fix it? i have heard that it could be a fuel supply problem and might need a new fuel pump, but i would really like somemore input. thanks

 

not to sure its the pump because the pump only pumps the fuel , the throttel body distributes it , mabie you have a clogged venturie ...good luck

 

check out the throttle body on it. then look into your grounds. you say it kept loosing power. if you never fixed the ground problem then its probably missing every now and then and causing everything to temporarily shut down and start back up again.

 

i dont know much , and i am just a student but i have a truck identical ... i swaped a 355 small block chevy into it ..i unhook all the pc , but befor i did i had that same probleum .. i thought it was the computer constantly setting the advance ...