can anbody help me. i have an 87 s15 jimmy 2.8l with throttle body, the engine starts but quickly dies unless i pump the gas pedal. If i hold the gas pedal then it it just drops rpm's and dies. I change the injectors, fuel filter and rubbed away some corosion off the distributor cap, checked the spark plugs and wires but i still cannot find the problem. Also i put a 5.7L injector into it and it ran it just burn't extremely rich. I have a timing light but i dont know if there is a wire i have to unplug before i check the timing and i dont know what degree i should time it to. So please if you have any idea what is wrong or anything about the timing please help

 

Hmm.. check for any vacume leaks or a hole in that black plastic "ball" on the fender? there should be a brown wire on the passenger side under the carpet that needs to be disconected before setting the timing. That would bypass having to use a jumper in the diagnostic port. Are you getting any codes?

 

TPS sensor may be acting up possible. Or maybe even the IAC.

 

Okay thanks, but what is an IAC and how would i know that that is the problem?

 

IAC = Idle Air Control. It should be on your throttle body. Usually you can just clean them and they are good to go, you should try that first before you go out and buy one.