i have a 88 iroc 305 5 speed, replaced distributor, coil, plug wires, plugs,
egr valve,mass air flow sensor, cleaned the iac valve. set timing to o deg
before pluging in gray wire on firewall. ohmed fuel injectors all are 16 ohms, fuel pressure is 40 psi. the motor runs great from 1500 rpm to red line but acts like
its running on 6 or 7 cylinders at idle engine speeds.
also no diagnostic codes.
any and all ideas would be gratefully appreciated......

thanks for replys.

 

Sounds like you covered everything . That leads me to ask if you checked compression ratio? Compression, fuel & fire ... With that stated have you doubled checked all of your vacuum lines under the hood & dash for a leak? have you cleaned the injectors as well?

 

vacuum leak ?
i have checked under the hood for a un plugged vacuum line, but
diddnt think about under the dash. thanks for a new direction troubleshooting this problem.
also question on the injectors, they all are the same resistance and dont leak down with the ignition off. i thought if they were messed up they would be more of a problem at
midrange and higher rpms. my car only misses at idle and right above idle.
thanks for the help

 

There are people in here more experienced with injectors than I . but my thinking is if one is spraying ugly it cause a miss fire at low rpms. Too Much fuel or too little?

 

you were exactly right, i replaced the injectors and it runs like new again....
the oem injectors were filthy
90k on car but it has sat stored for much of its life.
another thing these cars were not designed with maintenance in mind
the tpi system and fuel injector system is a PIA to work on.
thanks again

 

I am glad you got it fixed.