i have a 98 s10..in my shop//with a 2.2.
the problem is an intermittent no start no crank...which i knw can lead you in 1000 different directions.
but heres what ive done..
i have replaced the keyswitch and lock cylinder..was worn..and the small wiring harness that goes from keyswitch to ecm.relearn process has been completed.
rewired clutch switch once..and lter disconnected.
found an after market keyless entry and alarm that had been hooked up and disconnected by previous owner..and bunched up under the parking brake..so i disconnected and bypassd all of that..cause it was grounding out behind the park brake pedal..been in to the wiring harness from pcm to make sure there no loose connections from key to pcm..nothing..
and still has the no crank issue goin on..just once in a blue moon..the guy will come out to start it up and gets nothing..
could there be an issue somewhere in the instrument cluster?
ive seen that happen on several vehicles but never on a chevy..

thanks
shawn

 

I have a 96 lumina that would crank, but not start. No codes. Turns out to be the crank position sensor. If you have an ohmeter, I'd suggest pull it, ohm it should be around 1K, AND make sure the magnet is still good. I check mine holding the end next to a small pile of screws. This not even be close to your problem, but it's one less thing to look at.

 

I should also add, when it dosen't crank/start do you have the oil, security lights ect. on?