Markmartin01
Newbie
91 RCSB Z71, stock under the hood other than a small Elgin RV cam. Has always ran fine, started it the other day and it has an occasional rough idle and what sounds like a lean condition under low RPM load, haven't tried WOT as that just sounds like a bad idea. Cap, rotor, wires are clean and fine, new ICM, coil is fine, fuel pressure stays at 12psi, no vacuum leaks, distributor has no end play, injector pulse isn't a perfect fog but it never has been. It does idle hunt occasionally now which it's never done. Seems mostly normal dead cold but 2 minute of run time and it's unhappy. Did replace 02 just in case but it didn't help. Any idea of what to check next, i'm running out of ideas. Only code is 43 and it's had that forever off and on so unlikely to be related. Open to any troubleshooting steps i've missed, i'm out of ideas. Really thought it was going to be low fuel pressure but gauge proved that wrong.