2003 GMC Sonoma, 4.3L v6 vin X, 2wd, auto. 100,400mi.
Truck idles at 600rpm. Idles at 1000 until the temp gauge starts to move, then drops to 600. Idle jumps for a sec with A/C switch, but goes right back to 600. Power steering doesn't seem to affect it either. Truck drives at 1600rpm and feels like its in 3rd and OD is off. No Check engine light, no codes.
Not getting much help at S10forum, so figured I'd ask here too.
While doing another unrelated repair, broke GM's cheap plastic distributor housing and had to order a new one. While I was in there, finished rest of tune up stuff. Truck just got new distributor, cap, rotor, plugs, wires, pcv valve, fuel filter. Replaced several dry rotted vacuum lines, clean air filter. Somewhere in all of this, the problem occurred.
Distributor hold down is not adjustable on these. When I installed it, it was close, but not on the line I'd made with the old rotor. I moved it forward one tooth, way off. Back one tooth, close again, back one more tooth, way off. So, I'm pretty sure its installed correctly, though can't exact match previous marks. Was told it may need cam/crank relearn after distributor changes.
I cleaned IAC and throttle, no change. Spray checked all vacuum lines for leaks, no more leaks found.
Took it to mechanic today, "Timing was off 3 degrees, scan tool relearn set back to zero"
Runs slightly better, around 1300rpm at constant speed, but still idles at 600, and still feels like O/D is off.
Mechanic said, I might want to bore out the hold down clamp so I can adjust distributor. I'd rather find a less ghetto solution first if there is one than me custom fabbing parts.
Any suggestions welcome. Thanks!