either bad gasket under throttle body or bad iac valve
Could be a very dirty fuel filter.
1990 gmc p/u 5.7 wont idle showing code 12
possibly a vacuum leak, low fuel pressure, or the idle air control has failed,
Check the fuse
Check the throttle position sensor or the idle control motor
I would replace the ignition module in the distributor. Also need to make sure the coil and wire is good too.
stopped up fuel filter or poor fuel delivery
Could be you need a new fuel idle motor. Or you need new spark plugs
Carb needs curb idle adjusted or rebuild.
my 1989 Chevy 4x4 front differential wont engage any idea on how to trouble shoot the solenoid on the front pumpkin would be great
have you checked the fuel gauge itself to make sure it is working
The vehicle speed sensor in the transmission may be bad.