rough idle in drive only?
the car is a 94 chevy C2500 5.7 TBI 4l80e
the problem is rough idle at running temp in drive only in park or neutral its fine.
changed IAC valve and cleaned out its bore, changed o2 sensor, changed plugs, checked TPS with multi meter seamed fine, cleaned throttle body with toothbrush and cleaner, put in new coolant temp sensor.
any idea on what could be causing this??