i have a 91 z28 with a 350. i just did a tune-up cap and rotor and flamethrower ignition module. and i hook it a up the distrubuter was loosend and was adjusting something. if turn to far one way would die. i tried to get it a smooth as possible but after warmup the idle drops to 500 and will occasionly drop to 400 and seem like it almost wants to die. i tried crankin up the screw on the throttle body but didn't seem to help. i thought the timing was electronicly controolled or does the distrubter adjustment have to do with this. any help would be appericated.

 

problem fixed . had a 7ft vacuum hose the was rotted and now runs like a champ . idles and stays a 500.

 

The advance is controlled by the computer, but the base timing is determined by the distributor position. You might want to check it now.

 

took it to the dealer and timing set to 6 deg. had nothing to do with the problem