« on: August 28, 2012, 07:48:08 PM »
If it wasn't backfiring before the tune-up, something must be wrong with the firing order, the dist. caps misaligned, incorrect plugs or gap, something had to change right? I think #1 on that one is on the left front of the cap(from the drivers seat) then the rotation is CW - 18436572.....rt bank 2468, left bank 1357....The other problem of cutting off at low rpm's could be many things(like Discrete said) but a fairly common and often overlooked item is the pick-up coil in the dist. When they get old and corroded they will often have a weak signal at low rpm's, but since its so close physically to the ig mod where the signal is going, it'll hang in there showing only intermittent problems, longer than it should, lol! Stalling at low rpm's is one symptom, erratic spark, weak spark, my truck(93 chevy tbi) would actually start up and run by shooting a little starting fluid in the snorkle, when it wouldn't start normally...once I got it started, it was OK, till I let the rpm's drop, then it would cut off again = more starting fluid.....almost acted like a fuel problem, but I'd take the top off the air cleaner and watch the injectors spraying a good cone of fuel, and had a spark, it was just orange looking, rather than a bluish spark....the pick-up coil fixed mine.