Thanks guys, here we go......... 1980 El Camino, 4.4 ltr...267 V-8..... 190,000 miles....... always runs great...new timing gears and chain 10,000 miles ago...... regular maintenence..... daily driver...... vehicle developed a "falter" a few weeks ago...... found bad gas in the tank, emptied as far as possible with a siphon attached to the supply pipe at the engine compartment, removed the carb and dumped out and cleaned....then rebuilt carb, very little carb wear, evidence of it being a replacement carb prior to my owenrship, (Rochester Dual-Jet)... no change....... new plugs, plug wires, rotor, cap, condensor harness, new fuel pump, new battery, new fuel filter, new choke pull off/ found old one leaking-replaced..... switched the ICM with an old one to see if there would be a change -negative........ lot's of time spent going over all of the vacuum lines, this "falter " doesn't occur till the engine warms up, then it's not a "full" falter.......rather like two or three plugs are switched off and turned back on again....... same on flats and hills.... we have hills around here at Hood Canal, Wash. state.............. distributor flyweight springs intact, vacuum advance diaphram works, could this be intermittent? This "falter" came on very slightly over 20 miles and stays at the current level now during testing and observation...... almost reminds me of a ignition switch going bad the way the car feels when running,,,,, "falter" occurs when warm just above idling when changing rpms and listening to engine with hood up....... thought cleaning the carb would clear out any passageway issues that affect the idle mixtures....... timing set at spec, idle air mixture jet seeming set properly........ got me and a paid mechanic scratching our heads....... next ideas....... fuel treatment if there's just a bit of crud left in the tank, ignition control module...... I always thought the gms usually just die completely unlike some others that act up before becoming unoperable....... hummmm???? thanks--- akbolt
