Engine stubbles at idle speed

wildmanbaker wrote:
You should not see more than 300 ohms on any wires. Lightly pull and twist the wires as testing them, as their may be bad areas on the inside. Bad wires usually do not show up at idle, as it only takes about 5,000 volts to fire the plugs. As loads increase, it will take more voltage to jump the gap, and that is when bad wires show up. Has anyone put a timing light on it? IS the timing jumping back and forth more than 5 degrees? Check slop in the timing chain by turning the engine forward until you see the rotor start to move, then turn the engine backwards until you see the rotor move the other direction. If it takes more than 10 Degrees of movement at the crank pulley, it may be the timing chain has jumped a tooth. Keep plugging, and let us know what turns up.

. Talked to the mechanic at the shop he checked all the sensors and found no problems. He was thinking that it was a timing issue also. He was going to do a compression test tomorrow morning to see. He said that vintage had nylon gears and the gear could have worn gradually. He said that they usually go bad at 80k miles or so I have 113k now. If it jumped a tooth it would have happen all of a sudden. Sounds logical to me but so did all of the other suggestions. I was surprised to learn Chevy used nylon gears I thought they were steel. I gave him your idea also to check for the 10 degree movement.