GTA88

I developed a miss in my beast yesterday. It was running fine all day until I started it up at the shopping center, and pulled out. Then dut, dut, dut, dut... that awful sound, and feel. It sounds like a 1 cylinder miss. You can hear it and feel it at idle with the car in gear. In neutral it's not as bad. It's most noticeable on acceleration. Runs rough. Decelerating you can't even notice it. In neutral, it will rev to 1500 OK, then get rough between 1500 and 2000, then clear up a bit over 2000. Fouled plug, maybe? Will a bottle of some cleaner possibly clear up the plug ? btw the plugs are new, only have about 1,000 miles on them.

Thanks

wm_sorg

Start with the wires. Pull the plus and check it for fouling. Look under the dist cap for corrosion. I would also check the injectors. They could be clogged.

Vader

GTA,

Wm has good advice. Pull the plugs and inspect them, even though they are "new". I've seen "new" plugs that were fouled in 20 minutes.

A complete ignition tune would be a good start if you haven't done so in the last 20,000 miles. Inspect the cap, rotor, coil, high voltage wiring, pickup coil and reluctor, HEI module connections, coil connections, etc.

Removing the plugs should give you a very good indication of which cylinder(s) to concentrate on. Plug condition is probably the best barometer of overall engine condition, short of pulling the heads.