Just a couple of other things that could cause problems like yours...

Something else to check is to make sure you have sufficient voltage in your battery and that your alternator is charging properly. I've had issues with slipping alternator belts which caused the alternator to not keep the battery sufficiently charged. As the voltage decreased, I was getting a stuttering (from ignition misfire) similar to what you describe while at cruise and under load. Fixed the slipping belt issue and the stuttering went away.

Just last night, my wife told me that the car was occasionally "hiccupping" at cruise speed. Since I hadn't changed the spark plugs lately (can't remember when they were last changed- shame on me!), I put in a fresh set of NGK's and the problem went away. The old plugs have been in there at least 5 years, and had some white fluffy deposits on them. The gap had opened up from erosion to nearly .050", gap is supposed to be set at .028"-.031".



billy242
1980 242DL with lots of GT and IPD stuff