Would appreciate your advice! I have a '92 with 33K miles on it. Very clean -- always garaged and driven only on nice days (convertible).

It has an intermittent miss at idle. Just a nuisance but would like to fix it. I took it in for the 30K mile service (never performed before) and changed the plugs, wires, cap and rotor, hoping that would clear it up. It is still there. Basically every 5 to 10 seconds or so it will get a miss (i.e. not continuous). My friend says to try injector cleaner next. Will do that this week. What is the list of likely culprits? Should I just do some basic things myself then take it back to the shop if that doesn't fix it? I had intermittent miss trouble with another car and the mechanics could never clear it up, so I'm pessimistic about the shop being able to track it down if it isn't something simple.

 

Had similar troubles with an old 305 once, it was a bad coil.

 

I had the exact same problem. It was hard to diagnose because it wasnt a dead miss, and all cylinders miss now and then at idle. It seemed like one was missing more than the others and causing irregular exhaust movement. I replaced the injectors with some mustang 19 lb/hr and it cleared everything up.