On a GEG holiday three weeks ago whilst leading our group a strange misfire occurred. The engine idled and accelerated normally but dribbling along or blipping the engine in neutral with very light (FBW) throttle openings a severe misfire resulted actually sounding like a V twin at some points and making progress through villages a misery with violent snatching on transmission. As a consequence we reached our destination some 15 miles away quickly
. After letting car cool down we checked all visible connectors and then wiggled (technical term) all fuses and relays in electrics box.
Engine started and then ran fine for rest of holiday but fault occured again last week some 1000 miles later during very light throttle openings in a village. Again no management lights showing. This time I was able to pull over immediately and went through the same routine although with a hot engine. Given I was on another holiday and 200 miles from home I didn't want to investigate further once I found the wiggling of components and restart again cured the issue, with no further problems on return home yesterday.
I'm now going to be looking deeper though, as a start replacing the ECU/PCM relay, re-seating all fuses etc. Will also check FBW throttle connector if I can access. I'm almost certain this is an electrical/electronic issue although not involving fuel system or its relay since anything above light throttle has the engine pulling smoothly including full throttle. It may be the temporary cure is simply the restart (PCM reboot) itself but clearly something is triggering this very intermittent behaviour.
I would appreciate comments from any other 3.7 Roadster owner especially if they have had similar.
