[rayhines]

I got a AU I 1999 Forte Wagon, converted to gas.
It was running rough and missing, so my gas guy diagnosed new plugs and leads and tweaked the computer settings. Seemed ok but on way home it backfired once. Then for next few weeks it would backfire at least once a day. Eventually it got a bit worse, missing, even on the highway, and to the point it almost stalled. I switched to running on petrol only, which was better, no backfire but after a while it also missed and ran rough occaisionally. I was thinking it may be electrical - like the coil pack arcing?

Went on holiday for a month and came back - the battery was flat. I charged it and started it on gas - it drove like a dream, no backfire or missing, smooth idle even with AC on. Conclusion - resetting the computer due a flat battery fixed all the problems! My mechanic had no idea about this, wish someone had suggested it months earlier, saved me running on petrol for a few months at more cost!