I had my car tuned at the beginning of October after which it ran great. I have done well over 300 miles with no problems. After awhile the battery warning light kept coming on so I decided to change the alternator for the one from MX5 parts (UK). On Thursday I fitted it and I went for a drive and all seemed well, I was driving through Hope in Derbyshire (The drive through Hope village was at 30 mph and in 4th) and the car started missing, I stopped and checked for what had caused it, I found nothing. So I drove back home and it happened again just the once more, I again stopped for about 10 minutes then headed for home. I drove about 20 miles and the car ran great, no faults.

On Friday I check the car over from top to bottom could not find anything the obvious which may have caused the missing. I went for a test drive all seem well for about 15 mile then it started again. I have recorded a data log in Tunerstudio. I dove home again no fault showed. I have included my current tune.

The drive through Hope village was at 30 mph and in 4th.

Log titled Furness Vale: the faults are a 1779.745 sec, 1785.186 sec, 1791.337 and I think there is one more towards the end.

 

There is somthing strange going on with your VE around 3200-3300 rpm and ca 100 Kpa. The logged valus do not correspond with the table. Try reloading the tune, if this don't work reflas the firmware!