engine misfire when warm flashing engine management light
Hi i have a 52 reg 1.8 mg zs. Yesterday on my way to work after about 15 mins the engine started to misfire then the engine management light started to flash. I pulled over, called RAC and waited about half hour. When they arrived he turned engine over & could not find any problem. So he escorted me to work, about 10 mins, and it didnt happen again. On way home i went another route off motor way & went steady, It appeared fine.
Partner did a service on it last night, changed oil filter, fuel filter etc.
On way to work this morning after 15 mins exact same thing happened. So i waited a while and started up again, only got half mile before it did it again. Waited a while and only got 200 yards this time. Every time i restart the light is no longer on.
Called RAC he did diagnostics, gave error general misfire.
I'd been waiting over an hour this time so he escorted me back to garage. Yet again the problem never happened. Rac guy advised garage to check coils.
They've just told me that after 2 hrs looking at it they still have not found problem. They took it for a test drive themselves and it did the same to them.
What could it be?