Hi,
Recently had a new coil pack and sparks fitted to car, ran great bringing home from Glasgow AVA, they left the oil cap loose which meant oil went over engine all on spark plugs. I cleaned this out and replaced the cam cover gasket and half moons which appeared to solve the problem and no more oil was visible.

Took car out again to AVA to get the once over to make sure running fine, ran great all the way there and on rollers, and home again, however took car out next evening and it cut out on me, took a while to get started, sometimes starts on what seems like 2 cyclinders, heavy backfiring, strong smell of fuel, if I leave it for 15mins, it will drive great for a few mins then same happens again, cuts out.

AVA advised to check multiplugs at passenger side wing, done this and all fine, no corrusion.

Any suggestions what I should do?

Much appreciated.