I recently developed a slight miss fire on my L6 managed FRST. I have checked all ignition parts including spark plug gaps and both crank and cam sensors but its still happening.

I dont use the car very often in fact over the last year its done about 2,000 miles so on this occasion its probably been about 4 months since I put a tank of Shell V power in.

Could this be causing the problem? Its just on the red part of the fuel gauge and I'll be putting a fresh tank of fuel in at the weekend.

 

More likely to be picked up crap and blocked the filter with running low, 4 month old fuel will NOT cause a problem.
tabetha