I have a 1995 1.3 k11 micra That I have owned for 10 years. that has never given me any problems but recently has started to misfire badly when accelerating. It idles ok and the problem seems to appear after the engine is hot.

I have replaced plugs/leads/fuel filter and fitted a second hand distributor but the problem remains. Local garages seem a bit reluctant to take it on "I would just have done the same as you mate" and suggest a main dealer. Problem is the car is oldish and I need it each day for work and although I trained as a mechanic decades ago I don't understand all these modern cars (post 1950/60s). I'm inclined to suspect the fuel system including the throttle body, any thoughts? and wonder if there is anywhere where they can diagnose the problem without costing too much?

Thanks for any info