Toyota Carina E 1.8GS Petrol 1997 Manual - Intermittent Misfire - V4 Heaven

Hi all, My previously 100% reliable car has developed a misfire. It is very intermittent, ie one minute the car's running as sweet as a nut, then it misfires for anything from 5 secs to 20 secs, then it runs fine again. It doesn't seem to happen when the engine is cold, only when it's thoroughly warm. It has just had new plugs and HT leads but this hasn't made any difference. The distributor cap was dusty but this has been cleaned out and it has no signs of cracking. The pins in the distributor cap do show signs of wear but they are all intact. The rotor arm is a little rough but intact. The car is regularly serviced and has a FSH. Fuel filter (I think) is about 10,000 miles old. I have tried a new tank of petrol from a reliable source and even some STP petrol injector cleaner but the problem persists. I would be grateful if anyone has any advice! Thanks.

Edited by V4 Heaven on 26/09/2013 at 11:36

Toyota Carina E 1.8GS Petrol 1997 Manual - Intermittent Misfire - V4 Heaven

UPDATE: I googled similar problems and these pointed to a dodgy fuel injector. The next time the car was misfiring, I put a long screwdriver to my ear (the blunt end!) and put the pointy end on the top of each fuel injector in turn. This acted like a stethoscope and I heard 3 of them ticking away nicely and one wasn't.

I bought a second hand part from a spare parts dealer and this was relatively straightforward to fit. Have done 100 miles since and there has been no re-occurrence, so it looks like it's cured now. Thankfully a cheap fix and a return to a trouble free commute.