Hi, I wonder if anyone has any ideas that might help with a problem.

Trajet 2004 2.0 litre GSI petrol - MISSFIRING AFTER WARMED UP

The car has 72k miles with full main dealer history.

Car seems fine when cold, but after approx 20-30 mins of running starts a more or less constant intermittent misfire which is worse at low revs ie 60mph on the motorway in 5th gear. Keeping engine above 3000 rpm lessens the misfire. Turning A/C on sometimes aggrevates the problem.

So, the Hyundai main dealer have spent a lot of time on it.

Diagnosis No.1 - dodgy spark plug.
Diagnosis No.2 - regulator pipe split.
Diagnosis No.3 - new coil packs and plug leads required.

new coil packs and plug leads fitted but made no difference to fault. old coil packs and plug leads are being refitted to car so I can get my £ 300.00 back.

I noticed that the camshaft position sensor support condensor (that is fitted to the outside of the small casing) had come adrift and was shot so I fitted a new one but this made no difference to the fault. it is possible this condensor has been out of circuit for months. shame the Hyundai main dealer did not notice this and suggested it was just an earth when I pointed out the problem !

the Hyundai main dealer now says it is either a valve or injector problem but diagnosis alone would cost more than the value of the car.

does anyone have any ideas that might save my Trajet from the scrap yard, thanks to all for reading and any help.