cutting out when warm

had this problem a little bit in the past where the engine cuts out for a split second then comes back on again and backfired at same time. last few days has done it more often and yesterday totally died on motorway. I waited hour for recovery and kept trying every 10 minutes but kept just turning over. after a while it started and ticked over fine but when I flipped the throttle it died and wouldn't start even after 30 minutes. it's now in the garage and it started first thing this morning mechanic checked fuel mix etc etc and everthing fine. as soon as reved it cut out and there was no spark from leads until went cold. he has now changed the ignition module but hasn't made any difference. if you leave car till cold starts up again and cuts out when revs. it's a 1.8 gti and in last 3 months has had new leads, plugs, cap, arm, coil and warm up regulator! any ideas anyone please??

hall sender and wiring would be on my list, also check ignition switch. you should get 12v to black wires on coil with ignition and cranking. if low voltage or power loss when cranking get a new switch. to test run wire from battery direct to coil + side, if car runs then you know you are loosing power to coil

cheers jonny. ended up replacing whole distributor and is fine now. just to comment thow for people looking in future. when i got bosch part number off dizzy my local autofactors said obsolete and a company off ebay said £305 from germany. i googled bosch number with no joy but then googled the vw part number off dizzy and it took me to a mk2 forum where it had a list of 15 bosch  part numbers that were the same dizzy. i then rang autofactors back up and went through numbers and the 3rd one came up for £130. not sure if id gone through whole list would of got cheaper or same. just to let people now in the future!!!