Hi , im pretty new to this site and just thought i would say hello and HELP!!!!!!!! ...... i have just rebuilt the top end of my mk4 xr3i 90 spec and i have fitted a mild fast road piper cam , valve springs , valve stem oil seals and followers ( tappets ) . I then took my car over to get tuned and they corrected the fueling etc. and as i was driving back home i opened her up a little and at 5000 revs it started to struggle then when i pulled up to the junction it died !!!!!!!!! after a bump start i had to keep my foot on the accelerator to keep it going and to me it sounded like my battery was dying but after i left the car for about an hour it started no problem ! any ideas what could be causing this ??? is there anyway a pressure build-up somewhere could cause the engine to struggle to turn over ??? please help i have already spent almost a grand on the engine !!!