Check ignition timing by pointing your strobe at the 'V' on the flywheel through the hole with the plastic bung in it (with advance on the strobe set to 0, triggering off No.1 HT lead). Engine should be at full operating temperature when checking/adjusting. I'll find a pic in a minute... The bit with the red 'circle' round it in this pic should be smack in the middle of the hole as viewed from passenger wing. Ignore the green ringed bit. Edit: Did you check the vacuum hose to the distributor vac advance (pull it off the dizzy when engine is idling, should make it run horribly)? And the one from the carb to airbox?
Hi chap thanks for the info :-) Fortunatly i cracked on yesterday after posting on hear and just before the sun went down i managed to fix her!!!!! Basically the diaphram in the vacuum advance had failed. She is now back to the way she was and drives amazingly. Below is a link to pics of it in the members ride section. http://www.clubgti.com/forum/showthread.php?p=1992063#post1992063
