Guest ashnicholls Posted August 31, 2006 I have fitted an XU10 head to my 1.6 XU with twin webers With what I think is standard 1.9 gti cam. To time it up do you do it in the same fasion as with the standard head? Ie Line the crank up and the cam up with the holes put a dowel in both and fit the belt. Because I have done this, but the car was running crap. Missfiring. Backfiring and spitting out of the carbs. And it would not idle. So I advanced the cam timing using my vernier, 5 degrees (well 5 of the marks on the verneir), The car started to run alot better. Not as much miss firing and back firing. And idled better But upon driving it, it was slow to pick up, like it was missfiring. And still spitting out of the carbs. So I advanced it another 5 degrees. Which made the engine run better again sounding alot sweeter, still with spitting from the carbs but this could be due to jetting. It still isnt revving brilliantly though. Especially as it has a lightened fly. So is it a hotter cam, requiring more advance on the cam?????? Or if not what the hells going on, why is this happening????? Any help would be appreciated. I have a car sat out side with a nice engine it, that wont go, and I have been playing around with it for 3 weeks now, I have had to borrow the next door neighbours crappy old citreon diesel everytime I need something. And I am getting suicidal now. Cheers Ash Share this post Link to post Share on other sites
Guest ashnicholls Posted August 31, 2006 Would the fact I am running a 1.6 carb dizzy make any difference as well on the ignition timing. I would have thought it would only make a difference on the advance curve??????????? Share this post Link to post Share on other sites
welshpug 1,657 Posted August 31, 2006 seeing as youve been altering the cam timing have you re-set the dizzy timing to what it was before? if not you're 5 degrees (or however much you altered the cam timing by) out!! Share this post Link to post Share on other sites
Guest ashnicholls Posted August 31, 2006 Yes played around with the dizzy timing, found the ideal spot with each cam timing change. Share this post Link to post Share on other sites
pug309twin40s 1 Posted August 31, 2006 sounds like the timing is out or ht leads in the wrong order. stop fiddling with it and take it and get it setup properly. could also be the jetting is not right and if the jetting isnt correct it could make the engine run crap or not pull properly. Share this post Link to post Share on other sites
Guest ashnicholls Posted August 31, 2006 Yes i would take it to be rolling roaded tommorow if I could, but the engine still needs running in. (New rings, bearings and seals) Cheers Share this post Link to post Share on other sites
