Hi all, Just had the driver set up on the rolling road after the rebuild etc... and the guy that did it (Airey Tuning) set back the dizzy timing to 15 degree's (I think) and took off the vac advance pipe telling me to never ever ever put it back on no matter what anyone said... After talking to a mate about this he seems to think this could be a balls up and that the vac pipe is essential to the spark timing working correctly as the revs go up... It is running fairly well apart from cutting out at lights etc... but that is possibly to do with a temporary crappy throttle arm set up... So... Whats the dealeo? Is the pipe necesary or is Mr Airey right in taking it off and retarding the timing? Cheers, Jay
Is the car modified in any way? There is a school of though that says not to run the vacuum advance on a 2L conversion as they generate more vacuum earlier in the revs and so the advance will cut in too early. I've got a GTi cam and Weber on my 1.8 and the vacuum is hooked up and it runs just fine. VW wouldn't have fitted one if it didn't need it, its not like they don't know what they're doing. That said if yours runs sweet I'd leave it as is. Did he say why he'd taken it off or just give you a bit of mechanic's voodoo? Barkstar
It was summat to do with low rev speed... I don't think it made any difference at all tbh apart from beign more stable at idle... It's idle is way too low now though and cuts out again... The engine has had a fair few mods (although it was disappointing on the rollers!)
What power are you getting? What mods and 1.6 or 1.8? If thats the best explanation then I'm hearing Voodoo - don't twiddle with it yourself take it back and get the tickover sorted. Barkstar
It's a 1.6 and got a gti cam, full stainless system, weber 38dgms, ported and polished head + both manifolds and gti downpipe... Its putting out 86whp... I've noticed weird flatspots at the start of every gear change too and it coughs when you boot it from low revs (ie - foot down - *COUGH* goes nowhere - thennn goes... ) Goes well in mid rev range tho... takes off about 3500 > Jay
That's the carb. The 38 DGMS is usually fitted to a Ford 3L V6, and has a pretty big choke for a small engine, so the symptoms are to be expected. Longer term you may be better getting a 32/34 DMTL - the usual choice to replace the Pierburg. Is the 86bhp at the wheels or flywheel? Barkstar
Don't think it will particularly be the choke problem but progression drillings in the body of the carb are unlikely to be ideal for a 1600VW and it will take A LOT of setting up and expertise with emulsion tubes and jetting to make it run half well. Having said that a DGAS did work very well indeed on a 1600 Ford Crossflow of mine many years ago
Hmm, it may be that the vac advance for the carb dizzy is all wrong, I'd think about fitting a GTI k-jet dizzy. Oh and the dizzy timing should be set to 6 degrees BTDC cos you now have a GTI cam, thats probably why you have a flat spot! If you check the haynes it tells you how to mark the flywheel
Sounds a bit odd...did he actually block up the hole in the carb/inlet where the pipe goes to...otherwise your rough running is because you've got an air leak. The whole thing sounds pretty iffy to me.
Whats wrong with that? You said you where disapointed? Theyre 75bhp at the flywheel standard. You've gained 37hp and you've made gti power!
