Need some advice on a Mk2 GTI 8V with Weber 32/36 modification

**rutti** · 19-07-2011, 08:39 PM

Hi All,

A recent purchase. Real fun to drive if it doesn't stall or if it idles properly

Basically, I had re-adjusted the idle mixture and speed screw last weekend, set rev to 1000rpm, was sweet. But tried starting a few days later when cold, it only managed to start after a few tries (with full throttle). Then I had to step on pedal to maintain idle speed for it to warm up (if not it just stalls on its own). When it warms up its fine, it will go ok when driving but sometimes, it will stall (can see the rev dropping slowly) at the lights (have to practice heel-toeing... to keep the engine alive... heeeheee). I have checked static timing, ignition timing (with timing light) all good according to Haynes manual.

Its a new electric choke DFEV 32/36 Weber that was installed recently (1 week before it got sold.. self installed). Its got a street cam and 4-1 headers... not sure if this info is of any use in my quest to get this car tuned properly.

I would like to hear some advices from your experience with putting a weber 32/36 on a digifant 8V (RV) engine.

Below are some questions i came up with after reading thru various weber 32/36 installation on this forum and elsewhere:-

1) Currently the fuel tank pump is used to supply the fuel into the carb with a Tee fitting (return to tank), before i go out and buy a fuel pressure gauge, does anyone know the pressure rating of this pump? I know a Carter 4070 have been recommended but not sure if its too big for a 32/36.

2) Since Weber carbs requires larger volumes of fuel.. what is the recommended fuel supply size?

3) Ignition Timing.. since the advance timing is controlled by ECU thru the hall effect and I am using Carb instead of digifant, should the ignition timing be similar? (6Btdc?) I checked the timing last week with timing light (CTS removed, at 2300rpm, I could see the advanced marking on the flywheel)

4) The only air line fitted to the carb is the emission breather output hose into the carb. Is there a need to fit a vaccum line into the body of the carb (previous owner had plugged what appears to be a vacuum port just above idle mixture screw)

Thanks for reading and hope i can learn something from fellow dubbers.

**h100vw** · 19-07-2011, 08:46 PM

I don't think you will find anyone that has done a carb conversion to a GTI??

I bet the fuel pressure is way too high for the carb even with the T piece return installed. The digifant pump would be 40 or 50 PSI from memory and the carb would want 10% of that or so...

I'd be looking to re-inject it unless you have a very good reason not to.

Gavin

**rutti** · 19-07-2011, 08:54 PM

Originally Posted by h100vw

I don't think you will find anyone that has done a carb conversion to a GTI??

I bet the fuel pressure is way too high for the carb even with the T piece return installed. The digifant pump would be 40 or 50 PSI from memory and the carb would want 10% of that or so...

I'd be looking to re-inject it unless you have a very good reason not to.

Gavin

Woah... so an Aussie first?! heee

Anyway, the main pump (higher pressure) have been removed, its the low pressure transfer pump (pump fuel from tank) i was referring to.

Well, I will see how this conversion plays out.