Scirocco Register

Getting desperate on this.

My commute is now further & uses the very busy A37. Ever since this I have had issues with the revs dropping off, the car stuttering & eventually stalling at lights or junctions. It generally starts to happen about 7 miles into the journey & is usually apparent after I've been travelling uphill behind slow moving traffic. The car starts first time afterwards, although I made the mistake of giving it some choke a few times which just flooded it & made things worse.
It's a GT2 with Weber carb. So far my mechanic has cleaned out, reset & retuned the carb (twice), replaced rotor arm, fitted new fuel pump. I replaced the filler neck, tank & fuel lines about 7 years ago.
Any advice or help please

You could try a restrict the fuel return pipe to see if that helps or short term test, remove the fuel return pipe and block it off.

Have a google on the web as it seems to be a common problem with a Webber fitted and same for Mk1 golfs..

Thanks Mark,

Update - secured a cable tie around the fuel return line. This helped with stopping her from stalling at lights/junctions. Still jumping/missing whilst driving though. Driving uphill has improved.

Any more ideas?

Check your HT Leads for arcing at night, check the gasket behind the fuel pump as well. These can deteriorate and cause small leaks resulting in lack of fuel or air leaks, not enough fuel due to small fuel leak. Feel your pain, Webbers are fun, you always get home but the start stop , restart is a pain in the !!!! if your car is having issues. Been there and got the t-shirt. As you have replaced the dreaded filler neck, fuel lines, check the sender in the tank. Is the gauged bit in the sender in the tank still working or does it need cut out a bit to allow more fuel to come through. Good luck. All my cars are now injection, but I always thought that the acceleration from 0-60 with a Webber Carb on a Scirocco when set up correctly was awesome!!

I understood you changed your fuel tank and lines several years ago.

What does your engine bay fuel filter tell you? Any particles on inspection?

Check the vacuum suction at the carb. Might be worth getting a Vacuum & Fuel Pump Pressure Test Gauge Set.
I had a fuel starvation problem which turned out to be the inlet manifold gasket. In my posts... I like you nearly went over the edge.

I had a very similar experience with the Weber carburettor fitted by a previous owner to my 1.8 Auto GT2. This included restricting the fuel return and finding that whilst stalling was improved the car still bogged down a bit while driving. As it was my aim to restore the car to stock I replaced the Weber with a refurbished Pierburg. However, when I did the work I discovered a small and hard to see crack in the hard rubber mounting flange which I suspect was ultimately the cause of remaining problems with the Weber. I’d always planned to replace this anyway when fitting the Pierburg. They crack along the corners of the moulding and it’s very hard to tell. If yours isn’t new during your ownership I’d feel inclined to replace it as it’s relatively easy and the part is not very expensive. VW part number 026129761E.

I also routed my incoming fuel line by lengthening it towards the rear of the headlight pulling it away from the cam belt cover in order to keep it cooler. Make sure its well secured and won't flap about near the alternator belt. On the Weber make sure the aluminium flange at the bottom is not warped.