See the black/brown wire from the Pierburg that has been cut and crudely twisted to a black wire and earthed at the Green ball.. What is this wire for? or is it simply an earth anyway? The car is a 1.8 Scirocco GT2 and has intermittent idle issues that could be the fuel system. Doesn't idle well from cold and seems to bog down/lack punch? TBH I know all about the Pierburg guide etc but have a Weber DMTL that I could bolt on and guarantee fault free driving. Or at least eliminate potential problems.
Some 2e2-equipped cars have a control unit in/on the fusebox which can, via that solenoid valve, cause the throttle to fully close on the over-run (for fuel saving). This is done by unpowering the solenoid valve, by disconnecting that wire from earth. I speculate that your car has this system, and that control unit was playing up. The then owner discovered that earthing that wire solved the problem. My car doesn't have that overrun cutoff feature, and I don't miss it, so I would just make sure that wire is earthed properly and then forget about it. I don't know the arrangement on a 'rocco, but on a Mk2 Golf that green-ball bracket is clipped onto the scuttle metalwork in a way that I wouldn't by any means trust to form a good earth path.
Thanks, a control unit further diminishes my knowledge of Pierburgs I have already found a melted interior light wire and the car has had electric windows and central locking fitted post factory. I have removed a very poorly wired alarm also. I think I'll be fitting a Weber DMTL that I had previously rebuilt, more at ease with the simplicity of the manual choke and wiring. I appreciate that the Pierburg is probably the better carb but it's the variables of fueling contamination from the filler neck,tank and fuel lines that add to problems.
