VW Scirocco GT2 1.8 carb running problems

[rumpelstiltskin]

Mate of mine has some problems with his Scirocco 1.8 GT2 Carb model.First problem is it needs the throttle down to start when hot,second problem is it will sometimes cut out when going down the gears,usually on a slight decline,generally the car feels underpowered!This has been driving him nuts and no garage has got to the bottom of it!Here's what he's had done to try and get to the bottom of it,deep breath...It has a replacement Weber freshly rebuilt with rebuild kit,new fuel pump,fuel filter,coil,plugs,leads,tappets done,alternator,rotor arm,dizzy cap,basically most things that would cause running problems!Anyone any ideas?Small reservoir between pump and carb has been cut out the equation too!

[speedtwelve]

Has he renewed the gasket between carb and inlet manifold? My Rocco GT-S ran like a bag of nails until I discovered a split in this rubber gasket, leaking air.

Roccos are also notorious for crap in fuel/corroded fuel filler pipes. Any build-up of crap in the fuel filter?

[aka_kerrly]

speedtwelve said:

Has he renewed the gasket between carb and inlet manifold? My Rocco GT-S ran like a bag of nails until I discovered a split in this rubber gasket, leaking air.

Roccos are also notorious for crap in fuel/corroded fuel filler pipes. Any build-up of crap in the fuel filter?

what i was thinking.
A rotten fuel tank filler neck will create a good build up of rust in the fuel tank which will block fuel lines. Have you got a clear plastic in line fuel filter in the engine bay- worth watching to see how many particals are in the fuel.

I also suggest close inspection of all the vacuum lines in the engine bay as these little buggers rot away and can become brittle and snap/crack. You can buy the hose from VW for couple quid a metre and it is very worthwhile to replace these before buying more expensive parts on the off chance.