Old car cutting out, needs high revs to keep going

[Steve01245]

Hey guys, my car is:

VW Golf GLS
1981
1.6 Carburettor
Automatic

It had recently started to cut out while at idle, needing to be revved up constantly to keep it running, and also while diving at a relatively low rpm around town would still try to cut out. I replaced the fuel filter as it was FILTHY (brown with rust coloured bits), and took it for a drive tonight for around 30 mins and it ran fine, so that's great. But the new fuel filter already has crud in it, after such a short drive. I'm thinking there may be a problem deeper down the line, rust in the fuel tank maybe? or maybe just stuff still left in the fuel line.

I'll show a picture of the new filter after just 30 mins of driving. Would love to know if this is normal or not, maybe I'm over thinking it. Thanks a lot for reading, Steve.

 

[Nozzle]

Your filter is working, huzzah! Being a carb, with associated low pressure fuel system there is no return back to the tank (unlike a fuel injected car). This means the fuel gets filtered only the once, and the tank is therefore not recirculated. I guess there could be some water in the tank? The fuel floats on top, pushing the water to the bottom and rotting it there. Unless your tank is showing signs of leaking, leave it be! (But change the filter regularly)

Nozzle

 

[DaveHerns]

Don't VW Golfs have a problem with the fuel tank filler neck corroding and rust flakes getting into the fuel ? I'd think you may want to see if rust has got into the float chamber and/or the idle jet

 

[Burnerman]

With the filters getting into that state you can guarantee the carb will contain similar debris and I'd recommend a strip down.
Certainly VW had problems with tank filler necks corroding and leaking around that time.
John