Mk2 Carb Help

[gavL]

Okay so this is the engine setup;
Originaly a GU 1.6,
Engine swapped out for a GU 1.8 running a Webber carb and K&N induction kit, manual choke.

The issues are the following
- After driving for 5-10mins it will then struggle to start again, but if just left on idle for any amount of time without driving it will start straight up without the choke.
- On a run it seems as though it is under fueling it's self and I have to drive with the choke out else it judders a lot (naturally MPG suffers)

I decided to rebuild it all yesterday as I've only just recently got the car and found no major issues but decided that I would replace the flange plate as it has some rough perishing around the edges and in the center, still the same issue.

The heat sensor that sits in front of the carb and is screwed on was also damaged so I've replaced that with a new unit as well.

Any advice would be appreciated.

Thanks,

[Diamond Hell]

Sounds like carb icing.

Stick the OEM inlet kit on it and make sure the carb heater is working.

[gavL]

What bit is the carb heater? The little black thing that sits on the front or?

As much as the current engine may hate to hear this I hate Carbs!

[gavL]

I'm at work at the moment.

I've found one vac line that comes out the back of the carb but isn't connected to anything I'm guessing this is the Hot air intake link.

Where does this connect to?

I replaced the black heater bit at the front of the carb (the bit you take of a Pierburg) with a better quality one yesterday but the problem was still apparent.

Cheers

[gavL]

http://www.clubpolo.co.uk/forum/index.php?showtopic=126734

Stumbled on this thread and turns out the pipe is meant to be blocked to force the hot feed to stay open?

[Cory]

sorry to steal your thread but im running a carb and am curious. i thought induction kits made no difference to a carb engine?

[Neo Badness]

Sounds like carb icing.

Stick the OEM inlet kit on it and make sure the carb heater is working.

Precisely what I thought, you can just run a suitable length of tubing from the crankcase breather to a suitable opening in an aftermarket filter.

[gavL]

Well something new has presnted it's self. If I drive with my heaters on full blast I can drive it all day with no real issues as far as ive found...

Going to try doing the hot air feed trick, but I think the lastowner removed the cover that goes over the manifold to feed hot air...

[Neo Badness]

Well something new has presnted it's self. If I drive with my heaters on full blast I can drive it all day with no real issues as far as ive found...

Going to try doing the hot air feed trick, but I think the lastowner removed the cover that goes over the manifold to feed hot air...

Work arounds are always handy but would be good to get to the root of the problem. Let us know how you get on.

[gavL]

Work around started failing..

Had to drive from Durham on the Choke and Clutch, put any power in above 2.1k and the engine hated life and would feel like it's going to stall unless I chucked in loads of revs.

I think I'm going to agree with everyone here and say its carb icing the problem is more prolific in the cold.