mk 1 cab running issues :(

ok im hopeing someone may be able to shed some light on this for me!
i bought a mk 1 golf cabriolet 1.8 auto a couple of weeks ago and it runs fine and iv had a service done on it which has helped it as it hasnt been driven since september!
now like i say it runs, idles etc fine but then after i have been driving for a few miles it starts to judder and loose revs and then the revs keep going up and down.
if i pull over it doesnt cut out all of the time just sometimes. so if i switch off and leave it for a minute or two it will start straight away and then drive another few miles before doing the same again.
iv had the rubber mounting underneath the carb done today incase it was that letting air in, but it hasnt cured it
anyone got any ideas what the problem might be? reckon it could be carb rebuild time?
thanks in advance

crap in tank being sucked up.

the tank is ok.
iv just spoke to my friend and hes said it could be a block in the fuel lines so when the carb chamber empties after driving a bit, fuel wont be able to get through properly. hence why when i pull over the chamber will fill back up and then drive a bit further before doing the same again.
think im gonna replace the fuel lines before tackling a carb rebuild.

check the inline filter and check in the top of the tank under the rear seat with a magnet if theres rust in there the magnet will find it :wink:

Just had this problem for the last month or so at last traced today and fixed………..
 
The air intake has two tubes on the side:



 which I removed when servicing a month a go and cleaned up carb. I put these hoses back the wrong way round.
Switch them back today and it works perfect !

If any one is having this problem then please try this, not sure why this works! But it had been driving me mad !

I have the same issue and have not got to the bottom of it either. I am now at the new carb stage.
Replaced coil, ignition pack, leads, rotor arm, dizzy cap, plugs. Then been down the fuel line and replaced filler neck, checked all the usual  suspects, tank for rust, filters, swirl pot?, lines, replaced the fuel pump. The only thing left is the carb, Any ideas guys.

Adieiow said

Just had this problem for the last month or so at last traced today and fixed………..
 
The air intake has two tubes on the side:

 which I removed when servicing a month a go and cleaned up carb. I put these hoses back the wrong way round.
Switch them back today and it works perfect !

If any one is having this problem then please try this, not sure why this works! But it had been driving me mad !

Take this back it worked for a day back to drawing board still only getting about 10 minutes drive then plays up!

After reading haynes manual maybe this as a new possibility!

Cold valve sensonr opens to allow a bit extra fuel, at 16 degrees it cuts off.
Now when tuning if the car is not at 16 degree,s then this would cause fuel starvation once out on the road and it hits that magical 16 degrees.  :dontknow: