Club 80-90 Forums

Hi, writing this on behalf of her indoors, she owns a 74 beetle which starts fine but wont idle and cuts out when stopped, ie at junctions.
Has had new plugs, points, coil, condenser, dizzy cap, rotary arm, HT leads, manifold heater, regulator and oil change.....thinking it could be the carb, any suggestions?

murf

Could be idle jet blocked on carb. Turn in idle screw and count how many half turns you have to do, then remove screw completly. Clean needle and check jet isnt blocked by poking a thin length of nylon line through the jet eg. fishing line. A thin piece of wire can do the job but be careful that it isnt a tight fit through jet as this could enlarge the hole and make idle hard to adjust. When happy all is clean, turn idle screw in a couple of turns, start engine and increase revs to about 2500 rpm. Place hand over air inlet on carb while running and leave untin engine stalls (about 3 seconds). This will allow the engine to suck out any blockages that still may be present. When done, turn idle jet in until it just seats and undo to original position by counting out how many turn you counted in at the start.

Other than that it could be an air leak on the carb itself. If this problem only just happened then it is probably just a blockage but if it has been slowly getting worse over a few months then it could be a worn carb.

Check all hoses and vaccuum lines to ensure a tight fit.

I dont think these have a cut-out solenoid but if they do, ensure the wire is connected and that the solenoid clicks when ignition is turned on, otherwise fuel will not flow through the idle circuit and will stall the engine when the throttle is released.

Good luck, tell us how it goes.

Is the fuel shut-off valve working? Has anyone tried adjusting the idle? If they have and shut-off valve is working, they may have adjusted wrong screw.

On the lhs of the carb there is solenoid valve (I think it is called fuel cut off valve in the manual) on yours it will have a black wire and spade connector on the end of the body of the valve.

with the ignition on check that you have 12v supply at the connector on the valve. If you have the valve may be faulty.

Test the valve by leaving ignition on and touch the spade connector against its terminal- you should hear a tapping noise coming from the solenoid itself. If not valve isn't working. - Clean up and retry or replace.

Most of the time it is just a loose connection on this valve- crimp up the spade connector.

Have had this problem several times on T2 and beetles

Hope this helps

carb freezing ?

also check the rubber boots between the cast ally parts of the manifoled and the tubular bit the carb bolts on to, these can crack with age.

Ooh my bug did that, & we ended up putting the old cap & coil ect back on as it all seemed to 'fit' better.

Am i allowed to post a reply if i can't help?, just want to wish you the best of luck, i wrote mine off in the end so no longer an issue!

If its only started since we have been getting cold weather I would say that it sounds like carb freezing as guz said.

you can get inlet manifold de-icing units which keep it ice free...

Poseidon wrote:If its only started since we have been getting cold weather I would say that it sounds like carb freezing as guz said.

you can get inlet manifold de-icing units which keep it ice free...

Doubting its icing if it happens straight away, and the only problem is no idle, icing will usually start to affect the car after about 30 mins to an hour and it will bog, falter and stop altogether from experience.. You can check by running if for a while with the air cleaner removed and see if the venturi in the carb gets icy.. if so, then you need to clean the pre-heat pipe (or whatever) or fit an IMDU.

If its only doing it in cold weather... has anyone actually checked the operation of the choke?!!

Sounds like the engine isn't getting enough of the juicy stuff to keep it running when an enriched mixture is needed in cold weather.

I`ve had a few Beetles over the years,i think its an air-cooled cold weather thing,i used to give myself 5 extra minutes and get it warmed up a bit seemed fine when it was a bit warmer.

Hi all

have tried all of the extremely helpful suggestions above but have ended up fitting a new carb.....sweet as a nut ! , many thanks to all who replied, much appreciated


murf

Owned and maintained bugs all my life and 9 times out of ten its the throttle shaft letting in air. Any wear here and it'll die at junctions and idle like a pig.

Simply dying when coming to a stop at the lights is invariably a weak mixture. Just for the record.

CovKid wrote:Owned and maintained bugs all my life and 9 times out of ten its the throttle shaft letting in air. Any wear here and it'll die at junctions and idle like a pig.

Simply dying when coming to a stop at the lights is invariably a weak mixture. Just for the record.

...........or the auto-choke coming off before the engine is properly warmed up. I remember back in my Beetling days (1975-81) trying to brake & blip the accelerator at the same time otherwise the engine would cut out at lights/standing traffic etc.