110k miles on 1.4 carb engine. Frequently now (but not always) suffer 2 or three minutes really hesitant running from cold - actual starting is OK though, both from cold and from hot. Sounds like it's firing on less than all four, but clears itself and the problem never reappears after the car warms up. Plugs and lead and dis cap look OK. Replaced fuel and air filters about 12 months ago. Top of carb looks clean and none of the hoses seem to have leaks. Tail pipe is a bit sooty. Took it to (competent) garage a while ago before this problem started, and had them check it over because fuel consumption had climbed. They gave it a clean bill of health.
Where do I start? I feel this is a fuel / carb problem. The carb is labelled Bosch 030133023C, and my Haynes manual does not think that VW made carb-equipped petrol versions of this Golf!
The car is used almost always on short journeys, below 10 miles.
thanks
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Does it have an automatic choke?
On our 1990 golf there wass a device to open the choke flap when the engine has started, operated by a vaccuum pipe. The diafragm in this failed giving the same symptoms. It's called something like a vacuum pulldown unit. It was simple to change.
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Indeed, I think it does sound like the pulldown device/mechanism is at fault. The rough running is probably over-rich mixture because the choke plate isn't being opened by the pulldown unit, and then, as the engine warms up, the auto-choke comes off, and the problem goes.
If there is a diaphragm, detach the rubber pipe from lower down on the carb, and give it a suck, you should see the mechanism move, and feel resistance. If, however, the diaphragm is perforated, you will be able to suck lots of air through, feel no resistance, and observe no motion of the mechanism.
Number_Cruncher
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Yes it is auto choke.
Had a closer look at the carb - there is a small vacuum pipe coming away from the low part of the carb at just above the connection to the inlet manifold. And a larger pipe which goes away elsewhere. The small pipe connects to the underside of the air filter housing, into a small unit inside the housing made from orange plastic. This unit has a second vacuum pipe connection which goes to a diaphram mounted further along the air intake tube, ie further away from the carb. It looks like this diaphram is used to switch the air intake from either over the exhaust manifold or alternatively to come from a cooler point down away from the exhaust heat.
I guess this is not the diaphram you were referring to? When I blow suck through through this pipe nothing moves.
There is no vacuum connection going into the carb itself. The only controls are electrical - one plug goes into the top half of the carb, and two sets going into the main part which holds the throttle valve. None of these cables or plugs looks damaged.
Any more ideas?
thanks
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Hi, I had this problem with my golf, turns out there is about four or five things that are common faults with these carbs, what with pull down units, wax stats and what not, i put on a replacement twin choke weber carb which cost about £200. They are easy to fit (normally about 1 - 2 hours) and give more power and better response to throttle, also if driven carefully trying to use just one butterfly was better on fuel. The best thing is they come pretty much perfectly set up and i didn't have one more problem with the carb after that!!
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Forgot this part, also there is a flap in the intake pipe (the plastic tube that fixes to the airfilter housing) this flap is controlled by a vacuum. this flap will move the flap so it either pulls in cold air or hot air from the exhaust manifold, if this gets stuck on cold only will cause poor running and in freezing weather cause the carb to ice up!! Try and see if this in the cold air position you might need to wedge it into the hot position if its seized!! hope this helps
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