Hello All, I appear to have messed something up on my Mk1 Golf with twin Dellorto 40's on it. I took the carbs off the manifold so I could drill out the vacuum take off on the manifold for the brake servo. That went well and I was very careful to place the carbs to one side, just disconnected the fuel pipe but left the accelerator linkage attached and didn't adjust any settings on them. Anyway, I put it all back together and turned the ignition on to prime them so I could have a look for leaks. The car has an electric fuel pump fitted and what normally happens is that you turn ignition on, hear the pump prime (presumably fills float chambers? I know nothing about carbs!), pump the accelerator a bit and then it'll start. Well, now you turn ignition on and the carbs fill up with petrol and then excess petrol pours out of the trumpets (is that what they're called?) on the right hand carb as you look at the engine bay. If you look with a mirror down the trumpets then the left carb is ok but the right one seems to keep spraying fuel and overflowing, that's just with the pump running, not the engine started? What have I done? Is there some sort of valve that should cut off fuel when float chambers are full or something? Everything looks in order and I didn't adjust any screws/linkages/cables or anything? The throttle linkage seems to sit where it should against it's stop so it's not holding the butterflys open or anything? Help! Pic for reference.... By the way, haven't tried starting the car as there was too much petrol around, didn't want it to go bang! Cheers Stu
did you make sure the lug on the throttle lever was put back into the adjuster bit for synchronising the butterflys when you put it back together? if not then one carb will have a closed throttle position and the other will be open quite a bit, and would let fuel through i think.
doesnt sound good mate, something must be stuck open, the throttle linkage looks bent maybe that the problem , or your a cable short.
Thanks for the replies Yes, the linkage/balance thingy between the two carbs is ok, I made sure to check that and the throttle linkage although a bit wonky is back how it was before I started messing so don't think it's that. I think there is a valve stuck open as Mk1 says, I will take the top off the right hand carb and have a look, hope I don't make it worse though, not really a carb expert by any stretch of the imagination, oops! Perhaps I have disturbed something in there when I was jiggling the carbs to get them off the manifold?
Did you turn the carbs upside down when you moved them out of the way ? Undo the 4 screws that hold the main carb top on (not the small square one in the middle held on with 2 bolts) and "carefully" (there's a gasket between the top and the main body) lift up the top until the float (attached to the underside of the carb top) clears the main body. The float should fall (pivot) down slightly, check that the needle valve is'nt stuck (you'll find it between the back edge of the float and the carb top).
Carbs As Mr Hillclimber says the float needle isn't working as it should. Its a simple device: fuel comes through a drilling that has a taper that opens out at the end in which the needle sits - the end of this has an opposite taper, the pressure of the fuel pushes against the needle allowing fuel into the float chamber. As the fuel level rises so does the float which the needle is attached to pushing it into the taper. So eventually the pressure of the float rising forces the needle into the taper cutting off the fuel. In reality as the engine is using fuel it never actually cuts off the flow but regulates it. But if there's any cr*p on the end needle it won't seal or maybe the needle has come adrift of the float when you've moved it. Should be easy to sort. Barkstar
Also, if its dumped that much neat fuel into the cylinders then whip the plugs out and crank the engine over to get the excess fuel out (make sure nobody is standing in front of the car !). Once you have it sorted it would'nt hurt to change the oil and filter, you may have had a load of fuel run down the bores into the sump.
Hmmm... yes, I think you may have hit the nail on the head there, I tipped them up jiggling them past the various linkages and cables and stuff, that must be what's messed it up. Excellent advice, I will investigate today hopefully and report back, hopefully nothing too drastic gone wrong then!
Thanks for all the help everyone, I think it's sorted now! I carefully took the top off the right hand carb and the two floats are on a mechanism attached to the carb lid, as described by a few people above. Anyway, all seemed to look ok so I just operated the float mechanism by hand a little bit and then carefully put it back together. It must have just got trapped or stuck somehow from my messing around. Turn on the ignition, pump primes but no excess fuel spraying everywhere, jobs a good 'un I think, starts up fine and back to normal... well, as normal as a 30 year old 3-speed auto hatchback with two whopping carbs is ever going to be... There does seem to be a little leak from the manifold or carbs somewhere as when you rev it there is a bit of smoke/steam/exhaust gas (?) flying around in that area but I wonder if it's just spilt oil and petrol burning off the exhaust manifold? I will check everything is tight once it's cooled down. Also, still not very impressed with the brakes (remember, the brake servo is where this all started), the servo is now getting a very stong vacuum to it but the brakes are still rubbish so will need to investigate further. I will give the discs, pads, fluid, handbrake adjustment etc a once over and see how that goes, I know from experience Mk1 brakes aren't the best...
Yep, carbs sorted thanks Brakes, well, they seem poor even by early Golf/Polo standards that I've had before, no real bite to them and the pedal feels like pressing a block of wood really I notice the front calipers and pads are different to the later ones and have very small (like the size of a postage stamp) pads, plus the fluid is well past it's best. I will give it an overhaul and see how I get on.
Glad about yr carbs. Sounds like a fluid change as a starting point (simple dot 4 or 5), any idea what pads are in there ? Brakes on mine were just like yours when i got it, pad change made the world of difference (1144 mintex back then), but any decent branded road pad would probably suit you ok. If the disc face is like an old record then change them as well.
