Help!! - carbs are p*ss*ng petrol

[AirPower]

What could be wrong - the weber 36DCD's have a steady steam of petrol coming out of the main jets, even with the motor switched off. I checked the float chamber level and it's 31mm deep (the petrol level that is). Could it be too much pressure?
I thought the petrol in the float chamber would then have been much higher. Yet it pours out where petrol is usually supplied at "wide open throttle". The 2nd one has petrol coming out of the vacuum supply pipe as well.

Are these DCD faulty do you think. The petrol supply pressure is so low, the gauge I've got on there doesn't even pick up.

That's for the guy who sold me these DCD's (not a forum member).

[calooker]

Problem with these DCD's is that they can be made to work on just about any engine, so every man and his dog has had a go at them. 2 problems that I have had with other carbs and could be yours too, the needle & seat is shot or the the accelarator pump circuit no return is missing or stuck in the open position. It has been a long time since I disected a DCD.
The no return prevents fuel getting into the card when the accel plunger is not in opperation.
To do a quick check if you remove the top of the carb and give the base a good shake you should hear the thing moving around.
To check the needle & seat opetation turn the carb upside down suck out the air out thru the fuel inlet and then place your tounge over the inlet (using your tounge as a plug) it should hold pressure. If the pressure doesn't hold then the needle & seat is shot, just make sure there is no fuel in the inlet it tastes real crap.
Running high pressure elec. fuel pumps is a bad idea when running carbs, what are you running?

[AirPower]

Hi calooker

I've got an electric fuel pump but also a filter in there that reduces pressure to 2bar then I've got the cbperformance regulator with a return to the tank, this is set for carbs - like I said the pressure gauge no longer even picks up off the stop, first notch is 10kpa which it doesn't even reach.

[calooker]

You can also do a leak down test, remove the carb tops place some paper tissues on a table and get 2 small blocks of wood or tot glasses anything that will hold the carb over the tissues. Pace the blocks/glasses apart just enough to support the ends of the carb base and fill the bowl with fuel to the top, leave it for a few min or if you are patient you can sit and look for where the fuel may be leaking from. There are several plugs in carbs that if not sealing 100% or are missing will cause problems. I do this on all my Dellortos as the plugs do give problems.

[Tony Z]

uhm, if I remember correctly the Webers are happy with around 3psi which is 0.2 bar

[gazzapen]

2 bar. Thats too high for carbs. Used a 2 bar pump on my fuel injected Golf. We did the same on our carb 1.9 WBX panelvan and it leaked continuosly. Try get a low pressure pump electrical or mechanical and check. I think your problem will be solved

[AirPower]

The pressure at the carbs are < 0.1 bar (if 100kpa=1bar) - pressure is less than 10kpa

[AirPower]

OK - I've now taken off the DCD's and put on the IDF's. They've got no problem and seem to be fine.

I'll do that leak down test and rip them apart meantime - I MUST get the DCD's to work.

Thanks for everyone's time

[Tony Z]

IDFs also only like 3psi