Fuel leak on Pierburg Carb Petrol 1.9 DG

[Sailsy]

Afternoon all.

I have had my van off the road on SORN for about 12 months and am in the process of getting it back on the road.

Engine started fine and it ran ok the other day so booked in for an MOT today. I had given it a good looking over and all seemed ok including the fuel lines etc.

At some point in the half a mile drive to the test centre the carb started pissing petrol out.  I didn't notice at 8 am this morning and only found out when the garage called to say I had a massive fuel leak and they had abandoned the MOT and pushed it out of the garage for fear of it burning the place down.

I went up and had a look and the fuel leak seems to be coming from the lh side of the carb (if you are standing behind the van).  At first I thought the fuel line to the carb had perished which on inspection it was very sad looking and split so I replaced it with a fresh length and new clips.  Thought I had sussed the leak but when I fired it up and ran to the back of the van fuel was still pissing out from the LH side of the carb but in the haste to turn the thing off because it was landing on the warm exhaust I couldn't locate the exact location of the leak.  I think it was coming from underneath the fuel inlet on the LH side but I only saw it for a second so I am not 100% sure. 

The van is a 1.9 petrol DG.  I had the carb rebuilt by Bromyard about 6 years ago.

The van is now stuck at the local garage (who now nothing about old Vdubs) and I cant drive it the half a mile home because it is leaking too much to drive. They are already talking about replacement carbs so I need to try and get it fixed before they start trying to.

Any pointers to where or what to check/look at next?

Thanks in advance.

Cheers

Andy

[Smiffo]

On the return line to the tank ( goes via left hand side of engine bay when looking from rear ) there should be a return valve.
It only allows excess fuel to flow from carb to tank direction.

I wonder if it is either in the wrong way, or faulty, thus unused fuel pumped into the carb has nowhere to go?

I'm not really carb-proficient, but I think the float in the carb should allow a needle or pin to block more fuel coming in too.
Easy the check that valve first though.
 

[Mocki]

The accerator pump is a thing you need tho check, you dont need the engine running, just work the throttle cable and inspect the accelerator pump
This new fangled LBGTQ petrol eats the seals

[Sailsy]

Hi Mocki

I thought that might be the area the fuel was leaking from.  Is it the rubber diaphragm which fails or is it a seal under the accelerator pump?

2nd million dollar question is can I replace it with the carb in situ?  The van is locked up in the garages compound for the weekend but I can get down there on Monday to check if it is the pump.

Cheers

Andy

Ps. One redeeming factor in all of this is the van didn't combust with all of that petrol dropping on the manifold and exhaust....

[Mocki]

Yes you can do it with carb on engine, its a ten min job with this
https://brickwerks.co.uk/product/carb-r ... rburg-2e3/

[Sailsy]

Update on the leaky carb.

Been down to the garage to get the old accelerator pump diaphragm off the carb to check its size and it appears to not have a spring underneath it like it should do.  

Not sure where I can get one because it isn't in the rebuild kit.

Any help most welcomed.

Cheers

Andy

[Mocki]

Has it ever run?? I doubt it would without the spring ……. As re you are its not just escaped??

[Sailsy]

It had escaped and was hiding under the cloth I used to mop up the dripping fuel......