Fuel Drain

[Pintogogo]

When I leave my S7 running a 2.0 pinto the fuel drains from lines and will only start after pouring petrol into top of carb, Ive tried :-

Fitting new OE mechanical fuel pump

Moving in line filter before and after fuel pump

Fitting non return valve before fuel pump

Replacing fuel line

Blowing back through line to clear tank filter

Just ran out of the dead can anyone help

[richyb66]

Do you have the plastic spacer fitted between the carb and the manifold. It reduces the heat soak to the carb that causes the fuel to evaporate. They're normally removed to increase bonnet clearance.

[Pintogogo]

Cant see a spacer between manifold & carb but Ben like that 3 years but problem only been there couple of months fuel appears to be raining back not evaporating

[kevin the chicken]

I suppose you end up churning the engine over and over until the fuel gets there every time. I have had similar problems on a totally different vehicle and tried new fuel pump seals and non return valves neither of which worked. The conclusion that I came to was that the only sure way to cure the problem was to fit an electric fuel pump either alongside the mechanical ones just to prime the system or to replace the mechanical ones altogether. Just reread your post, do you mean after it has stopped for a while the fuel drains down? I don't know why those non return valves don't seem to work, are you sure there isn't a leak at the carb. Should be enough in the float chamber to fire it up. I run webber 45s and it will run for a minute or so with the fuel pump switched of before it starts to cough.

[Guest Hawaii Steve]

I’d probably try running the engine and then shutting it down and pinching the fuel hose with some vice gripps just before the carb. Let it sit for a day and then see if you have the problem. If you do it confirms a carb leak issue.

 

Steve

[agent_zed]

my 2b with pinto does similar. If i haven't driven it for a while i have to crank it for ages to pull fuel through. Not sure why. although i do get a bit of overrun occasionally. Does your carb have a cut off solenoid? perhaps that isn't seating correctly might be worth a try as it could be allowing the fuel to syphon back to the tank and pulling the fuel out of the float chamber somehow.

 

actually i should have a look at mine now I think of it

[MarkBzero]

The non-return valves in the mechanical pump deteriorate over time and break up or scum build up causing leak back. Personally I would blank off and get electric pump.

[Pintogogo]

Hi guys thanks for suggestions, Its a brand new mechanical pump that's fitted and pumps fine, there are no spacers between manifold and carb and there is no solenoid, so still trying lol

[gaz0571]

could also try running it with petrol cap of to see if the tank is vacuming