Ive searched and couldn't find anything.

Has anyone measured the volume of returned fuel with a standard fuel system.

Figures for different engine speeds would be useful.

I’d like to know the answer to this as well. On my car, at idle, it’s gotta be close to a pint a minute. Much more than I expected. I’d also like to know if it all flows through the filter or is bypassed before being returned to the tank.

Thanks, Geno

quote:

Originally posted by Turbogeno:
I’d like to know the answer to this as well. On my car, at idle, it’s gotta be close to a pint a minute. Much more than I expected. I’d also like to know if it all flows through the filter or is bypassed before being returned to the tank.

Thanks, Geno

All of it flows through the filter, the air bleed in the banjo is quite small. And the return flow is more than a pint a minute. When I looked at mine, it was closer to a gallon a minute, and that was at idle.

Wouldn't it be LESS under load, or at higher revs?

240,

Engine turning faster so the lift pump will be pumping faster... I guess it would be more at higher rpm but slightly less at high load same rpm.

UFO

Thanks for that info - helps a lot.

Long largely offtopic explanation follows (some info may be useful to SVOers)


I've got a Hymer camper which uses a OM 616 engine on a Mercedes 307D chassis (predecessor to the sprinters)

I found it for a X-girlfriend when she was not my X about 8 years ago. Earlier this year it conked out on her and she had to be towed home.

She occasionally put a bit of new rapeseed oil in the tank. Generally as a mix.

I only heard about this after a mutual friend had been working on it - he doesn't often work on diesels - he tried a filter change then decided the injection pump was at fault.....

Injection pump rebuilt and refitted - no improvement. He got a friend who works as a mechanic to help - they got it running fine drawing fuel from a can but when he reconnected the pipes to the original tank it died again.

I suggested it was a problem with old hoses or junk in the tank. She neaded to move it, ran out of time to get it fixed it and gave it to me

I had it put on the back of a truck (for an amazingly cheap price) and brought down to one of my yards.

I disconnected the fuel pipe from the lift pump inlet tried sucking the fuel from the tank using a 12v gear pump I have - http://trueasset.org.uk/index.php?page=pumps
Loads of air being sucked. I slowed down the flow by restricting the outlet flow from pump with one of my nice adjustable stainless hose clamps (..... think it was a surgical clamp once) at 1 litre a minute it stopped sucking air.

So I dropped the tank, disconnecting the short, I guess, original rubber hoses that connect the tank to the nylon pipes and took the sender/pick up unit out the top. Tank was clean - a bit of dirt on the gauze strainer (which I did not refit.) but not a lot considering the van is almost 30 years old.

This unit is a big tube which houses the float for the level gauge and the pick up and return pipes.

Refitted the pick up and tried sucking fuel with my pump connected directly to the tank - with same results as before.

I'm going to pull the tank sender/ pick-up unit apart and see if I can spot a crack in the pick up tube.

I'm now fairly confident that this is the problem. I'll update later....