fuel pump/non return valve

Is it possible that different fuel pumps can have integral with them, a non-return valve. I recently replaced my fuel pump, previously (running problems aside, which were related to the muck in the system) it started fine. But with the new pump, the 'first' start of the day results in around 30 seconds of turning over before any sign of firing up. So it seems like the old pump had a non-return valve but the new one doesn't?

It looks like there is nothing which is screwed into the old pump, which I can unscrew and transfer to the new. Can you buy a non-return valve, which might possibly screw into the new pump?

Paul if you are cranking for 30 seconds i would rule out fuel non return valves . Providing the pump runs when the ignition is on and before cranking , fuel pressure will be okay it's when warm problems arise . Eg loss of residual pressure .

Time to look else where   :dontknow: Follow basic checks remember the ignition  :wink:

Keep us posted ……..

What make is the new pump? I think Pierburg ones have a built in non-return valve and are slghty longer as a result?


Cheers

markwon said

What make is the new pump? I think Pierburg ones have a built in non-return valve and are slghty longer as a result?


Cheers

I don't know, I'll have to look out the box or take it out of the carrier and have a look at it. The end (where the high pressure fuel fitting goes) was slightly different, but I couldn't see any extra parts attached. The new pump was thicker than the old one, too; the old one had an inner and outer rubber carrier, so I could use the outer carrier with the new one and not worry too much about the other one.

My new Pierburg pump (3 months old) from GSF has the valve built in and is thinner than my old Bosch one.  The first time you use it it will take a while for the pump to prime the system to the correct pressures and get rid of any air in the system.

If the non return valve was faulty the car would stop instantly and not start again until the pressure in the system had been released.  I had this problem and had to wait at least hour before she would start again.  As Chudd suggested I would rule out the return valve as a problem.

Cussco

The new pump is a Bosch, and is thicker than the old one, so its definitely a different make or model. Anyway, I found the old pump and there is a valve at the end, which I may be able to swap over. I still think its pump-related, since the problem only started after the pump was swapped. I think (from memory, a couple of weeks ago now) that the new pump came with a similar fitting in the end of it, maybe it was a 'dummy' piece the same size and shape as the valve, but not the same function. I thought that some pumps had the valves built into them, while others needed a little valve on the end of it?

By sheer chance, another car of mine (non-VW) had a similar problem, where this valve was leaking and needed to be replaced!

The Bosch pump will need a seperate screw-in valve 893 906 093 and a dome nut N 011 069 1, about ?22 from VW. Thinner Pierburg's have a have a built in one.

Cheers

markwon said

The Bosch pump will need a seperate screw-in valve 893 906 093 and a dome nut N 011 069 1, about ?22 from VW. Thinner Pierburg's have a have a built in one.

Cheers

Nice one Mark, I'll sort out these items and fit them when I've next run down the remaining fuel in the tank. I might have a little experiment/look at the existing fitting I have, in case its this part and I'll save buying parts twice.

Thanks!

No problem, had to replace mine recently as was leaking. You need to take the pump off to fit it and stick couple of copper washers either side of the hose union.

Cheers

Bit of a hijack here but what is the quality of the pierburg pump like? I have just got one from gsf - even though I ordered the bosch one (they have 2 listed on the site, one half the price of the bosch). Just wanted to make sure that they haven't sent me the cheaper one by mistake…

Thanks