Fuel Accumulator

[vitesse]

Anyone out there got a 40cc fuel accumulator ref 931 110 140 00 for a 1977/8 924 with metal /plastic injector fuel lines?

 

[vincematthews]

ORIGINAL: VITESSE

Anyone out there got a 40cc fuel accumulator ref 931 110 140 00 for a 1977/8 924 with metal /plastic injector fuel lines?

I think I've got the old one kicking around somewhere when I upgraded the system - I'll have a look.
Can't guarantee how much life its got though.

Also got an early fuel pump - NEW - which was bought by mistake.

 

[vitesse]

Vince -any luck with your look?

 

[vincematthews]

Sorry for the delay - eye off ball somewhat as daily driver and both Porsches off the road at the same time.
I've had a look now, found the fuel pump but no accumulator - I think I must have binned it due to its poor condition.

Not sure its worth fitting second hand fuel system parts or you might end up with the hot start problem?

 

[924nutter]

In the main the warm start problem can be resolved by replacing the check valve on the end of the pump outlet. When this lets by badly the accumulator cannot maintian sufficient pressure in the fuel line to stop under bonnet ambient from causing a vapour lock. Already discussed at length and in detail on this forum it is sufficient to say that the pump will only run when cranking the engine so it cannot quickly build up pressure to bleed the vapour lock out and open the check valve in the fuel injector, which is why fitting an auxilary earth return to the cold start injector will get the engine to cough, (a couple or three goes at that and it will fire up) The fuel accumulator helps to maintain a constant pressure in normal use. Without it the fuel pressure would surge when you have the indicators on for example as the pump speeds up and slows down according to the on off nature of the lamps, just over 3.5 amps (2X21 w plus repeater)

 

[vitesse]

Thanks for trying ,Vince--got my friend looking at VW parts people.

John--the problem is not connected to hot start-the car has only 1 -20cc accumulator -I 've upgraded the CSI distributor to the next version with metal fuel lines & it now needs the upgrade to the 40 cc version before I can move on to looking at the system pressure.

 

[vincematthews]

ORIGINAL: VITESSE

Thanks for trying ,Vince--got my friend looking at VW parts people.

I got mine from Motor Parts Direct; their part number (or maybe a Bosch number) was 0438170024 and was £116.79 inc VAT a few years ago.
Please check the part number against your car before ordering in case its no longer the correct one.

I also made, for £50 worth of parts from Stauff UK, the fuel system test rig like the official Porsche one.
It was really useful in checking pressures in the system and pressure decline rates after switch off.
I can give you a parts breakdown if needed.