Mk1 k-jet fuel accumulator failure?

[richandhazel]

Anyone ever had one of these fail? If so, what were the symptoms?

Its the last thing I need to test before condeming the fuel pump, however I have never had an accumulator fail.

[Madone_si]

Hi Rich, I can say I've never had accumulator fail on me, what issue you having at the moment?

[richandhazel]

Its Victoria's mk1 Golf GTI. I'm 95% certain its the fuel pump thats at fault but as Victoria isn't in a hurry, I'm willing to spend just a little more time.....just to be sure.

The fuel pump looks like it has been replaced, not soooo long ago, but who knows.

Its already blown a fuel pump relay fuse and subsequently the relay and all the wiring to the relay shows signs of overheating. Sure enough, current draw is around 11 Amps. Way to much. Cracked the fuel line to the filter and placed it in a jar: 5 amps. Cracked the fuel line after the fuel filter: 5.5 amps. Put it back together and as the pressure builds, amperage rises to 11 amps and fuel pump stops. Its not getting up to enough pressure for the fuel to return to to the tank..........or the metering unit is not allowing the fuel to return to the tank once it has achieved 65/75 psi or above. I'm sure there is nothing wrong with the accumulator and the fuel pump inlet is clear. I shall pressure test the metering unit tomorrow and if that is returning to tank then that should confirm it. 

[richandhazel]

Carried out a pressure check on the inlet to the fuel filter and therefore the metering unit this morning. Pressure started relieving back to the tank at exactly 52psi so I now know that there isn't too high a build up in pressure. Going to drop the fuel pump out and just verify that the fuel line through the accumulator to the inlet of the fuel filter is clear and then its its off to GSF for a new fuel pump and filter.

[Dinky]

hope ur gettin well paid love..sounds like a full on job u got there!

Dinx

[mk1]

Hi Rich,
deffo sounds like the pump, the accumulator only stores pressure and has no bearing on the pumps current draw. Have you checked the amps drawn with the pump disconected (you will have to jumper the relay) as there are some engine cold start components fed from the pump relay ie.. warm up reg and cold idle bypass valve.
Steve.

[richandhazel]

Hi Steve,
Yeah those current checks that I carried out were without the relay connected. As you say, I made up a jumper to directly connect the pump (via my ammeter) to the +ve on the relay base plate. Having fitted the replacement pump, the current draw unpressurized is now down to 3amps and pressurizes to around 6 to 7 amps. Still quite high but a lot better, it continues to run once system pressure is achieved and runs a lot quieter.

I asked about the fuel accumulator as I have never known one to fail, but then there isn't really a whole lot to go wrong with them is there. Is it just a piston and spring in the accumulator or is it gas sealed too?