Fuel accumulator

[cello297]

I understand that the fuel enters the accumulator by one of the junctions at the top of the accumulator and leaves by its neighbour, but can anyone explain to me where the third (bottom the way I look at it) pipe goes? Is it a return? in that case where does it return to?

I have re-fitted the three units on their tray, using the original holes and they rub firmly together, which I am sure they shouldn't. Any useful thoughts, or am I laying myself open to the usual ridicule?!

Yet again thanks for input including the silly ones...

[Wedg1e]

On my Tasmin the fuel pump was mounted on 3 or 4 small rubber insulators, so it stood about half an inch off the plate: maybe it would make a difference if the insulators (for noise and vibration damping) were missing...?

[cello297]

New ones fitted. Perhaps I got the wrong ones as they seem big for the job???

[cello297]

Trying to get an answer if anyone can help: where does the third (single) pipe go to from the accumulator?

Sorry to be awkward, but the re-build is stalling for one or two small (?) items. Frustrating, 'specially when we are working in these temperatures!

Thank folks - or even just one folk. Shane

[mrzigazaga]

Hi mate..Ive got a 280i DHC 1981 and i beleive mine is as described in the capri manual..Although the pic only shows and mentions two feeds..One coming from fuel pump and two going to fuel filter..The first function dampens any pulsation of fuel flow from pump and the second maintains fuel pressure after engine has been turned off..This prevents vapour lock developing with consequent hot starting problems..Hope this helps..sorry if it dont..Zig

Edited by mrzigazaga on Tuesday 7th December 19:07

[MJG280]

My Haynes Grandad manual shows two fittings at one end and a single at the other. The two comprise the feed from the pump and flow to the fuel filter. The single is an air return to the top of the tank so looks like it is there to accommodate air movement following movement of the diaphram

Having written the above I remembered I had a scanner!!

[jeff m]

I have a couple of scans of the fuel system.
One has two hoses, in from the the pump and an out.
The other which I shall post below shows a third hose from the back of the accumalator that goes back to the tank. A sort of return, I've no idea why it would have this as the purpose of the accumaltor is to maintain pressure in the fuel system.
Another "hole" would defeat this.
Although I expect the third hole is the pump side of the springy bit inside.
I would not have though this neccessary as the fuel pump has its own little valves and any excess pressure just flies around inside the fuel pump (so to speak).
Anyway the guys who designed this are a lot "cleverer" tham me, so here's your pic


I expect there is a valve of some sort or a constriction or the gas would take the path of least resistance back to the tank.
PS the other scan I have shows no hose from the rear to the tank. I guess the hole is blocked ( I suspect you could block yours, Depending on the pump I guess. good luck)

[Wedg1e]

Have a shufty here:

http://www.diagnostic-assistance.co.uk/mech_inj.ht...

Shows a pipe stub to the rear of the accumulator, ie the non-fuel side. My theory is this: the stub is a vent that has to be there to allow atmospheric pressure to the non-fuel side of the diaphragm (otherwise a vacuum would be created as the spring pushes the diaphragm into the fuel, negating the point of the spring!).
If the diaphragm were to rupture, fuel would piddle out over the floor/ rear tyres/ discarded fag ends... so the pipe back to the tank acts as a safe drain for leaking fuel

[cello297]

Fantastic! I didn't realise I had so many readers! This - no, these - are a great help. To be honest I had no idea what a fuel accumulator was until seeing this one!

Anyway, most grateful. You truly might see the Tamsin out next Summer. Seems like forever, but it is coming together, mainly due to Ruari's input. He has a well deserved share in this project and the car.