What's a Fuel Damper?

[oldgeebee]

Having removed what is called a Fuel Damper (according to the TVR Fuel System parts list - part no. S29L10043) from the inlet side of the fuel pump I'm not sure if this is working correctly or not. It appears to be a straight through feed but seems to have a rubber diaphragm inside.
Does anyone know what this part does and how it works?
GB

[Gerald-TVR]

I too was confused by this thing, all I can assume that the 'rubber cushion' just dampends down any fuel pulses from the pump to ensure there are no fuel surges

[GreenV8S]

The only fuel damper I'm used to is in the fuel rail and absorbs the pressure pulses when high capacity injectors turn on and off. I'm not aware of anything like that being fitted on the pump inlet. If you have one, the only purpose I can guess is to prevent pressure pulses from the pump from passing back into the tank. But I can't imagine why anyone would bother doing that or what problem it would solve.

[Gerald-TVR]

Hi its clearly shown in the official spare parts list (cant post a pic as i'm on holidays in sunny spain 14 days unbroken sum aver temperature 30 deg about to jupm into pool)

[jwoffshore]

The 2.8 cars also have a fuel damper (accumulator) fitted which is a standard part of the Bosch K Jetronic system. Described here http://www.auto-solve.com/mech_inj.htm

If yours is a 2.9, there is still a small damper unit. I've seen these on non-TVR cars too. Whether the damper is fitted directly after the pump or at the inlet to the fuel rail, I suppose it's going to have the same effect in smoothing out transient spikes in the fuel pressure. TVR fitted it at the back of the car where it is subject to a harsh envioronment, but you could move it forwards to the engine bay.

oldgeebee - did you say it's fitted on the pump inlet? Perhaps you mean outlet?

[phillpot]

jwoffshore said:

oldgeebee - did you say it's fitted on the pump inlet? Perhaps you mean outlet?

No they are on the inlet, that's why nobody seems to know what their purpose is

[oldgeebee]

phillpot said:

No they are on the inlet, that's why nobody seems to know what their purpose is

That's exactly right - fitted on the inlet side, as shown in the TVR parts list drawing. Just seems like an expensive 90 degree joint to me!
GB

[jwoffshore]

So it is! Just checked under my dormant S3 and it appears to serve no purpose other than an elaborate 90° elbow.

In fact, the fuel pump is poorly located and subject to a lot of road muck. On the V8S, the body at the bottom of the boot is altered to make a small compartment to contain the pump behind the tank and the fuel feed to the pump is a direct pipe with no "damper".