Pump & PRV

[simon.williams]

So, by a process of elimination, I believe my cutting out is due to the fuel pump/PRV, and not the metering unit, coil or air intakes (grrrr!). Not sure what exactly the problem is, but the pump starts to make a high pitched whine or mewling when at idle, as if it is working too hard, and then the pipework around it seems to "clench" as if pressure is being released and the noise disappears, only to build up again.

I don't know if when idling fuel should be just recirculating in the system. My guess would be the pressure release valve is set "too high" or "not high enough".

Somehow the fuel pressure is not getting through to the metering unit when it is in this "mewling" state.

Getting closer though! I can email a short video if anyone kind enought to attempt a diagnosis. The Pump has clearly been getting very hot and lubricant has leaked from it...

[Charles H]

Personally I would talk with KMI injection and perhaps firstly get an exchange PRV as a start.

[simon.williams]

Thanks Charles I have reached out to them. I’m pretty sure its the PRV…

[Mike Stevens]

Simon,

We're back to Normandy next week, Shall I pack the fuel pressure gauge?

Cheers, Mike.

[simon.williams]

If its not too much trouble Mike, but let me pay for any postage. Where abouts in Normandy are you? We are often in the Cotentin so I can drop it back en-route if you are there reasonably frequently.

Thanks very much

Simon

[Mike Stevens]

Simon, replied directly to your email address.

Mike.

[Alec]

Hello Simon,
I don't know if you have gone further (I've been away for a week) but a noisy pump is more likely due to lack of fuel supply, not an over pressure due to the PRV set too high.

Alec

[Mike Stevens]

Have you checked/replaced the fuel filter?

Cheers,
Mike.

[simon.williams]

Thanks, took everything apart this weekend, drained the tank. Couldn’t find a blockage, was able to blow through everything. Might have had some « varnish » floating around in the petrol in the fuel filter, but nothing seemed clogged. Will fit a new filter just in case.

[simon.williams]

Chris Witor thinks it could be the pump « cavitating » against the pressure relief valve. Having drained the tank (twice) and blown through all the pipes, I think its the last possibility. New PRV on order….