Help fuel supply question suspect regulator?

[nigellazypostman]

Hi I need to once again as you all for your advice.

The car broke down the other day with the AA recovery person advising it was a fuel pump issue. Sure enough I had power to the pump terminals and I could not hear the pump prime, so order and fitted a new pump and still the car will not start.

Whats odd is that under the bonnet I have zero fuel pressure at the Schraider valve, and the pump definitely primes then stops. When I slacken the lock nut off on what I think is the return on the fuel rail I have zero pressure or fuel, however there is plenty of pressure going into the fuel pressure regulator on what I suspect is the supply from the pump/filter.

Please can anyone advise what have I missed or what can I try?



Regards

Nigel

[buick boy]

I should replace the fuel filter as a start. I had one block on my old V70 and the symptoms were similar to what you're experiencing. I cut the old one open and found the innards had collapsed and blocked the outlet .

[duke1]

Originally Posted by nigellazypostman

Hi I need to once again as you all for your advice.

The car broke down the other day with the AA recovery person advising it was a fuel pump issue. Sure enough I had power to the pump terminals and I could not hear the pump prime, so order and fitted a new pump and still the car will not start.

Whats odd is that under the bonnet I have zero fuel pressure at the Schraider valve, and the pump definitely primes then stops. When I slacken the lock nut off on what I think is the return on the fuel rail I have zero pressure or fuel, however there is plenty of pressure going into the fuel pressure regulator on what I suspect is the supply from the pump/filter.

Please can anyone advise what have I missed or what can I try?



Regards

Nigel

hi it sounds very much like a faulty fuel injection relay found under the fusebox and no longer available on most sellers but i did get one from caffyns about £60 though,but this is a common fault and easier than fuel pump!

[nigellazypostman]

Checked tonight and have 90psi at the pipe going into the fuel pressure regulator but zero pressure in the actual fuel rail, surely this is pointing to a failure of the pressure regulator rather than the fuel relay as there is no fuel in the rail to be injected and to the best of my knowledge the relays fires the injectors, the pressure regulator has no electrical connection or link to the fuel injection relay. Totally appreciate any suggestions and clearly I don’t know what I am doing hence the question.

[Simmy]

check the cam position sensor i believe it sends pulses to the fuel system

[Luxobarge]

Originally Posted by nigellazypostman

Checked tonight and have 90psi at the pipe going into the fuel pressure regulator but zero pressure in the actual fuel rail, surely this is pointing to a failure of the pressure regulator rather than the fuel relay as there is no fuel in the rail to be injected and to the best of my knowledge the relays fires the injectors, the pressure regulator has no electrical connection or link to the fuel injection relay. Totally appreciate any suggestions and clearly I don’t know what I am doing hence the question.

I agree with your assessment here, that does sound to me like it's the regulator that's failed. However I have no experience of working with the fuel rail and regulator, just agreeing with your logic. If it were me I'd replace the regulator, even with a second-hand one if need be (they rarely fail so a used one is highly likely to be fine).

Cheers

[buick boy]

I agree with luxobarge . Definitely sounds like the regulator . They are fairly cheap to buy on fleabay , worth a try

[PSJVTHEBEST]

nigellazypostman was it the FPR? I would be interested to know if a normally reliable piece of kit failed in your instance.
Cheers.