Fuel Pump Issue

[david49west]

 I have the late 2.8 diesel 2007  

 The motor will only start if I prime the button on the filter housing up to a hard button

 I have change the housing and the filter

 

 What I would like to know is there a lift pump in my tank 

 should I be able to here a pump running when I turn on the ignition

   

 having lots of conflicting answers

 

 

          cheers dave

[QinteQ]

Good glad you're sorted Dave. To help your understanding on your model all the work is high pressure vacuum suck not blow as in a electromechanical fuel pump in the tank. At that point there is enough [#5 having just enough fuel in stock up front ] to start the car. If you get any air in or a vacuum out that displaces pressure and fuel. If your car starts and runs with the use of the primer button you have as you have found just that  air in or a vacuum out on your low pressure side.

[scrufgp]

hi dave i had similar problem but my car was cutting out while driving and wouldnt start etc......

i sent mine in for diagnostic to diesel specialist  

came back with fuel rail pressure release valve

had that changed not a single issue since

that was after changing every filter and housing and having the tank cleaned out !!!!

i know its not best to hear but send it to a diesel specialist !!! well worth the money  

[GVCamper]

Have you done the key dance to get codes in the cluster?

Mine showed fuel pressure too low/high code which is p1130.

I changed the pressure release valve at the end of the fuelrail which solved everything.

Its a bosch part which can be had at ebay for a okay price and a real simple job as its right under the plastic cover on top of the engine and screws right out.

 

Just remember to pressurize the system with the hand pump before starting it.

[david49west]

     Ok thanks for those pointers

 

    Since the post Ive removed the tank and there is no pump in there just a housing that holds the fuel gauge float

    I have all ready changed the valve in the fuel rail

    I will point out that the motor has never cut out once running

 

    I expect that the pump must have a suction side to it as there is no lift pump , and I expect this side of the pump

    is failing as the problem got worse and harder to start with priming ,

 

    I have rebuilt this engine so most of the stuff has been checked

  

    ill change the pump tomorrow ill report back

 

    thanks again for all your help

[QinteQ]

Screw on filter 0 ring bad or an idiot has put x2 0 rings on [happens all the time]

Screw on white plastic water trap on the end of the screw on filter [see below] has rattled loose [happens frequently] allowing air into the vacuum

Screw on filter itself is full of crap and will not allow fuel to pass at LP

Whole plastic housing is cracked allowing air into the vacuum

Check pipework for cracks

 

You have an Low Pressure part and the High Pressure part, the HP is the massive injector pump that will pull all the way from the tank, the low pressure bit relies on having just enough in stock up front to start. Any part of the LP that is weak enough to allow air in will displace diesel and allow leakback to the tank return.

 

http://i.ebayimg.com/images/g/0aIAAOSwmLlYAS2O/s-l1600.jpg

 

 

[david49west]

 

Have changed the housing and a new filter

the white plastic nut on mine is a water sensor what is tight

When you say the pump has a low pressure part could this side of the pump be faulty

[david49west]

 

All sorted cheers for the advice

 

prob was not only did it have a cracked housing ( leaking out of heater plug connection )

 

also had a crack in the water sensor that screws in bottom of filter

 

change them both but not at the same time

[david49west]

 

thing is just before I read your post I was about to change the pump

only to have found it would have made no difference

so thanks again

 

dave