AIR in the fuel line!!! Dci problem please help

[Sparky1983]

Hey had the mechanic over tonite about my recent starting problem and we identified MASSES of air in the fuel line visible between the high pressure pump & the fuel filter & line attached to other end of the primer (where does that go?)

Does anyone hav any idea how the air could have got in there? we tested it by pumping the primer which seemed to generage huge quantities of bubbles, the fuel flow actually running dry in places where some of it was being sucked up and some just flowing back into the tank again.

Are the fuel filters prone to air leaks? what about the fuel line connectors can they loose their seal? If i were to try and replace the fuel lines can you just buy certains bits of the line or do you have to buy the whole shabang going right back to the tank?

Any light please

[SkidMarx]

They always show air in the fuel lines. You could look at a good one and it would still have air in it. Have you had clip on it? More likely that there is a fault either with the fuel pressure sensor ( on the fuel rail) or the pressure regulator on the pump.

Clips a handy tool for these faults. One other fairly common starting problem is faulty injectors. If an injector sticks in the 'open' position then it takes longer for the pump to build up enough pressure for the fuel rail ( 180 bar for starting i think).

[phoenix1]

some air is normall lots isnt ,check fuel line is seated properly, fuel filter ??? been replaced recently ie in the last week,filter life guage in filter head in red ??

you get some 'air' in the fuel due to the engine vibration you ought to see a new transit you thought it run on air and diesel was the contaminant
mick

[SkidMarx]

Yea renault fault finding tells you to check for air in the fuel, but its a grey area as to how much is excessive. Back to basics really. clip check, injector leak off test, check fuel pressure when cranking ( 180 bar iirc ) check compressions etc

[Sparky1983]

We used 6 grand diagnostic equipment which showed the common rail was reading too low a pressure - not suprising when we saw how much air in there! he was sayin that with these cars the fuel was being 'sucked' in by the high pressure pump but that that sucking action wouldn't be as effective if there was a lot of air in there.

The air was in the lines between the high pressure delphi pump & the priming blub (obviously with the fuel filter in the middle).

Gonna change fuel filter 1st off to see if that makes a difference. The car now starts btw which is good but i'm stil not usin it until we know wot to fix.

[Scrooge]

i had this exact same problem mate what it was the was the fuel pump under the rear seats take it out and theres like a little tea strainer clean it out as its usually full of s**t. when you put it all back on there will be no air yay

[Sparky1983]

i had this exact same problem mate what it was the was the fuel pump under the rear seats take it out and theres like a little tea strainer clean it out as its usually full of s**t. when you put it all back on there will be no air yay

Thanx buddy i'l give that a go! do hope its something simple like that otherwise tracing the leaks gonna be a costly nightmare

How easy is the fuel pump to get at / remove?
Could i do it myself with spanner and cerebrum?? i just take the back seats out rite??

[Sparky1983]

How do you remove it?? Ive revealed the pump and disconnected the leads but where to now?? help