Mk7 starting issue

[Dav06gab]

Hi my 11 plate 2.4 transit having starting problems. Starts fine when warm however when left overnight it won’t start. I have checked battery connection, fuses, immobiliser light goes off and starter motor is ok. Just had brand new fuel filter head assembly put in not that long ago. Managed to actually get it started yesterday by taking fuel filter out , filling it up with diesel and purging injector lines. I don’t think it’s sender unit as it’s got 3/4 of the tank and as a precaution I’ve put 5 litres in prior to taking fuel filter out and it wouldn’t start.
It seems like It’s got air in fuel system and I am wondering what things shall I look at next.
Any advise is much appreciated.

[v8dave]

Injector lines are self bleeding.

Seems like you have an air leak.

Could be defective new filter head, but more likely a damaged pipe or connector when it was fitted.

[Dav06gab]

Thanks for your reply. Oh will never bleed them again. I’ve noticed today drain sensor pipe is missing, could this caused such an issue ?

Fuel hoses are like new and couldn’t see anything obvious.

[knobby1]

Thanks for your reply. Oh will never bleed them again. I’ve noticed today drain sensor pipe is missing, could this caused such an issue ?

Fuel hoses are like new and couldn’t see anything obvious.

Filter drain normally doesn't have anything connected...and won't be the cause of your issue. The filter housing that the filter lives on can crack can let air in whilst sitting, this lets the fuel drain back to the tank and causes "hard to start" syndrome. Similar thing can happen with the injector leak-back hoses, if the "O" rings aren't happy, they''l let air in.

Also check the filter housing "quick disconnect" fittings, the "O" rings in them can also fail...not common but possible.

Lord Knobrot

[Dav06gab]

Thanks for sharing the info. I will strip the filter assembly and have a close look at the injector hoses tomorrow. My other 12 plate 2.2 mk7 has a different filter housing which I never had problems with after changing the filter, just wondering if it’s a straight swap onto my11 2.4 ?

[knobby1]

Thanks for sharing the info. I will strip the filter assembly and have a close look at the injector hoses tomorrow. My other 12 plate 2.2 mk7 has a different filter housing which I never had problems with after changing the filter, just wondering if it’s a straight swap onto my11 2.4 ?

Your 12 plate will be a Euro-5....the 2.4 will be Euro-4, different filter setup for each. Also different fuel injection system, Euro-4 will be Denso, Euro-5 will be Siemens.

Lord Knobrot

[Dav06gab]

Thanks for sharing the info. I will strip the filter assembly and have a close look at the injector hoses tomorrow. My other 12 plate 2.2 mk7 has a different filter housing which I never had problems with after changing the filter, just wondering if it’s a straight swap onto my11 2.4 ?

Your 12 plate will be a Euro-5....the 2.4 will be Euro-4, different filter setup for each. Also different fuel injection system, Euro-4 will be Denso, Euro-5 will be Siemens.

Lord Knobrot

Oh ok that explains a lot. I’ll try to locate the leak and go from there. Cheers

[Dav06gab]

Surprisingly van started up ok. I hope that refitting the filter solved the problem.
Have ordered fuel syringe so will be able to bleed the system properly and see if the problem is still there

[Dav06gab]

After closer inspection one of the lines has damaged o-ring inside the connector. I’ve ordered new lines and wondering what is the most efficient way to bleed it out ? Mine don’t have a bleeding valve or nipple.

[Dav06gab]

Here is the picture

[knobby1]

Mk7's are self bleeding, just make sure the filter is full before starting.

Lord Knobrot and

[bambi mk 1]

Thanks for your reply. Oh will never bleed them again. I’ve noticed today drain sensor pipe is missing, could this caused such an issue ?

Fuel hoses are like new and couldn’t see anything obvious.

Someone has fitted a one way valve to the pipe I would change the pipe as the valve will act like a main jet.

[Dav06gab]

Thanks. I’ve managed to replace the fuel lines purge the system, it starts okay now however when I go over 5mph in either first or reverse ESP light comes on and cannot be switched off. Any ides what could be causing this ?

[Dav06gab]

Forgot to add after scanning there is no DTC fault at all.

[knobby1]

Forgot to add after scanning there is no DTC fault at all.

If the ESP light is coming on, there "Will" be codes stored. What scanner are you using..? Have you replaced any tyres or had the brakes worked on lately..?

Lord Knobrot