Poor Starting (only When Cold)

[AndyR]

Hi, Please help?

 

Vehicle is a 2001 MK11 1.9tdi Ghia Manual

 

Problem

 

When starting from cold the engine will not fire. It turns over and then gradually comes into life. similar to what you would expect with faulty glow plugs (kind of fires on 1 cylinder then 2 then 3 etc). Hence all 4 have been replaced but still the same.

 

Engine driven fuel pump also replaced with new but still the same.

 

No fault codes/engine lights appearing and I couldn't see anything obvious on VAG COM.

 

 

Possible Cause

 

However, believing it maybe a fuel issue I have just fitted clear fuel lines to and from the engine driven fuel pump. When running perfectly as expected the lines appear to be full of fuel.

 

Once left the return from the engine driven fuel pump to the fuel filter begins to get air in it. The supply (from the fuel filter to the fuel pump always appears ok and full of fuel)

 

When I try and start the vehicle initally nothing comes out of the pump return to the filter but then as more and more fuel comes out the engine kicks into life. Its as if the fuel is refilling the injector rail or something.

 

Fix

 

Can anybody suggest why I maybe getting air (only) in the return from the fuel pump to the fuel filter.

 

Has anybody come across this before?

 

Seriously need your help guys.

 

With thanks in advance.

 

Andy

[seatkid]

check the electric lift pump in the fuel tank is working.

[AndyR]

Electric lift pump in tank is working and fuel under pressure comes out of the fuel filter. The characteristic whoosh when you turn the ignition on can be heard.

 

Any other thoughts/comments welcome :blink: