Engine cuts out at start-up

200Tdi ... when i start her up each morning it will start no problem at all, after a few seconds it then has no response on the throttle and the engine slowly dies. It is definitely fuel starvation but im just wondering what is causing it exactly? To get is started again i have to crank it over for about 5 seconds in total and it eventually fires up cylinder by cylinder. It only used to do it every now and then but recently is been every morning and sometimes during the day after sitting for a while.

Would i be right in thinking that it might have something to do with the lift pump? i did notice that after letting her sit for a while the fuel that feeds the lift pump drains back to the tank, i fitted a jubilee clip onto the pipe to create a tighter fit but it still didn't make any difference?

Any ideas?

With engine off:

1. Crack the bleed screw on top of the fuel filter
2. Cover with a rag and pump the priming handle on the side of the lift pump.
3. If there's air in the fuel filter and the lift pump is capable of priming it, bleed off the air.
4. You should get a good spray/squirt of fuel with each press of the priming handle.

If you're not, then the diaphragm in the pump is probably split or there's an air leak in the pipe on the fuel tank side of the lift pump bad enough to stop the pump from being able to lift fuel.

They're not hard to replace and cost, IIRC, approx £30.

Forgot to add... if air is getting back to the fuel filter it could be the return piping banjos aren't tight enough. Undo slightly and re-tighten... don't be tempted to just nip them up as overtightening can split/snap them.

Cheers Adz,

followed your steps and found the lift pump has got no real pumping capabilities there's about 1cm of the overall travel of the lever that actually pumps, and even that doesn't do much. I couldn't even get any fuel to come out of the top of the filter.

Smithy155 said:

Cheers Adz,

followed your steps and found the lift pump has got no real pumping capabilities there's about 1cm of the overall travel of the lever that actually pumps, and even that doesn't do much. I couldn't even get any fuel to come out of the top of the filter.

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Did any air come out? If not then you might not have opened the bleed screw up enough.

Sometimes the pump gets caught on a cam lobe and won't operate on the lever... might be worth blipping the starter and retrying just to be sure.

I loosened the bleed screw until i could see the little cut-out in the screw, tried pumping for a little while with no result. i then removed the screw completely and tried pumping again for even longer and still no luck.

i'm pretty sure in saying that the lift pump really doesn't feel right. i know when the fuel system is bled up properly that the lift pump looses most of its resistance and the lever becomes easier to move, so with the bleed screw removed the resistance should come back because it's able to pump. but still nothing from it.

it must only be pumping enough to slowly draw fuel into the system to begin with and then leaving the engine to draw all the fuel it needs from then on i guess?

Smithy155 said:

it must only be pumping enough to slowly draw fuel into the system to begin with and then leaving the engine to draw all the fuel it needs from then on i guess?

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If the diaphragm is split it probably won't pump at all. The engine won't draw fuel as such, but the injection pump will. I'm not sure the IP has much suck though, hence the need for the lift pump.