UK-POLOS.NET - THE VW Polo Forum

Hi,
I have a polo 1.4 / 2010 which turns over but won’t start.
I have changed the spark plugs, and they are giving a good spark. I then checked the fusses for the fuel pump, which were OK. I tried to release the pressure on the fuel rail but their was no pressure, so I went to the fuel pump under the rear seat and disconnected the power supply plug. With the ignition on I checked the pins for power, but got nothing.
Thinking it must be the relay I removed it, and plugged it back in. The car then started and idled on two occasions before dying, and hasn’t started since.

When should I get power at the plug connector on the fuel pump.

Any help please.

Thanks Dave.

might be worth checking fuse 49 below the steering wheel
this supplies power to both (2) fuel pump relays.

did you notice any other things not working, apart from the engine not starting?

Everything else is working OK, but I would expect some power at the fuel pump connector to the petrol tank, when the ignition is on. I will try fuse 49, when it stops raining. Thanks.

Remember that if that fuel pump was happy to run any time, if you had a crash you would be in trouble, so some safe guards have been put into place to avoid that happening. I think that the fuel pump will only run for X seconds if there are no sparks being detected, maybe that does not answer any part of your question, but maybe it does indicate, if you did not know, how or why or when the pump can be expected to run.

So I could be looking in the wrong place.
Thanks for that.

Hi,
Definitely NO power, at the plug connector at the fuel pump.
Having checked everything else, I went and bought a new Fuel pump relay (449), plugged it in and the engine started perfectly first time. After a few engine starts the engine management light went out as well.

Thanks for your info.

Excellent!

An update.

The relay was not the problem. So I looked closer at the power connector that goes on top of the fuel pump under the back seat. I noticed that if I moved the blue/white wire the engine would start, and I could hear the pump working. However if I moved the wire to one side the pump would stop, and the engine would cut out.

Is their anyway of getting to the connector to slightly tighten it up.

Thanks
Dave.

Sounds like either a wire that is not properly seated in the connector or a broken wire?
It's important to find out why it will not work. And repair it properly. Judging from the information you provide, it's hard to say.
It's essential for the fuel system to be in perfect condition at all times, for your safety and the safety of others.