Fuel pump noisy

[brucegtx]

I'm trying to solve my fuel issue on my gtx and now down to the fuel pump. How can I tell if my fuel pump is not working properly. It's priming prior to starting but is constantly buzzing when running. Is this normal?
My Rocco fires up first time for about 30 seconds then chugs out, I then restart it and it then lasts about 5 seconds. If I leave it for 10 mins or so and start it again it will last for 30 seconds and so on.
Tank cleaned, filler neck ok, plunger ok, aux air valve changed, lift pump changed, plugs changed, dist cap ok, coil ok fuel filter changed but not since tank cleaned? Pump?
Really getting pissed off now as she looks stunning but won't bloody run!!!!!

[DannyH]

Have you checked the fuel pump relay?

[ianaudia4]

It could be the fuel pump but it isn't a certain as both of my Sciroccos are injection, one has a louder fuel pump than the other and they have both been like that for 5 years!
If you have a spare pump try it, even to illiminate it! You haven't mentioned fuel pump relay, have you tried another?

I asked you before about the metering head, you said it works fine but have you tried another?

There is an accumulator as well (near the main fuel pump), this could be faulty as well.

[brucegtx]

Hi Ian, had a new relay quite early on so that's ok. Took the acumulator off and cleaned it all up with the pump and swirl pot when first sorting out and looks ok, but it's what's inside I suppose. I've been trying the smaller things first but looks like I need to get a new pump first, or borrow one to see if it's that. It's Defo fuel starvation though.
You can get a pump overseas for about £35 new or gsf £75, am I best to steer clear of the less expensive ones or not?

[ianaudia4]

I wouldn't go down the route of a cheap pump if you intend to keep the car.
The originals were either Pierburg or Bosch.

Where are you based as I have a spare you could try if you are local to London or Essex?

[mark1gls]

Have you checked the lift pump in side the fuel tank? If it fails it makes the main pump work harder so it makes more noise.
Get relay No 17/18 from your fuse box and put it where the fuel pump relay is, this will make the fuel pumps run as soon as you turn on the ignition, in my car I've No 18 and it's the relay below the fuel pump relay and you need to turn the relay so it's upside down to fit it.
Take the back seat base out and undo the round black cover to get access to the top of the fuel tank, unplug the electrical connection going to the sender at the top of the fuel tank, turn the ignition on so the main pump runs then plug in the electrical connector back onto the sender on top of the fuel tank to see if you can hear the lift pump run.
If not running remove the lift pump check it by connecting it directly to the battery, replacements are £25 ish

Lift pump
http://www.ebay.co.uk/itm/VW-Golf-1-8-G ... 2a14d2bd53

[mark1gls]

Just read your other post and realized you have already changed the lift pump, they are noisy fuel pumps but at least you can hear they are working when driving!
Relay tick handy to know if your relay stops working when driving you can also bridge the 2 larger connections with a bit of wire to get it pumps running but they will run all the time even with the ignition off, I got home this way once when my fuel pump relay stopped working on the way home from work.

[bensspares]

Does the fuel pump get louder the nearer to it cutting out it becomes ?

[duggers]

Your symptoms are exactly those of a faulty lift pump. Have you checked there is power to the lift pump and that fuel is being delivered to the under body pump. It is possible to have faulty new components so worth checking even though it seems unlikely.

[brucegtx]

Think I've solved the problem guys! Although I've replaced fuel pipes, new fuel pump, lift pum, aux air valve, cleaned tank out, new plunger and checked metering head i think the problem was a knackered fuel filler cap! Aaaggghhh! It was in the garage and after they had changed fuel pump and pipes it was still cutting out. As they were checking the pipes they noticed the rubber pipe between the filler neck and tank was sucking in due to a vacuum. As they released the petrol cap this solved the problem and ran like a dream after re setting the mixture to about 1.75.
Passed mot and now about to take it for a good run to make sure.
So for all you guys with a similar problem, it's worth checking the bloody petrol cap!

Do any vw petrol cap fit ie mk1 or 2 golf, jetty, polo ect?