Which Is Fuel Pump Relay As Filter Running Dry

[GreenSharanTdi]

Hi all, my green moneypit decided to cut out and not restart BH Monday and i'm a bit confused. Got it recovered then had it towed to the mechanic. No fault codes are coming up, and you can't hear a buzz from the fuel pump when ignition turned on. Glow plug light appears to be working as normal. The fuel filter is running dry and if it's cranked over no fuel is coming through the pipes. If filter is refilled it'll run on tickover for a bit but if you try and drive anywhere it just cuts out and the filter is empty again, mechanic says he can blow thru fuel line no problem. Suspected relay 109 but rang VW and they said my car (2000 Sharan 115 AUY) doesn't have a 109 relay, the gave me part number 4H0906381A as the fuel pump relay which has 645 on it and after googling come up as "additional heater relay". Can anybody shed any light? Does my car have a 109 relay???? I know it could be a knackered fuel pump (it has done 204k) but want to start with the cheapest option first.

 

Thanks

 

[daddyfixit]

you need to get the seats out and lift carpet up to access fuel pump in the tank.  when ignition is on , check the wires to the tank unit with a voltmeter.  if there is a voltage there, then assume in-tank pump has failed.  if no voltage then its time to find a wiring diagram or handbook to see which fuse feed the pump

[GreenSharanTdi]

you need to get the seats out and lift carpet up to access fuel pump in the tank.  when ignition is on , check the wires to the tank unit with a voltmeter.  if there is a voltage there, then assume in-tank pump has failed.  if no voltage then its time to find a wiring diagram or handbook to see which fuse feed the pump

Yes in the process of that now, have eliminated relays 109 and 53 as with replacements fitted still identical symptoms, if you crank it over for ages you can get the filter to fill, it'll run ok on tickover but as soon as you rev for any period of time or try to drive it splutters, cuts out and the filter is near empty again. Suspecting a very weak and tired 204k fuel pump!

[BrianH]

I've not seen it on the galaxy, but have seen on other vehicles that you can end up with crap in the fuel ending up blocking the fuel pickup line, Given your getting something though the pump may be barely working, or may just be gummed up with crap.

 

Its more likely a problem if the cars been stood a long time, or if you've filled up with contaminated fuel at some point.

[brogon]

Have a look at the Tandam vacumm pump on the end of the cam shaft. i have just fitted a new pump and the vacumm was working fine but still had a lack of fuel to the filter.i have 

 

taken out the fuel sender unit and check all the contacts and clean out, you will find an electric motor inside and this is for the Aux/heater. check for electric feed to it if not then check the fuse. the shortage of fuel to the filter will be the Tandam pump you can test it by running a line from the bottom return and the top pipe in to a 5ltr drum  filled with fuel and start the car  as soon as the fuel hits the pump it will start and you will see the return fuel returning back to the 5ltr drum. if that works the tandam pump is ok. then check the fuel lines for a leak or blow them out  and clean out the fuel tank then re test from the car tank,if all lines are clean  you will get fuel to the filter then to the tandam pump and all will be ok......... good look

[chrispb123456]

The intank supplies the tandem pump not the auxiliary/booster heater the latter is completely separate pump mounted in front of the fuel tank adjacent to the inner sill.

If you cannot hear the pump momentarily when you switch on the ignition (squelch noise) then it's not working.

The intank pump keeps the low pressure lines and filter primed continually the tandem mechanical pump supplies the high pressure fuel to injectors and has a separate chamber for supplying vacuum to servo and the small vacuum lines for turbo control (N75) EGR control and manifold flap control.