Problem with (maybe) tandem pump after running out of fuel

freedomlives

Veteran Member
Joined
Aug 8, 2011
Location
Slovakia
TDI
2005 VW Transporter T5, 1999 Skoda Octavia I 1.9TDI
Hi,


We got a 2005 Transporter T5 this summer, 9 seater, with the AXD engine (which i understand is used in the Touareg as well).


Last week, driving home, the low fuel light came on. I figured that as it should come on with 10 liters still in the tank, I wouldn't have a problem to drive to town, which is just 15km / 10 miles away and fill up the next time we were going somewhere. Well, instead, yesterday it died just a mile from our house. I called a neighbor, got a can of diesel fuel I had for my tractor, filled her up and tried starting twice. No luck, realized it would be best to check the internet, and found I should use VCDS to prime the pump, which I tried, no luck, neighbor pulled her home with a tractor, and looking on ELSA software, it said in certain instances 3 minutes of priming was needed. Did that, battery was too low to start, tried again today, no luck.



Code was thrown for the G28 speed sensor, but I read that can come on when starting the engine for a long time. I checked already that fuel comes out of the fuel filter on the line to the tandem pump, so I think all that's left is the tandem pump itself.


Can it get screwed up from being cranked dry a bit? And is the level of screwing up that might occur such that it isn't possible to repair with the kits for repairing tandem pumps? Is there anything else I should still try and/or way to make sure its that pump?
 

1854sailor

Resident Curmudgeon
Joined
Aug 10, 2004
Location
Westerly, RI
TDI
2015 Golf SE SportWagen, 2015 Golf SE Hatch Back.
The PDs are sometimes problematic after loss of fuel or changing a fuel filter. Use a MityVac or similar tool to prime the tandem pump through the return line at the filter.
 

JETaah

Vendor , w/Business number
Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 2005 BEW Beetle, 2005 Jetta Wagon
Pull your glow plugs until you have evidence of fuel mist coming out of the glow plug holes when cranking. It will be faster and easier on your starter and battery. PD's do take a bit to get the fuel system bled...especially if you ran it until it died.
 

freedomlives

Veteran Member
Joined
Aug 8, 2011
Location
Slovakia
TDI
2005 VW Transporter T5, 1999 Skoda Octavia I 1.9TDI
So I tried with my MityVac, and pulled through 400ml of diesel fuel. It was holding a pretty good vacuum, yet there would be alternating periods of diesel coming through and air/vacuum. I wonder if that isn't a sign that its messed up.


The glow plug holes... hmm... https://www.vwt4forum.co.uk/showthread.php?t=153303 I think not such an option in this case.

How long anyway should I be cranking after doing this? I think I did nearly a minute.
 

freedomlives

Veteran Member
Joined
Aug 8, 2011
Location
Slovakia
TDI
2005 VW Transporter T5, 1999 Skoda Octavia I 1.9TDI
I later tried measuring the pressure on the output side of the pump, and it was negligible, so I replaced the pump today, but no luck so far. :-(
 

JETaah

Vendor , w/Business number
Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 2005 BEW Beetle, 2005 Jetta Wagon
I later tried measuring the pressure on the output side of the pump, and it was negligible, so I replaced the pump today, but no luck so far. :-(
That is not where you will find the pressure. You need to test it at the test port not the pump outlet nipple... 6mm allen in the plug.
 

freedomlives

Veteran Member
Joined
Aug 8, 2011
Location
Slovakia
TDI
2005 VW Transporter T5, 1999 Skoda Octavia I 1.9TDI
Maybe after replacing I just need to crank it a lot longer, but battery got low again, so back on the charger. I've got a feeling that I'll have to buy a new battery as well :-/
 

freedomlives

Veteran Member
Joined
Aug 8, 2011
Location
Slovakia
TDI
2005 VW Transporter T5, 1999 Skoda Octavia I 1.9TDI
Oops... that G28 sensor actually probably is the problem. I checked the fuel level in VCDS, and its 25 liters, but I was adding from a 20 liter canister that wasn't even full, so I definitely didn't run out of diesel. Looking at the log from the scan that day, I see the engine was running when the G28 no signal code was thrown.
 
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