I'm an IDI guy so I haven't really versed myself on these new fangled devil machines yet..
The car in question is a 2000 Beetle TDI sporting about 168K belonging to a buddy of mine.. He had it to a pretty reputable TDI guy with no luck so far.. Of course it never gave trouble when he was working with it.. Here's the poop..
Runs excellent when it runs.. But every few weeks is dies.. No warning, just looses power like it's outta fuel and dies.. Already addressed relay 109...
The first time it did this it was 50 degree F weather. I went and towed it to my place.. Got a P1248 out of it.. Pulled the return off the pump and cranked, no fuel.. Disconnected the inlet to the pump and put air pressure to the tank, slow trickle of fuel.. Pulled the line off before the filter, air to the tank, slow trickle of fuel.. Pulled the sender out of the tank and the screen had a bunch of crap in it.. Cleaned that out, inspected the pickup, blew out the line, replaced the filter and she ran for about a month.. I *think* it had around a half tank in it at this time..
The second time (4 weeks later) it did this is was -10 degrees F and 3 in the morn
.. Had the P1248 again. Went and got it, put in in the garage (heated) and dealt with it the next day.. Pulled the return line and cranked no fuel, pulled the inlet to the pump and put air to it, got fuel gushing out in a few seconds.. We chalked this one up the the fuel gelling.. And he started running I think the Power Serve stuff.. It had about a quarter tank of fuel..
Third time, (3? weeks later) also around 0 degrees F, about a half tank of fuel,I towed it to the TDI guy. He replaced the filter, primed it and it ran fine.. Had the P1248 again. He drove it for 2 weeks with no issue.. And gave it back..
Here we are again, a couple weeks later, all the same symptoms, bled the fuel system, it runs great. I can't see anything floating about in the tank, I'm wondering if there could be random issue with the float on the bottom of the in tank unit, the one for the "anti slosh" not the gauge. Possibly after a bumpy trailer ride it rattles back up and all works?? I'm pretty sure the fuel gauge is reasonably accurate, I pulled the sender out and had a look down in there a bit ago..