Fault code 01268 - Quantity Adjuster (N146) **New developments**

Super!

The trouble in finding these things is, a rubber hose like that can be porous enough to let a ruinous amount of air in, but no fuel out, so you can`t pinpoint it easily!

Hoping to find something similar under mine...

 

Bit of a (downward) development;

Had a good root around the fuel system on Friday, and found one of the unions from the injector pump was loose. `Hoorah!` I thought, but it made no difference...

Still not starting well on Saturday, and was now struggling to make much power above 2000rpm, wasn`t pulling well from a standstill, and had a few `hiccups` under partial throttle.

I pencilled today in as a day for intense investigation, and lo and behold it decided to throw it`s hand in altogether yesterday morning just as I was getting ready to attend the VWNW show...

Scanned for codes and it came up with the MAF (G40), and fuel shut-off valve (N109).

After a Google around for N109 faults, it appeared a curious, but pretty common fault was the cause; apparently there`s a sealing o-ring in the shut-off valve that can un-seat and cause power-loss/non-start issues, so that was the port of call today...

This is the offending article here (with the single wire).



Remove the single ring connector (8mm nut). Also un-plug the connector nearby, and unbolt it`s mounting bracket for ease of access later.



Undo the injector unions for No.3, and No.4 injectors. Slacken the union for No.4 injector at the pump, and move the pipe back out of the way. Undo the No.3 pump-end union, and remove the pipe altogether.



24mm spanner needed to remove the solenoid, thusly.



You`ll now see the core/valve part of the solenoid. Retrieve the spring (don`t loose it!)





Here you can see the o-ring sitting around the base of the valve part (where it shouldn`t be)...



...and removed.



Remove the o-ring, and re-seat it back where it should be on the solenoid body.





Re-assemble and all should be well...

Because I had cranked the engine for ages previously, the injectors were `dry`, so needed bleeding before the engine would start; as simple as cracking off the four injector unions, then cranking until fuel squirts out, then re-tighten the unions and start as normal.

Car now runs with no hesitation, and much better than it has for a while. Obviously this has been a slow deterioration of power so hadn`t really noticed it, but now it`s very obvious how bad it was!

Still doesn`t start as `on the key` as it did, but hopefully a good thrash tomorrow will make sure there`s no more air in it...

The cleared MAF fault hasn`t come back (it had a good clean a couple of weeks ago), but would a dicky MAF cause starting issues?

 

I had that problem on my first tdi. I fixed that and fitted a tuning box, I swear I had over double the bhp I had 10 minutes before!

How long ago since its last cambelt? You could try advancing the pump as far as it goes within the 3 mountings.

 

Such a simple, easy fix, but no idea how I would have found it alone...God bless the Internet!

No idea if I`m honest. I`ve had it nearly two years now, and though I know it was regularly serviced by the PO, it`s probably fair to say the cambelt is overdue.

I`ve been reading that commonly the pump can jump a tooth or two on the belt, so I think I`ll get that done, and see if it helps any.

 

I had a similar starting issue as yours on my old L200 (very similar pump), ran fine, idled fine, but took 2-3 cranks to start.
Fully advanced the pump in its elongated mounts and the starts became instant.

All you need to do is slacken the 3 small bolts, twist the whole pump anticlockwise - i.e. top of the pump toward the rocker cover, tighten back up (It sounds backwards, but you are effectively advancing the sprocket by moving the rest of the pump back).
If you can get to the bolts ok, its literally a 2 minute job

 

Well, it was a real b*tch to start this morning so I`ll give advancing the pump a go, before I end up killing the (fairly new) starter motor.

Seems like a bit of a `bodge` to hide another problem, but suits me fine if it gets it starting better!

 

With this from TDI Club FAQs...

...and looking back at my VAG-COM results...

...would suggest (I think!) that it would indeed benefit from being advanced?

If that`s right, the question would be; Why would it go from fine to needing advanced literally overnight? (started within a couple revs when leaving a mate`s. Next morning, 10-15secs of cranking needed...)

 

I found retarding mine too far and it would simply not start.

The pump needs to be twisted with the top towards the steering wheel to advance. The movement it has is not huge. Best to pen-mark the orig position. Four 13mm bolts, two through the fuel pump pulley and two visible on the pump body side, one at the far end of the pump.

Position can be checked in Vagcom first to comfirm the actual situ, though is a real fiddle to get to the graph in the menus:

http://forums.tdiclub.com/showthread.php?t=269567

http://www.tdiclub.com/TDIFAQ/TDiFAQ-7.html#k

 

Cheers, Chris.

First link isn`t working, but I have read the FAQ one already (been all over TDI Club for ideas!)

From there I`ve got a couple of other avenues to check before I go advancing the pump, but hopefully the end is in sight!

Either that or I`m burning the f*cker...!

 

10-15 seconds of cranking? I do not read threads properly! I thought it had gradually got worse and took 3-4 turns to start! I can't see advancing the pump helping you to be honest. In the meantime to save the starter use a small amount of carb cleaner in the airbox.

Just had to replace the pump on my non-tdi due to it pulling air in through the 'front' seal if you like, i.e behind the sprocket, same symptoms as yours.

 

Now fixed - it shows the graphs.

Due credit to Crispy who pointed this shizzle out on Vagcom.

 

Aye...seen that one too!

 

Only on the very first start of the daydoes it take up to 10 or so seconds to fire. This morning it wouldn`t fire at all again, so I cracked an injector pipe. Fuel was there pretty much straight away, but it still took a good 3-4 secs before it fired.

Checked voltage to shut-off valve again - All good (and it shuts it down fine if you earth it)

Been reading up about check valves that some cars have in the delivery line right by the tank. Seemed plausible, since the symptoms were similar (ie, fuel `primed` in the delivery line leaking back to tank over a few hours leading to slow start), but I don`t appear to have any check valves...

Replacing the pump is the last thing I want to do really, because; 1) It`ll be right royal PITA, and 2) I can`t justify the cost given the car cost less than pumps seem to at the moment (unless someone wants to part with a known good one for ~50... )

 

You could put a check valve by the filter if you wanted to try that (8mm), but that will just prove its air in the system. Does it make a difference if the car is parked up or downhill?
Have you changed the little sections of leak off pipe?

 

There`s no hills around here to park it on, so haven`t tried that. Think I`ll stick the back on axle stands overnight tomorrow, and see how that checks out.

Leak off pipes from the injectors? Still on the originals, but would they let air back into the system? I`ve got some suitable replacement stuff that I was saving for the injector swap, but I may as well swap it now.

 

As far as I know, they can cause issues. Maybe its because the leak off pipes (and air) go back to that banjo on the pump before returning to the tank, not really sure to be honest. Worth changing if you already have them.

 

Yeah, good point. Worth a go, as you say.

 

HI all. Just joined the forum , and have got the very same problem on my 1996 Passat 110bhp 1.9tdi.
Done 326k miles now, 100k miles on homemade biodiesel.
Got the same fault code, same problems starting, but runs fine.
Not glowplugs, fuel filter, or air leak.
Think its down to quantity adjuster/ fuel regulator valve issue - thingy on top of fuel pump - sealed unit I think.
Timing related? timing belt has done 71k miles now, so could be timing slippage or jumped a cog, but it runs fine down the motorway!
Help please.