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

I have removed the mod for the time being, and checked all the wiring to the quantity adjuster.

As earlier, it runs/drives fine, it`s just taking ages to start.

 

Try cracking an injector as if you were bleeding it, see if any difference to the start then.

Did you change the filter over to non-T type? If not put a bit of clear hose in the return line. Presuming no bubbles in the existing clear line?

 

taking ages to start, prime starting point is restriction on fuel lines/filter/pick up pipe
more so if it struggles cranking after left overnight/couple hours

seen it loads of times, clear line tubing does help

 

Is there a filter inside the tank on these? As I say, I ran mine ridiculously low the other week, only just got to the fuel station.

Mine will struggle to crank in <20 mins after switch off.

 

Should be a little gauze type, personally don't see the point in them as long as you keep up with main filter changes.
Chris, if no fault codes, look at the basics: - cranking speed (try it with a booster attached), air in fuel line, compression

 

If there is air in the fuel line - seems plausible - will it not disappear of its own accord, or do I need to work some magic on it?

Must say, having changed a fuel filter and made my car worse, it really has reached a new DIY mechanic low.

 

All diesels without lift pumps are very hard to start after filter changes.

Air will disappear if its purely from changing the filter, but if there is a split hose/bad seal then you will have constant starting problems.

 

When I changed my filter (to Rover 600 non-tee type, as linked in post 1) it took a couple of goes to start, and coughed for a bit but then ran perfectly, so I wouldn`t expect any air that`s entered the system (in Chris` case) to be due to the filter change.

Chris` hypothesis regarding perhaps picking up sludge from an extremely empty tank is beginning to sound...er...sound (). I also ran mine very low a couple of days prior...

I think it might be worth throwing a new filter on (in my case) and see what happens.

 

Haven`t got round to trying a new filter yet, but had at a look at the measuring blocks on VAGCOM, and though it gave loads of interesting results, I have no idea how to interpret the figures. By that I mean I know what is being measured and why, but not sure on whether the numbers are correct or not, so any help deciphering it would be great. (Specific questions/observations in bold red)

Group 001 - Injected Quantity.

Revs - 903rpm.
Inj. Quantity (IQ) - 4.4mg/str.
Modulating piston displacement - 1.420 V.
Coolant Temp. - 72deg.

Group 003 - EGR

Mass Air Flow (specified) - 255mg/str. }
Mass Air Flow (actual) - 508mg/str. } [To my untrained eye this seems like a massive difference...]
EGR Duty cycle - 49.8%. [EGR valve is blanked off, and vac line removed if it makes a difference]


Group 004 - Start of injection

Specified start of inj. - 0.9deg BTDC.
Actual start of inj. - 0.7-0.8deg BTDC.
Cold start valve - 33.5%.

Group 005 - Start conditions

Start IQ - 29mg/str.
Actual start of inj. - 0.9-1.1deg BTDC.
Coolant Temp. - 77.4deg.

Group 007 - Temperatures

Fuel temp. - 52deg.
Inlet air temp. - 28.8deg.
Coolant temp. - 77.4deg.

Group 008 - Injected quantities (undocumented)

IQ? - 0.0mg/str.
IQ? - 28.2mg/str.
IQ? - 28.4mg/str.

Group 009 - IQ Limitations

IQ CC Active - 0.0mg/str. }
Inj. Limit a/t shift - 51mg/str. } [No idea what these are.]

Group 010 - Air System

Mass Air Flow - 512.0mg/str.
Barometric Pressure - 1009.8mbar.
Manifold Air Pressure - 999.6mbar.
Throttle position - 0%

Group 011 - MAP

Specified MAP - 948.6mbar.
Actual MAP - 999.6mbar.
Duty cycle boost valve - 91.6%.

Group 013 - Idle speed smooth running adjustments

Cyl. 1 - -0.05mg/str.
Cyl. 2 - -0.33mg/str.
Cyl. 3 - +0.05mg/str.
Cyl. 4 - [This block was blank...]

Group 015 - Fuel Consumption

IQ (actual) - 4.0mg/str.
Fuel consumption - 0.39l/hr

Group 016 - Auxiliary Heater

Generator loading - 99.6%.
Auxliary heater - 00000001. }
Activation - 00. } [Not sure what these two are.]
Voltage supply - 13.8V.

Group 021 - [No title]

Mass Air/rev - 255mg/str. }
Mass Air/rev - 505mg/str. } [Assuming these two are `specified` and `actual`. Again, seems like a large difference.]
Duty Cycle - 49.8%.
Bin bits - 010 000. [Need a steer here.]




Any help/guidance much appreciated as always.

 

Group 001 - Injected Quantity.

Revs - 903rpm.
Inj. Quantity (IQ) - 4.4mg/str.
Modulating piston displacement - 1.420 V.
Coolant Temp. - 72deg.

All Fairly Normal

Group 003 - EGR

Mass Air Flow (specified) - 255mg/str. }
Mass Air Flow (actual) - 508mg/str. } [To my untrained eye this seems like a massive difference...]
EGR Duty cycle - 49.8%. [EGR valve is blanked off, and vac line removed if it makes a difference]



EGR being blanked is the cause for your big difference in actual and spec, nothing to worry about here.

Group 004 - Start of injection

Specified start of inj. - 0.9deg BTDC.
Actual start of inj. - 0.7-0.8deg BTDC.
Cold start valve - 33.5%.

Seems about right.

Group 005 - Start conditions

Start IQ - 29mg/str.
Actual start of inj. - 0.9-1.1deg BTDC.
Coolant Temp. - 77.4deg.

Try looking at the coolant temp when the engine is cold, does it match what a thermometer does?

Group 007 - Temperatures

Fuel temp. - 52deg.
Inlet air temp. - 28.8deg.
Coolant temp. - 77.4deg.

Group 008 - Injected quantities (undocumented)

IQ? - 0.0mg/str.
IQ? - 28.2mg/str.
IQ? - 28.4mg/str.

These are fine, first one is drivers wish IQ eg you have 0 throttle so no injected fuel. The other two are values for the smoke and torque limiters. Both of these are normal.

Group 009 - IQ Limitations

IQ CC Active - 0.0mg/str. }
Inj. Limit a/t shift - 51mg/str. } [No idea what these are.]

I believe they are to do with if you have cruise control and or automatic transmission

Group 010 - Air System

Mass Air Flow - 512.0mg/str.
Barometric Pressure - 1009.8mbar.
Manifold Air Pressure - 999.6mbar.
Throttle position - 0%

Group 011 - MAP

Specified MAP - 948.6mbar.
Actual MAP - 999.6mbar.
Duty cycle boost valve - 91.6%.

Group 013 - Idle speed smooth running adjustments

Cyl. 1 - -0.05mg/str.
Cyl. 2 - -0.33mg/str.
Cyl. 3 - +0.05mg/str.
Cyl. 4 - [This block was blank...]

That block is always blank and those adjustments are fairly good.

Group 015 - Fuel Consumption

IQ (actual) - 4.0mg/str.
Fuel consumption - 0.39l/hr

Group 016 - Auxiliary Heater

Generator loading - 99.6%.
Auxliary heater - 00000001. }
Activation - 00. } [Not sure what these two are.]
Voltage supply - 13.8V.

Group 021 - [No title]

Mass Air/rev - 255mg/str. }
Mass Air/rev - 505mg/str. } [Assuming these two are `specified` and `actual`. Again, seems like a large difference.]
Duty Cycle - 49.8%.
Bin bits - 010 000. [Need a steer here.]




Any help/guidance much appreciated as always.


Nothing really seems very wrong. Looking at temp sensors when the engine is completely cold can give some hints though.

 

Cheers Mike.

The coolant temp. would be about right, since I had driven to a mates house and it had only been off for 15 minutes or so prior to plugging VAGCOM in.

So, back to square one then...

EDIT; Just realised you meant 'Look at the coolant temp. when the engine is cold...

 

How is the idle on yours Stu? Mine wobbles every 15 seconds or so, and sat at the lights too long, you'd swear it was "fouling the plugs" []

Slow pick up on clutch-up & benefits from a "throat clear" before it moves normally. Cannot fathom it.

 

Shamelessly stolen logging guide. http://malonetuning.com/guides/vagcom/vagcom_logging_guide.pdf

If you can log all of the ones suggested for 1996-2003 tdi's in the way it describes it might unearth something.

 

Idles spot on. Can be a bit slow on pick-up some days, but I just put that down to probably coking up a bit due to the short journeys I tend to do. Good blast up the motorway usually sorts that out.

 

That`s a handy guide, thanks.

Not too sure it would help in my case though since it runs perfectly well (or at least no different than it did).

 

Sometimes it can show that things are out. Is your friends vag-com a full version if so might be worth checking the timing with that too.

 

update?

 

Log looks normal, have you checked fuel filter or the intank unit for how clean it is or any other isues

the long start time and as you desribe as poor around time, me thinks air in system/lack of fuel

 

Wrote a big post about how nothing much has changed, but I`ll be giving it a good coat of looking at tomorrow, before the forum decided it didn`t want to load the page...

 

I've found the culprit on mine. Nipped down the scrappy and got some OEM clear feed hoses from a Mk3 (also found an N-reg Passat with them - must have been a very late spec upgrade as mine had black lines). Anyway, really glad I did this as it showed massive amounts of air in the fuel feed line.

I'd looked in the tank previously (not really filtered in there, just plastic mesh and hardly anything caught), so the puzzle of WTF was going on could only be the tank exit rubber lines, plastic lines under car or engine bay. Spotted this, covered it with fingers, and the bubbles obviously reduced:





It had been rubbed away by the corrugated platic inlet air trunking from MAF to hard turbo plastic inlet pipe.

Amazingly it wasn't leaking diesel though, and there is a rubber inner section to that pipe with the fabric in the wall...

Starting is now back to normal, flick of the key.