Upsolute + N146 intermittant

[jameshughes1974]

Hi
My car is a 1998 A4 TDi with the AFN engine. Since having the car chipped (maybe coincidence) by upsolute last year, slight throttle in fifth gear at 40-50 mph gives a slight judder. more recently my glowplug light is flashing and the car judders more.
The car has had a new fuel filter and has been throught more than one tank of fuel on the problem. No biofuel has been used in this car.
Timing is spot on.
Vagcom gives a N146 intermittant error which wont clear.
This refers to the quantity adjuster in the vp37 fuel pump. Using audi's diagnostics I have verified the resistances across the adjuster are correct and the signal coming from the ecu is correct and the 8 pin connecter to ecu connector is connected and not shorted to anything.

Does anybody have the answer to this. Some forums would suggest that it is the "Chip" that is causing this.
Does anybody have the circuit diagram for the ecu in this car so I can verify the return signal from the quantity adjuster is getting to where it needs to go?
I have emailed Upsolute and await a reply but thought I would ask those who know as well!
The car is standerd other than a drop in K+N panel filter.
Thank you

 

[inigoj]

What bhp are you running?

Are you using bigger nozzles?

I would suspect that your quantity adjuster has reached its upper limit, and can not supply the requested fuel at high road speeds, it may be throwing a similar DTC:

01268 - Quantity Adjuster (N146)
35-10 - - - Intermittent (cant supply requested fuel/physical limit)

Unless you have pushed your power to the max, or your fuel mapping at higher speeds is dodgy/overfueling (would explain the judder), you should not be getting this problem.

Was it an generic 'offset' map, as that may explain the top end fueling problem.

If your pump timing is 'spot on', where is it set?

Setting the static timing right at the top end of the injection window would help the problem (advanced).

Or changing to a higher profile 11mm pump rotor (automatic pump etc).

Could also be a physical quantity adjuster or wiring problem.

 

[jameshughes1974]

What bhp are you running?
143 BHP

Are you using bigger nozzles?
No – Nozzles are as fitted at factory.

I would suspect that your quantity adjuster has reached its upper limit, and can not supply the requested fuel at high road speeds, it may be throwing a similar DTC:

It looks as below but it turns the MIL on after 30 seconds of the ignition on but engine not running- this would suggest some thing else than “unable to deliver at high speed” as the engine isn’t even running

01268 - Quantity Adjuster (N146)
35-10 - - - Intermittent (cant supply requested fuel/physical limit)

Unless you have pushed your power to the max, or your fuel mapping at higher speeds is dodgy/overfueling (would explain the judder), you should not be getting this problem.

Was it an generic 'offset' map, as that may explain the top end fuelling problem.

Generic meaning off the shelf – yes – no rolling roads/tweaking

If your pump timing is 'spot on', where is it set?
Off hand I can’t quote the figure but using the TDI timing graph in vagcom for the AFN engine it was bang on the middle line. However since I posted I have changed the cam belt and the timing is slightly more advanced but the error remains

Setting the static timing right at the top end of the injection window would help the problem (advanced).

Or changing to a higher profile 11mm pump rotor (automatic pump etc).

Could also be a physical quantity adjuster or wiring problem?

I am not keen on going down a bigger pump route as it should be able to handle the generic “upsolute”.
The car doesn’t seem to have a problem delivering power even with this error.

I have read about people doing the “Hammer Mod” but this seems to be used when the fuel quantity is out of spec (3-9mg) mine is actually in spec at 3.9mg(ish)

 

[inigoj]

The fault code is not a problem, it is just the quantity adjuster complaining that it has reached its upper limit.

The fueling at higher speeds may be a bit aggressive, which may cause the juddering.

 

[jameshughes1974]

hmm- could do with sorting it thought as I actualy want to sell the car- Hands up who would buy a car with a MIL flashing and not be levering a big discount?
To anybody who knows the inside of these fuel pumps, would a 11mm rotor cure this?
Is this error because the quantity adjuster is hitting the end stop on the standard pump .
Thanks for the info so far.

 

[inigoj]

The quantity adjuster fault code i posted was from running a 'tuning box' set too high.

This was a software/engine management problem.

If your fault code was identical, I would think that you need to get the tuner to look at it again.

There are different codes for physical upper/lower limit and control difference etc.

What was the exact fault code?

When does the glowplug light start flashing?

What is your current IQ value?

Exactly what hardware has recently been changed (new maf etc?).

It sounds daft, but maybe the car was running ok with the old filter, and the new filter has improved fuel flow?

 

[jameshughes1974]

Thanks for the continued help, i will vagcom the car tomorrow to get specific answers(but iq around 3.8/4mg).
The K+N has been in for 2.5 years with no problem.
I remembered that the MAF is a pierburg one(I swapped it a week before the chip for performance not faulty replacement)- I will swap it for diag purposes with a known working bosch one.
The glowplug light starts flashing within 30 seconds of the ignition coming on, this is the same time period as when you actually start the engine.
The error is
17970 - Quantity Adjuster (N146): Upper Limit Reached
P1562 - 35-10 - - - Intermittent
Readiness: N/A.
Thanks

 

[inigoj]

These kind of problems are a pain to track down.

If you suspect the Upsolute software, do you have the original Hi/Lo plcc32's to swap back over for testing (i presume its socketed).

Failing that, i would double check the IP timing, and the fuel & coolant temp sensors.

Have you checked for simple things, like a bulb out?

Hope it is not a pump problem.

 

[jameshughes1974]

Hi
The two chips were soldered on by Simon Coe (CCC tech/upsolute), He has done a very good job of the soldering. If it comes down to it I will ask simon to send me the original PLCC's back and I will socket the board myself- This wont be a problem as I used to be in the electronincs industry and have the required skills.

The fuel and coolant sensors would appear to be giving the correct readings.

IP -- Injection Point?
Pretty sure the brake lights are working (will check for sure)
I have also posted on the Upsolute site somebody has said it may be the quantity adjuster itself is sticking.
I think I am going to get the special three sides socket to undo the top of the pump and have a look.
I can only find them on American websites so shipping may take a while

 

[jameshughes1974]

I checked the fuel quantity after the drive to work
The readings are
revs= 861
injection quantity = 3.8/4.0 mg per stroke
voltage = 1.620v
temp = 80.1c

These look ok to me (assuming temp is the coolent temp!)
I have just ordered the special tool to take the top of the pump off.
Think I will also get some PLCC sockets and ask Upsolute for my original chips back for diag purposes.

 

[jameshughes1974]

I have just received the special tool for this job so will be taking the top of the pump in the next few days.

 

[jameshughes1974]

I think I have fixed it.
I scribed the top of the pump then opened it up.
I completely removed the electronic top of the pump from the car.
Note that this does spill diesel as the pump is still in situ.
I moved the quantity adjuster and felt mechanical resistance toward the end of travel.
A few repeated end to end rotations got rid of the mechanical resistance.
I then gave the underside of the circuit board a sustained blast of WD40 into a clean plastic tub.
What came out was a small quantity of black wet “dust”.
The conclusion I have come too is that one of the injector leak back pipes I changed because it was visually degrading must have lost some of its innards as well. I didn't jump to this straight away because the accused pipe was actually changed about 40000 miles ago.
I put the pump back together lined up my scribes and cranked the engine.
Started first time, no glow plug light and no hunting at idle.
I took it for a run and it doesn't seem to have shudder but I was giving it high revs to see if it would trip into limp home but it didn't.
I haven't had time to adjust the injected quantity as when I had vagcom connected the coolant temp wasn't up past 80
The injected quantity was up at 9mg/stroke – I will pull this back with vagcom on a hot engine.
I cleared out the fault code and it hasn't comeback.

So its pretty much case closed
It wasn't the upsolute chip and I am glad I refrained from pointing the finger to much, perhaps the chip highlighted a problem quicker than stock which is why the chips sometimes get the blame for this.
I will give another update when the injected quantity is back in the 3-5mg range just to finish off the diagnosis.

 

[jameshughes1974]

Hi
The fault came back!
But I have fixed it. The fuel pump was genuinaly faulty. I swapped out to a stock ecu and the fault remained.
I have changed the pump and the fault has stayed away this time.
I think the old pump had been degrading over time with out me noticing as the new one seems to have changed the way the car feels in a good way.