AKE woes, VAGCOM IQ querey.

[TurboSteve]

Why would the VAGCOM Actual Injection Quantity be much lower than the Driver Requested Injection Quantity.

I have MAJOR power issues with a 2002 Audi allroad 2.5 TDi Quattro AKE engine.

Absolutely NO throttle response for about a minute from cold, and low power (only about 40 of the 180 horses) once warmed up.

There is very little specific info about the 2.5 V6 anywhere.

[TurboSteve]

I went for a spin this afternoon and upon returning, while the engine was hot, I tried to alter the IQ at idle to see if this improved matters.

I VAGCOMMED with login code 26262 (took me a while to find this code - everybody else seems to use 12233) and interestingly, although the test and save features were working, and the five digit numbers stayed saved - the injection quantity at idle did'nt change at all.

If i stamp on the throttle - when in gear, or when parked up - sometimes the revs 'top out' ; sometimes at 1800rpm, sometimes 3500rpm, sometimes 4000rpm.

What on earth is going on?!

[adamss24]

Stop playing with the IQ in VCDS, what's the requested IQ and the actual IQ at iddle in measuring block 04....

[TurboSteve]

From memory, the requested IQ is 0 (zero) and the actual IQ is 6 or 7 mg/st - it settles down to this figure once it's warmed up. on warm up, it can be anything between 2 & 9.

Also, there is a distinct tone change in the engine at about 2000rpm (but no performance change) - sounds like a timing alteration - I'm thinking maybe it's the 2nd stage of the two stage injectors activating.

I'll check the numbers in the daylight and report back - any other channels/blocks that you think i should note?

[adamss24]

The timing is too far advanced mechanicaly ! Lower IQ means higher injected quantity and it only shows the ammount leaked back. So higher number means lower IQ...if that makes sense ! Also, do you have the traction control and ABS light popping up on the dash when the car looses power ?

[TurboSteve]

Funny you should mention timing - I was contemplating moving the timing around a bit to see what happens.

However, VCDS TDi checker shows the current timing to be spot-on, and i mean dead on the middle line. When initially set up using locking pins, the timing was ever so slightly out of tolerance on the advanced side-but only just.

ABS/Traction control never illuminate while driving. The car doesn't loose power - it doesn't start with any!!!

[TurboSteve]

Right then:

Group 4 ...........2.0 BTDC Specified Start and 2.0 BTDC Actual start

Group 15 ..........0.0 mg/st Spectfied Injection Quantity and 6.6 mg/st Actual Inj Qty

While revving the nuts off the engine while playing with VCDS, the ABS/traction lights flashed briefly - the engine was changing tone and revs of it's own accord just prior to the yellow lights.

Error codes 00575 and 00500 have been logged.
these are Intake Pressure Limit Not Reached and Start Of Injection Implausable Signal.

what do i do next?

[adamss24]

Which measuring/basic settings block you use for checking the timing 00 or 04 ? Also, is the engine fully warm when you check the timing ? I actually set the timing a little more advanced as the vcds requires as most times the pump belt/tensioner stretches or slips and will retard itself after a while, in your case i either suspect a pump on it's last legs or bad timing...

[TurboSteve]

Timing was checked using the TDi Graph feature of vcds - if you try and do it in Group 00 it redirects you to use Group 04 (or vice versa - in either case you can't get it wrong). then i selected the engine code (AKE for me - it's the bottom option). Checked with the engine at 89.2'C. stay away from the throttle, and timing settles down on the blue (middle) line - smack on spec.

I have mechanically retarded the timing today, just to see if performance changes - it did, and performed progressively worse with more retardation. Eventually i stopped when revs wouldn't exceed 3500 and engine getting noisy. I will try similar incremental changes tomorrow - but with advancing instead.

Diesel Injection Pump is three months (<2000 miles) old - P.B.Ashers Recon Exchange unit, with new EDC Pump Driver - so seriously doubt (and hope) that it's not the problem.

What's the score with this new ABS/Traction Control light flashing issue.

By the way admass24, thank you for your input - it is very much appreciated.

[adamss24]

If the pump timing is ok and the car starts fine then look at the pre cat and main cats for blockage. I suppose you checked the turbocharger is not clogged and actuator's arm moves freely ? Use basic settings 11 in the engine, the solenoid should go from full boost to min. boost and you can see if the arm moves all the way ! I have seen a gt20 turbo which had melted vanes due to high EGT which could not move the arm all the way hence low power and hesitation !