Need some help solving a engine problem

[mmi]

Sorry for the slow reply, heres the log

Interesting

(1) Why specified fuel pressure value doesn't match the actual?​

The difference is about 28 bars when engine is running. Normally they would be within a few bars.

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[EDIT:] ​

On this engine one should not compare IDE00188 and IDE02228, instead use for comparison IDE00188 and IDE00201.​

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(2) Why there seems to be no relationship between fuel pressure and pressure sensor voltage (when engine is running)?​

Pressure reading seems to quite stable but pressure sensor voltage reading varies - normally there is linear relationship between voltage and pressure. Is engine running in some kind backup mode.

Did you check for fault codes? Is the engine remapped?

Below plotted sensor voltage (x-axis) vs reported pressure (y-axis). Also plotted a line to demonstrate normal relationship (0 bar = 500 mV, and 1800 bar = 4000 mV)

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[EDIT:] on this engine one should not try correlate IDE00188 and IDE03892 Fuel high pressure sensor: unconditioned voltage. ​

The IDE00188 is filtered/dampened data whereas IDE03892 is raw data from the sensor - varying at much faster rate. Instead IDE00589 and IDE03892 will pair perfectly - see post #30.​

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No matter what sensor voltage is, the reported pressure is at 300 bars

Perhaps you could make another log, logging the below.

IDE00021 Engine RPM​

IDE00188 Fuel high-pressure: actual value​

IDE00201 High fuel pressure: specified value​

IDE00352 Main injection: duration of activation​

IDE00589 Fuel pressure​

IDE02228 Fuel pressure regulator valve: specified value rail pressure​

IDE03892 Fuel high pressure sensor: unconditioned voltage​

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Please try ticking the "Group UDS request by 7, or 8" - to see if it keeps data alive (Not sure it works with older cable). The option would greatly enhance sampling rate.

​

 

[Tyrrell]

No it’s not been mapped (that I know of), it was running the TDI tuning box, but that’s now been removed. Could it be it’s still learning the standard settings with it now removed or the fuel pressure sensor needs calibration?

 

[Tyrrell]

Also no fault codes

 

[Tyrrell]

unfortunatly it doesnt let me select 7 or 8 with this cable

 

[Tyrrell]

heres the new log. i did up the revs a bit towards the end. it does smell a bit rich on start up

 

[Tyrrell]

we did drive 2.5 hours yesterday. made it ok, still have the fluctuating idle but its not all the time. feels a bit under powered but thats me driving with out a tuning box, fully loaded with camping gear and on some inclines.

 

[mmi]

Could it be it’s still learning the standard settings with it now removed or the fuel pressure sensor needs calibration?

Workshop manual for Transporter engines CAAA,CAAB,CAAC,CAAE,CCHA,CCHB,CFCA,CAAD doesn't mention need to calibrate or adapt the sensor.

unfortunatly it doesnt let me select 7 or 8 with this cable

Thanks for confirming

heres the new log. i did up the revs a bit towards the end. it does smell a bit rich on start up

Thank you very much!

I'm not sure which parameters we should look into. Now the spesified pressure is somewhat LOWER than "actual". Previously in post #21 it was the other way (specified was HIGHER).

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[EDIT:]
On this engine one should not compare IDE00188 and IDE02228, instead use for comparison IDE00188 and IDE00201.

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Now both "specified" fuel pressure readings were logged - perhaps the IDE00201 is actually the correct one being more stable?



It would also match channel IDE00188 Fuel high-pressure: actual value

still have the fluctuating idle but its not all the time.

Well, obviously didn't happen during logging? As the RPM is very stable (blue in the middle below).



I'm afraid we can't capture much useful with the old VCDS cable as the data samples are 1.5 seconds apart - in the 1.5 seconds in between a lot can happen - as the red curve suggests.

Using the grouping we would get about much better sampling rate.

However, I can't confirm that the CAAC ECU will do the grouping as the capability in VCDS was introduced in April-2017 - and my latest logs of CAAC engine are from March-2017

Perhaps someone with VCDS HEX-V2 and engine CAAA, CAAB, CAAC, CFCA could confirm?

 

[Tyrrell]

mmi thankyou for all your help so far. It’s strange as the van was running fine until the P0192 fault I got typically the day before the trip was due to start. The only part that’s changed is the fuel pressure sensor. So still hoping it’s related to that part not being genuine. When it does start hunting for idle it doesn’t sound like it’s getting enough fuel and it splutters around. It wasn’t doing it in the log above. It seems to idle better from cold.
Now in Switzerland and have again message the local vw commercial garage to see if they can help. As we still have quite away to go.

 

[WillWillWill]

Perhaps someone with VCDS HEX-V2 and engine CAAA, CAAB, CAAC, CFCA could confirm?

Attached log from 2012 CFCA. Can use grouping with the Hex-V2. Doesn't help solve the issue I realise...

Timestamps tie up with a 200ms period/5 Hz logging rate.

 

[mmi]

Attached log from 2012 CFCA. Can use grouping with the Hex-V2. Doesn't help solve the issue I realise...

Timestamps tie up with a 200ms period/5 Hz logging rate.

View attachment 327737

Thank you very much, really appreciate sharing the sample.

Actually helps a lot to understand the fuel pressure data, especially the relationship between sensor output voltage vs. reported pressure.

As by grouping the voltage and pressure reading are read with VCDS HEX-V2 practically at the same moment (below TIME STAMP) the voltage vs. pressure relationship makes now sense - all the data points fall nicely on straight line

 

[Laur]

Hello,

owner of EA189 2.0TDI 103kW CFHC engine here, struggling already a long time with vibrations, and searches in the internet by the IDE numbers have brought me here:

VCDS interprets channels:

IDE00201 High fuel pressure: specified value
IDE00188 Fuel high-pressure: actual value
IDE02228 Fuel pressure regulator valve: specified value rail pressure
IDE00589 Fuel pressure kPa rel
and
IDE03892 Fuel high pressure sensor: unconditioned voltage mV,

I´ve also made a lot of logs to understand what is what, tests have shown that


IDE00188 Fuel high-pressure actual value equals with IDE00201 High fuel pressure specified value

IDE00589 Fuel pressure kPa rel value corresponds with parameter IDE03892 Fuel high pressure sensor: unconditioned voltage mV (I converted mV to hpa, 500mV ~0hpa; 1140mV 322000hpa and so on)

IDE02228 Fuel pressure regulator valve: specified value rail pressure does not match IDE00201 High fuel pressure specified value

In my case IDE00188 and IDE00201 are stable, at idle 322+-2bar, IDE00589 and IDE03892 are fluctuating hand in hand approx 270..320 bar, although upper value never exceeds 188 or 201 value. (as shown in the graph)
Does it suppose to be like that?



Made an another log from low mileage van with 120kW DRE engine, in this case I didn`t find parameter IDE00589 Fuel pressure kPa rel,
but found parameter IDE07819 Fuel high pressure sensor: unconditioned voltage whitch was fluctuating no more than 15mV at idle



I just ordered new Pierburg rail pressure sensor 7.11225.04.0, isn´t it same sensor as in box with vw badges?