Engine Issues on VW PASSAT B6 2.0TDI

[vilijonas]

Hello,


Recently, I underwent an engine swap, installing a previously operational engine from another vehicle into my own. The engine in question is a VW PASSAT B6 2.0TDI with 125kw, ECU Siemens PPD1.2.


Upon completing the swap, I encountered a series of problems that have left me puzzled. The engine starts, but it exhibits a noticeable roughness and instability. Additionally, the RPMs do not rise beyond 4000, giving the impression of the engine being in a "limp" mode.


I have taken a systematic approach to troubleshooting this issue. I initially adjusted the injectors before starting the engine. Despite meticulous adjustments, the problem persists. It's worth noting that the injectors were professionally refurbished and reinstalled.


To rule out any mechanical issues, I conducted a compression test on all cylinders, and the results indicated a healthy compression level of around 25 bar in each cylinder. This suggests that the cylinders themselves are in good condition.


Using VCDS, I monitored the injector values (engine bank 13), and the readings have been quite perplexing. Injectors 1 and 4 seem to be operating correctly, but injector 2 displays a value of -1.8~, while injector 3 shows a value of +2.6~. I have physically swapped injectors multiple times, and yet the values remain consistent.


Curiously, the ecu does not display any fault codes, which adds to the mystery of this situation.


I have attempted injector adaptation through VCDS, hoping that it might rectify the issue, but unfortunately, the problem persists.


Given the complexity of this problem and the various steps I've taken to address it, I kindly request your expertise and guidance. Could there be a specific programming or coding issue related to the injectors that I am overlooking? Perhaps there's an aspect of injector calibration or ECU interaction that requires attention?


I genuinely appreciate your time and insights, and I am open to any suggestions or recommendations that you may have. Your assistance in helping me resolve this issue would be immensely valuable.

I forgot to mention that EGR and DPF are disabled. The DPF was removed before the engine was replaced and remapped ECU file was reflashed before attempting to start the replaced engine.

Thank you for your attention and support.

[Mario6]

I think your problem is not injector #2 but injector #3. It "pours" fuel.

The norm per cylinder is -2.8 to +2.8. However, large values of +2.0 and higher indicate a problem with the injector, cylinder, valves.


If you changed injectors in places and on the third one there is still a +2.3 correction, then you have a problem with the third cylinder, valves, rings.


What were the fuel corrections on individual cylinders after replacing the injectors?


Siemens injectors are piezoelectric and rather non-regenerative.

[vilijonas]

Despite multiple physical swaps of the injectors in different positions, the fuel correction values have remained entirely unaffected. This phenomenon has left me perplexed, as I expected to observe some variation in readings following these swaps.

Could DPF (Diesel Particulate Filter) remapping potentially contribute to the perplexing engine problem I am currently facing? I find myself at a juncture where I am considering all conceivable factors that may have triggered the issue.

Furthermore, I would like to emphasize a crucial detail: the engine in question was in optimal working condition before its removal from the donor vehicle and installation into my own. The issues I am encountering only manifested after the engine was transferred to my vehicle.

Thank you for your time, understanding, and ongoing assistance.

[vilijonas]

I want to emphasize that the engine is stuck in a "limp" mode, and in Neutral, the RPM only goes up to 4000 rpm. Additionally, when attempting to move in first gear, I've noticed that I need to apply more gas than usual. The engine seems to lack its usual power, and I believe that's the best way to describe the situation. Furthermore, it's worth noting that the ECU does not show any fault codes.

[DiegoStud]

Hello,

...and remapped ECU file was reflashed before attempting to start the replaced engine.

Was the engine running fine on a stock file originally? So is it a poor tuning file with all sorts of fault codes deleted and who knows what else messed up?