G4 AI Upgrade: G3 Conversion, DZM Signal Instability

Hello everyone.

I installed a Golf 4 TDI instrument cluster in my "small" naturally aspirated diesel engine.
Except for the frame and the fuel gauge, everything else is working.

Among other things, there were also problems with the tachometer signal.
Since the 1Y/AAZ engine receives the tachometer signal from the alternator (LIMA), it wouldn't be compatible.
I then took the signal from the "glow plug timer control unit" (simply connected it to pin 1 of the control unit). The tachometer shows the correct RPM, but...

Under full load, the engine speed (RPM) exhibits uncontrolled fluctuations up and down. Since the ESP has a "full load valve," I suspect that a voltage fluctuation or something similar occurs when I accelerate.

Could an electrician perhaps have an idea of what could be done to address these fluctuations?

I would be grateful for any help.


Sure, here's the translation:

"Best regards," or "Sincerely,".

dakoal

Hello,

I always thought that, even with TDI engines, the tachometer signal came from the alternator.
I don't remember off the top of my head whether it's still processed by the engine control unit.
I've also completed the upgrade, and everything is working fine for me.
Is that the AI from the 4-series, and is it powered by a diesel engine?

Hi,

I was wrong; of course, the speed pulse in the TDI engines comes from the MSG .
Sorry, but I can't help you with the problem regarding the speed/revolutions per minute.

Hello.

After the entire engine started jumping in sync with the tachometer, I disconnected the cable from the glow plug control unit. Unfortunately, the engine still "stuttered" under partial load afterwards.
I've now expanded the GZSTG. I'm going to build the frequency divider based on the instructions in the g3 forum, and I'll take the tachometer signal from the alternator (LIMA).

Besides, my little Golf is running better than ever without the GZSTG . So, the electronics are completely messed up, which is also why the tachometer is jumping around.


Sure, here's the translation:

"Best regards," or "Sincerely,".

dakoal

Hi,

Since it was too hot outside to do anything, I took the GZSTG apart in the basement and replaced the blown electrolytic capacitor. Now there's a clean DZM signal at pin 1. Also, the Golf now works the same way with the GZSTG connected as it does without it, so it must have been defective for quite some time.


Sure, here's the translation:

"Best regards," or "Sincerely,".

dakoal