Electric Circuit ECU-SENSORS, GOL 1.9 SD 2000

Hello forum members, I need the ECU-sensor wiring diagram for a 2000 VW Gol 1.9 SD. The problem is that the engine is smoking between 1200-2000 rpm. I detected by measuring the voltage at the fuel pump that it's advancing earlier than expected (it should be progressive), but at 1500 rpm it's only at 10-11V. If anyone has any ideas, I have the wiring diagram and could send it to you.
Thank you very much.
Jorge, General Pico, La Pampa

Good. It doesn't smoke when the timing advance is too high, but it does when it's too low, emitting bluish-white smoke. If you check the pump timing with a dial indicator, measure it from the beginning of the camshaft disc's stroke (0.90mm ±9), considering top dead center.
Another possibility: check the EGR valve isn't malfunctioning. Another possibility is that the pump isn't getting enough diesel, preventing the hydraulic advance from working. Change the filter and clean the fuel lines with compressed air.

Below the pump is an electric advance unit controlled by the ECU and the four-pin coolant temperature sensor. Disconnect the temperature sensor while the engine is running to see if there's any change. I'm not at the shop right now and I don't remember how to test it. Good luck, and don't forget to post how it goes

Thanks SAN for replying. It could be that it's lacking timing advance, which is why it's smoking. It does this between 1500-2000 rpm. I disconnect the timing advance connector and the engine runs perfectly, without any problems. That's why I think there's a broken wire or a sensor malfunctioning in the ECU. The large connector on the cylinder head is fine. We'd have to see which wires go to the ECU and test them. That's why I need the wiring diagram. The mechanic and the fuel pump specialist say there's no problem with the pump. I took it to an electrician and they told me it was the pump???????? I'm an electronics technician and I think the problem lies in this area. Thanks