VP37: ATDC 17.4° - Power Loss Issue

Hello everyone,

We are having a problem with a 1Z-90PS TDI engine (manufactured in 1996) that is currently installed in a T3 vehicle.

Since a certain point in time, he has experienced a noticeable and sudden loss of performance. According to the VAG-COM diagnostic tool, the injection timing is completely out of sync. However, it cannot be adjusted. Rotating the pump does not result in any changes to the injection timing.

For example, if you log ATDC data while driving, you won't see any changes in the mapping.

The error log indicates that the pump can no longer be adjusted.

When looking at the engine control unit (ECU) data, specifically the injection timing values for each cylinder, these values do not change.

Boost pressure is okay.
MAF ok.

The timing belt, including the timing belt pulley (the front surface of the crankshaft was machined), was replaced using VAG-specific tools.

I suspect there might be something wrong with the pump. However, I haven't found anything about a constant ATDC value so far.

Does anyone have any ideas?

Best regards, Gunnar.

Hello,

Quote:

The error log indicates that the pump can no longer be adjusted.

Okay, then you should check the cable to the solenoid valve of the fuel injector and the valve itself. If the pump is properly adjusted (in the correct position), there's likely an open circuit somewhere.

Best regards, Rainer.