If you do not have a 0.4 bar fuel pressure difference between fuel distributor chambers or you dont read near 0 mA (-2 to 2 mA) on EHA at iddle with warm engine doing the procedure bellow:viewtopic.php?f=48&t=6380
This sequence of tests may help.
Start to check lambda with a multimeter
Read contacts 2 (ground) and 3 (kat) on diagnoses connector at engine bay. Correct read is near 7.5 V (alternate ) for trucks with KAT RUF chip and 6.5V for trucks with ECE RUF . Always with warm engine at iddle. Test also O2 sensor ,the test procedure and reference data is on one of the files bellow .
If lambda is ok and Eletrohidraulic actuator shows strange values , go ahead checking the other sensors.Sometimes only cleaning them can solve the problem.