That's a challenge. These comments apply to the 240D/300D diesels, your
motor is probably similar in principle but you need to get its actual
specs. So at best consider this as an overview.

I'd check the chain's tension - is the chain taught or sloppy.

(I'd also check the peening quality of the new chain's connecting link.)

The 300D motor has a groove cut into the driver's side of the front cam
support (C/L of camshaft); it also has a notch cut into the thrust
collar immediately behind the chain's cam sprocket. The cam is at TDC
(000 degrees) when the notch and the groove are aligned. One then reads
the crankshaft angle down on the harmonic damper, hopefully it is also
about 000 degrees. Don't turn the motor by the cam and turn it only
righthandidly.

The injection timing of the 240D/300D diesels is in two parts:
The fine adjustment is done by loosening and turning the injection pump
in place; turning the top of the IP towards the motor advances the
timing, away retards.
The more basic adjustment is to remove the IP, set the motor to 24
degrees(300D motor, yours may differ) BTDC of #1 cylinder (check that
#1's valves are closing for its compression stroke) and align the IP's
drive gear's intentionally missing tooth with a groove cut into a ring
behind that gear. Reinstall the IP and the timing should be about right.

The big job here is to ensure that the cam is correctly timed with the
crank. The IP timing can be a separate project.