What's the right timing tool for the 616 engine?
 

I find the 601 589 05 21 00 tool, but the description at

https://www.samstagsales.com/mercedes.htm#fuel

says it's for the 617 engine. I believe my '83 240D has a 616.912 engine.

I think it would work on a 616 but I'm not positive. I've installed pumps with and without the tool. IMO it isn't absolutely necessary.

Drip timing after installation is important.

Sugar Bear, I think with all new timing chain, etc, using that timing tool would let you bolt the pump on and have it correctly timed. On our more-or-less worn engines, the drip method lets us compensate for the wear.

Do I have that right?

If we are talking about the same tool it prevents the pump from moving once the marks are aligned on the front of the pump, I don't recall having a problem with the pump moving during install. If the pump did move you would know when trying to drip time.

Drip timing should be done with both new and used parts as it makes the pump timing precise. Without drip timing it will run but after all that work it gets the engine finely tuned vs just running.

If it is what I think it is the fuel injection pump needs to have a port for the tool and of course you need the tool. It is a locking pin for use during insertion of the fuel injection pump.

However, there is other timing tools like the A&B light and other methods that use that port. Also, the reading is different. The reading on mine is after top dead center of the compression stroke.

The timing locking pin is a static method of timing that does not compensate for wear inside of the fuel injection pump.

As far as the fuel injection pump is concerned the drip method compensates for timing chain stretch, timing gear wear and internal fuel injection pump. wear.

Back to it. To use a timing locking pin the governor body on the fuel injection pump has to have the M18x1.5 metric threads port for that.

On the little VW Rabbit I used to have, there was a plug and a dial indicator with a fixture to hold it for timing. It was easy as could be. I wish my Stanadynes and this Mercedes had something so well thought out.