Hello MB enthousiasts

A month ago i gave my injection pump for a rebuild with new parts and it is soon going to be ready. My question is, how to time it properly when i put it back onto the engine. The crankshaft and camshaft have timing marks but i didnt see any on the injection pump output shaft nor the chain pulley that drives it.

A little help here please can anyone give me detailed info on how to do this right??

1986 190D 2.5 no turbo
5 cylinder with BOSCH mechanical pump
300+ k

Don't know about Mercedes - but on VW the injection pump shaft has a key on it so the pulley can only go on one way. On the outside edge of the pulley (and you really have to look) there is a little notch for the timing. On the top of the pump and on the mounting bracket there are two line markings. When you install the pump all three have to be lined up and a locking pin put into the pulley to keep it there. Then you set the cam and crank timing to top dead center and connect everything up. On the Bosch VW injection pump there is also an internal pump advance timing. There is a bolt on the back middle between where the fuel lines to the injectors come out. The injector pump is then timed using a dial guage screwed into the middle hole I described and the pump moved back or forth on the mounting bolts to get the correct timing then the mounting bolts are tightened. I don't know if both systems are similar - but hopefully this info will be of help to you.

Thanx for that info but the problem is my pulley can go in in many directions because it doesnt have a lock or somthing that prevents it for being put incorectly

Then I would wait for the pump to come back and there has to be a timing system on it for correct timing where the timing is set before the pulley is attached. Sort of like the camshaft on a VW - where you lock the cam shaft at top dead center with the slot at the end of the cam and once everything is ready and timed to put the timing belt on - you just put the pulley on the other end of the camshaft and tighten it and remove the lock. I strongly suspect a timing method that is on the pump itself. Don't fret until you get it back.

Yes probably you are right ... Thanx for the advice


I'd kill myself if the car doesnt run good

First time I did an injection pump - felt the same way - scared the hell out of me! Patience and doublechecking everything is essential the first time until you get the hang of it. Then - before starting the car - I'd turn the motor over two complete revolutions by hand feeling for any unusual tight spots and then check the timing again before trying to start it. If you are off - you won't do any damage by hand turning as opposed to starter whipping. Good luck - and remember - what you will learn by doing it once - you will probably never use again - Murphy's Law!! As you can see from my signature below I have a few of cars to maintain (two kids plus wife's car)! But it is a lot cheaper than taking it out to get done!

Try the Diesel Discussion forum.

On my OM603 which is pretty much the same engine as your OM602, there's a port towards the rear of the IP that lets you insert a lock which holds the pump to the housing. The lock engages when the crank pulley reads 15-degrees ATDC of #1. If the IP is off the engine, you'll have to pop the valve cover to be sure it's ATDC of #1.

If I understand the manual, you have to turn your engine to 15-degrees ATDC and install the IP with the lock in place. That should get you as close as you can without the mega bucks electronic timing tool.

Sixto
91 300SE
87 300SDL