I have 1990 Mercedes 560 SEL. I recently replaced the hydraulic suspension pump. I took off the distributor so that it would be easier to get access to the bolts. I was careful not to move the distributor rotor, but I must have moved it because now I can't get the car to start. So I then aligned the pointer on the timing chain cover to TDC mark on the vibration damper (the big zero right ???) I aligned the rotor to the notch on the distributor housing. still won't start I aligned the pointer to the TDC mark by using the ignition switch to turn the motor. The pointer wasn't exactly on the TDC mark, but it was pretty darn close. How can I turn the engine manually so that I can align it exactly? I read that I should turn the crankshaft bolt. Where is that? Can the rotor be the issue? The car started like new until now.

Thanks and Merry X-mas

I don't have that car but this seems like a basic issue. First of all, don't fixate on the distributor since you might have disconnected something else so don't get tunnel vision. However, you could be right. Now remember that TDC occurs twice, once on the compression stroke and once on the exhaust stroke. You want the compression stroke. If you are on the exhaust stroke then you will be 180 degrees off and it won't start for sure. I did that once...

As for the crank bolt, it is in the middle of the crank pulley on the front of the engine. Usually you need at least a 1/2" drive ratchet for leverage and a short extension to get to it but again I don't have that car so I can't say specifically.

I don't know about the marks on that car but generally you align the pulley to the 0 mark and then move the distributor cap so the rotor points at the electrode for wire #1.

Hope any of that helps.

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Welp, I guess I can spend this christmas under the hood for a few hours. Thanks for the tip mpolli. I guess I was 180 degrees off like you said because I set the TDC at zero, and I aligned the rotor. I will try to find the crank bolt and set the TDC manually. How do I know if I am on the compression stroke without taking off the valve covers ? Also, what are the two U-shaped cutouts on the vibration damper for?

Well I don't have a clue about the cutouts. You might try searching. As far as the compression stroke, well you could just try moving the cap 180 deg and see if it starts. Or you could remove the #1 plug and see which time it makes compression (pushes air out). A compression gauge would be handy for this but you could probably just feel it with your finger (turning the engine slow with the ratchet!).

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Turnng the cap 180 is probably not possible. You will need to remove the dist. and rotate the rotor 180 then reinstall. gEt it close then put on the timing light and twist the dist body until you get the timing just right.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

There is no timing adjustment on a 560. The timing is determined by the crank sensor on the flywheel. Rotating the distributor doesn't change the timing. It can misalign the outputs though. You will note how wide the rotor tip is, that is so it isn't critical where the rotor is when the spark is created as long as the rotor tip is generally pointed at the proper plug wire.

The cut-out are for balancing.

The way to tell if you are at TDC #1 would be to take the valve cover off the right side and look at the cam lobes on #1 cyl, but that is too much work. You either are right or one turn of the motor wrong. Either find that bolt in the center of the harmonic balancer and turn it or take the distribiutor out and point the rotor 180 deg from the #1 position.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

well, looks like the crankbolt is the easiest way to go. the TDC line has to align PERFECTLY with the tip of thetTiming chain cover. The hydraulic pump is finally fixed what a relief. thanks for the help and info