Ignition Timing Help Desparately Needed

[seabien]

I have 1981 380SL. The water pump died so to save money I replaced it myself. I needed to remove the distributor in order to remove the water pump but I did not mark the timing plate or the location of the distributor rotor before I removed the distributor. (this was my first time repairing a car and didn't have proper instruction) The the new pump is in and the engine is all back together but the engine will not start because i rotated the engine a few times by hand while the dist was out to get the belts off. can anyone walk me through the procedure for getting the engine back to TDC? The block has a pin sticking out of it on the right side just above the timing plate. the timing plate has a pin sticking out of it also. Do I need to align these two pins or do I align the 0 mark on the timing plate with the pin sticking out of the block? Additionally need to know where to align the distributor rotor and what to do with if the engine wont start after all is properly aligned? Please help Best Regards James

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[jnappi]

Hi, although I am not a mechanic, I see that no one posted to your question. First you have to ID the number 1 cylinder. On my 1985 380SL it is the first cyl on the left side looking at the engine from the front. On American cars, this is typically on the right. next you have to bring the piston in that #1 cyl to TDC. The piston will reach the top of the cyl twice, once on the combustion stroke and once on the exhaust stroke. I am not sure how you will cycle the engine, but I haveheard that people do it wih a special wrench mounted on the crank shaft. You can also cycle the starter motor. There is a o tool that when inserted in the spark plug hole, will tell you when the cyl has reached the top of it's travel. Obviously the combustion stroke will have pressure and both valves (exhaust and intake) will be closed. With the piston at TDC on the combustion stroke, you have to align the rotor to the number 1 spark plug terminal on the top of the distributor cap. You can place a chalk mark on the side of the distributor where the #1 plug is to help you align the rotor. If the distributor has a spiral gear, this will be a trial and error procedure, as the distributor has to be inserted off the mark then it will turn towards the mark. If the distributor has a slotted gear, there will only be two ways it can be installed. I don;t know what the case is here. Once all this is done, the car should start and then you can time it to spec. I hope that this is clear.

[seabien]

Joe, Thanks so much for the information. I am going to follow that proceedure tomorrow. Keep an eye out for me. I may have more questions. Thanks again for the info.

Best Regards

James