Mercedes OM616 OM617 OM615 engine setting the injection pump timing
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- Опубліковано 22 сер 2024
- Mercedes OM616 engine. I was trying to fix the hard starting. I had to like preheat 2 minutes, and try 3 to 4 times to start and sometimes it drained the new battery so hard that I could not start the engine at all. I started by doing the valve adjustments, at the same time I took out the injectors to have them inspected, they said they were not good, so I replaced the injection nozzles. I also too out the Bosch injection pump and had the manual pump changed. Now upon putting the Bosch injection pump back, setting the crankshaft at 24BTDC and having the mark on the injection pump teeth aligned, the engine would not start at all! Now, each time. you take out the pump for timing and getting the air out, each time it's close to taking 45 minutes. Now my mind started to play with me, about the degrees, at second thought, I adjusted the timing to 28 degrees, for chain slack, but nothing. It took me literally 2 full days from taking the pump out and back. I was getting desperate and spoke with a Mercedes garage to have it possibly towed to them. But they said at 24 BTDC it should start. Here is the key: From day one I thought about the chain slack, but nowhere online is anyone giving a solution, There were some forums were people were asking, but the answers were always beating around the bush or straight: "you have to replace the timing chain" and nothing else. I was considering to change the timing chain, but not right now, why could no one give a straight answer? So after not listening about the 24 degrees BTDC and do my own thinking I came up that when I align the cam shaft marks and check what I read on the crankshaft, in my case 6 degrees AFTER TDC (+6 degrees) and - 24 degrees is 18 degrees. As soon as I did that, the engine started right away. Now with the new nozzles and valve clearances done, the motor starts the way it supposed to, little preheat and starts with the first crank. I was also almost going to replace the starter motor thinking that it did not rev the engine strong enough to create compression. I am telling you, after a while your mind is playing with you. Another tip is also to really write down the previous teeth positions of the injection pump and what you tried before because you forget what you did after doing so many adjustments. Anyway, thanks for watching.Your opinion is appreciated.
After you turned the crank to get flow to #1 and reached flow, what was the crankshaft reading? Thanks.
Before starting, I was 6 degrees over and had to be at 24 before. So i got it to work at 24 minus 6 = 18 BTC
@@makingcookingfixing I’ve got mine at 24/25 btdc and now I take off the pump and align the marks and place the pump back on. At this point since being at 24btdc with rabbit ears up on intake and exhaust in #1 and marks aligned I should button up and rotate to 15 atdc as I understand. What are your thoughts? I have not messed with the side panel on the pump setting it to 19.5 - I’ve not attempted this yet. Of course at this point I can use trial and error starting at 24btdc. I watched videos recently which also used 15atdc after a formulae had been followed adjusting the ‘side timing.’ Thanks for commenting again.
@@banginbuffalothe first part you write is perfect. 24BTDC bottom and ears up on top, if you took out your pump and the untoothed cog lines up, you should be perfect, this means the pump will spray exactly at 24BTDC. Just do the air removal process by hand pumping. But just to be sure, without the steel high pressure fuel pipes, rotate the crank and see if the diesel actually starts to lift from the first line each second turn at 24BTDC. It should and you should be able to start the engine
I'm sorry that I didn't understand how you fixed the injection timing. Did you loosen the injection pump mounting nuts and then swivel the injection pump towards the engine by 6 degrees ?
Hi, yes, I removed the 3 mounting nuts of the injection pump to remove the pump so I can see the groove on the front gear. In normal cases that groove should be on the top mark on the body of the injection pump and at the same time, match the alignment marks on the camshaft which is TDC Top dead center of cylinder 1. Now the difficult part is determining the amount of chain stretch you have to find the true angle of TDC on cylinder 1. To find that you turn your engine clockwise until the two marks on the camshaft line up precisely! and then look down on the crankshaft pulley and read the number where that is. It supposed to be 24BTDC If camshaft is aligned it means that cylinder one is in compression stroke. and the mark should be at 24BTDC. If it is not there, you look where you are at (before or after 24BTDC and you would adjust your injection pump accordingly.
please also check what I wrote at 4:11 in the video. The quick and easy answer is, align your camshaft marks (make sure they align at the first cylinder, because you could be aligned at cylinder 4 (this is a great tip!) so, open your valve cover to be sure the two rocker arms of cylinder 1 are up, set the sprocket groove of the injection pump aligned with the mark on the body. Then turn your crankshaft manually to where you need to be (which you determined beforehand) in my case, I was 6 degrees after TDC. Any question you have I will try to help.
Thank you very much. Now I understand how you matched the pump timing to the engine timing marks with the 6 degree change due to the chain stretch. ,👍
@@makingcookingfixinghow would you adjust your injection pump accordingly if it read say 18 degrees?
@@banginbuffalo are you sure it reads 18degrees with the camshaft marks aligning at TDC on first cylinder? (Both intake and exhaust lines are up)
Hi friend, i still don't understand how you compensate pump timing without an exact tdc, but it works😂
He accouted for the slack of the chain, apparent by checking how misaligned the crankshaft is to the camshaft at its tdc marks. I suggest replacing the chain though, as 6 degrees is a lot.