MB OM366LA (356989) 1995 177kw engine loss of power.

[johnbrooks]

May I introduce myself to this forum with a novice question (sorry, only speak english)... Can anyone tell me how to check the angle of my diesel pump, I am told it should be 11deg before top dead centre?

We had a service in Peru, before the engine would produce power from about 900rpm and tail off by 2500rpm. Now it does not produce power until 1600rpm and will (I dont of course) pull well into redline and runs hot and badly. I guess it needs retarding, does anyone know; do I turn the pump towards or away from the engine block and by how much?

Any advice would be greatly appreciated.
John

[Tasmane]

Hello John,

if you pull the pump "away" from the engine, the injection point is earlier. 3° is ca. 2mm !
You should mark the original position before, than you can remove the change if there is no improovement.
Could you describe what the Peru service did exactely ? Did they touch the pump ???

Best Regards,

Tassilo

[johnbrooks]

Thank you for the reply. Its a long story, in short; Peru sent the pump and injectors to a 'laboratory'', I was told it was normal to service these parts in this way, of course this is incorrect and a big error. The laboratory did not have the pump data sheet and made a mess, also the fitting of the pump was a guess. We made it to Ecuador where we went to a Mercedes dealer, they sent the pump to Bosh and it was set to factory settings. But the workshop were not sure on the angle to fit the pump back so guessed it. The engine runs badly, rough and power only up at red line. I would like to set it correct myself. I asked the Ecuador workshop to set the pump to 11 degrees before top dead centre, but they did not seem to know how to measure this, do you know this?

The problem is compounded; they did not only "service" with the pump but other things, so it is hard to track down the problem. Valve tappets set totally wrong (set correct in Ecuador), they removed and disposed of our spark arrestor - this may explain the rough sounding engine?

Many thanks

[Tasmane]

if you pull the pump "away" from the engine, the injection point is earlier. 3° is ca. 2mm !

Sorry, I have to correct this ! Push the pump to the engine, than it injrcts earlier.
You can remove the first injection pipe on the top of the pump and turn the engine by hand slowly. Then you can see the injection point.
At this point you have to take a look to the mark on the crank wheel. There is a scale !

Good luck,

TAs

[unihell]

Hello

if you pull the pump "away" from the engine, the injection point is earlier.

that´s right. Crankshaft rotates right, camshaft left and injection pump rotate right, so if you move the injection pumphousing against rotation, the injection point is earlier.

For the injection point you will find the mark at the vibration damper on frontend of the crankshaft and a pointer at the engine housing. If the mark matches the pointer, you are in the injection point

[johnbrooks]

Thank you very much. I rotated the bump towards the engine by exactly 1mm and the change is enormous - I would not have expected such a small rotation to make such a big difference, it runs well and the power is back down the rev range. Thank everyone for your help.