Grettings all,

I have a 1984 300SD with 263,000 miles. I want to check the injection pump timing. The chilton manual states that diesels prior to the '84 model are set to 24 degrees BTDC. It states that for the '84 300SD, timing is at 15 degrees ATDC. Is this correct?? It seems that after top dead center is way too retarded for the timing. The manual also states that the 190D is set at 15 degrees ATDC. is this a misprint? What are the actual specifications for the timing on the '84 model 300sd? Thanks in advance for the help!

Nolan

I believe that the difference is the METHOD by which the timing is checked. If you use the drip method, it is set a 24...If you use the special tool, it is 15. I will see if I can look this up for you.
Don't hold me to it.

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Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Thanks Benzmac,

The chilton manual didn't mention a method...just a chart for the timing of all the different Benzs. For the 300SD, years prior to 1984 were set to 24 BTDC and the 1984 model was set to 15 ATDC. The real specs would greatly be appreciated...thanks again!

Nolan

1982 240D 258,000
1984 300SD 263,000

Injection timing is 24 BTDC. This is the same as 15 ATDC.

ATDC method: Position engine at 15 ATDC with no.1 piston at power stroke. Open the plug at the left side of the pump governor, rotate the pump's drive shaft so that the pointer on the governor weight aligns with the hole, lock the shaft at this position by installing the tool "Bosch or MB", then mount the pump. Remove the locking tool after the auto-advancer has been bolted to the drive shaft.

Final timing can be checked two ways:
1) Spill method: It will come out as 24 BTDC.
2) RIV method: You'll need to install an MB electronic tool to the hole on the governor housing. Turn the engine while observing the two lights on the tool. Pump is properly timed if both lights on the tool come on at 15 ATDC.

So, 24 BTDT spill method = 15 ATDC, RIV method.

Hope this helps you.

Thanks poptest, that helps tremendously. That manual doesn't state any kind of method to check timing. Good thing I decided to look into it some more before I started to mess with it.

Nolan