Anyone know how to adjust idle speed on a 87' 300SDL ??

[FL70CAT]

Hi all,





I adjusted the aneroid the whole way out so far and I am ecstatic with the wonderful results!! Man that car has a TIGHT converter!!!



My question would be how do I adjust the idle speed so I can twist the fuel delivery a little... I have already found the screw on the back of the pump for doing so.

 

[LSMITH]

Do you have the inline 6 with the aluminum head? If you do put the aneroid back at least part way and don't turn up the delivery, the head will not take any additional heat. The 5 cyl 3L will take a lot more.



Do you have the inline or rotary pump? I have seen both in that era. At any rate they are both bosch pumps and idle adjustments are standard types. Idle screw and if necessary gov springs.

 

[FL70CAT]

It is the straight six and it uses the inline pump.



I looked all over for an idle screw and couldn't find one???

Is there an exact location you can steer me to?



I'm not going to turn the aneroid back. It's not like it raised the max fuel delivery... .....

 

[LSMITH]

FL70, the idle screw on the pump should be on the back under the aneroid. I might be able to get a manual this weekend that would cover that pump, not sure if the guy still has it. Let me know if you don't find the idle screw.



I realize that the aneroid did not increase max delivery, but it did increase fueling at max torque, which raises cylinder pressures. The aluminum head 6 is notorious for head cracks and head gasket failures. Not trying to be a jerk, but telling you what I know. The 6 will not take much more cylinder pressure than what it came from Mercedes making.



If you have the iron head 6 we are taking about another animal. It can be tuned up rather nicely.

 

[Barry]

The SDL is a rare animal and is already fairly warm from the factory. That little turbo six is a screamer! Take good care of it.