M129 Specifications under load

[dario]

Hi Forum Members,
For the last week I try to fine tune up my early 250SL engine. There comes the time to start the road tests.
Unfortunately I dont have first edition of the BBB, which contains the man. specs. for my engine.
If one of the owners of this book would be so kind to read this numbers for me, it would be very appreciated (maybe scan of the whole sheet ? ).

Probably is:
Engine revs; MAP Pressure [mmHg]; CO level [%]
1500                200 ?                          ?
2000                200 ?                          ?

At idle 3,5 - 4,5 %? Any other special operating parameters (WOT, idle on gear, other...)?
Thank you in advance for any help.

BTW it would be very helpful for many members, when this specifications could be put in an ordered form (for every engine) to our Technical Manual.
(or I simply can't find them)

Dariusz

[jeffc280sl]

Hello Dario,

If I recall correctly the MB tech manual describes on road specifications for a manual transmission.  Do you have a manual transmission?  Have you installed a MAP sensor and purchased a portable device to measure air fuel ratios under specific loads?  I wrote about this subject some years ago.  Before you touch the pump settings address all other related areas.  Have you examined the barometric compensatory operation?  I wrote about this device as well.  My original was bad.

[jeffc280sl]

Hi Dario,

Here are the on road dyno tests for various fuel injection pumps.

[jeffc280sl]

It has been some time since I looked at these specifications.  As I review the specifications today I noticed it refers to testing in third and fourth speed.  Not gears as I had thought earlier.  I suppose this means that tests can also take place with an automatic transmission.

[dario]

Welcome back after weekend,

Jeffc280sl, thank you for your comments and attached scans. They will be very helpful. I read of course your thread about AFR adjustments, it was very inspiring for me.
In my car I installed (temporarily) the LM-2 wideband sensor with rev. counter read directly from ign. coil.
I plan to buy MAP sensor (BTW: do you know one with direct 12V power supply to not have to change voltage from 12 to 5V as mostly MAP Sensors work?) - my probably will be from Seat/Vw (11,7 to 117 MPa range wchich is transformed to 0,25 to 4,75 Volt output signal.
The manufactury specs. are current for both manual and auto trans, I suppose (as you mention - 3rd speed is important). I'm afraid only that your data relate engines after 1968 and my is early (1967) 250SL. Hence my request for data from the first volume (before 1968) which I don't possess.
Thanks a lot anyway.

Dariusz

[jeffc280sl]

Hi Dariuz,

Very nice to hear from you.  I recall going to a junk yard for the MAP sensor.  I believe it came from a BMW.  Not sure about the input voltage.  I can't remember if I had to tackle this issue.  I will look into the earlier manual to see if there are any on road dyno tests.  Did you check to see if your pump was by chance on the list?

I'll let you know if I find anything.

Best regards,

Jeff

[jeffc280sl]

I was not able to find anything on the 129 engine in my documentation.  Your FIP should be an 18, 18z or 18y model.  I'll keep looking.