280SL 1968 Injection linkage

[Thierry du Laos]

As I have problems to adjust the pump with the air intake. Can any body tell me what is the angle between the lever 1 and 2?



As I have dismantled all to refurbish, now I wonder if the levers can be mixed if they have different angles?
I don't have the quadrant tools to check the angles evolution between the injection pump and the air intake flap.
So I started with the injection pump link  lengh of 23,2 mm.
Surprisingly it exactly comes into contact with the lever 2 bracket structure!!
But then the link from the lever 2 to the air intake lever is adjusted close to its max lengh, when on the idle stop of the air flap lever!!!!!
So that is why comes my question just above. Would I have made a mistake re-assemblying?

[ja17]

On the 280SL, the two levers are nearly identical. However they are slightly different and should not be mixed up. The location of the roll pin holding the brackets in place is in a slightly different location. The quadrant tools are not needed as long as the lever on the injection pump is not disturbed. The critical rod is the injection pump rod which should be 233mm from ball-socket center to ball-socket center. Also make sure that the venturi flap is closed all the way at rest.  Follow the linkage tour to finish up your installation

[Thierry du Laos]

Joe,
I went through those, just can't find the complete tour your are recommending?
I went on youtube, and made the flap adjustment, but then there is many topics on rescuing the car but no more on the linkages adjustment.
So I followed starting from the 23,3mm linkage but then, i am not sure !!!!!!
The engine runs, but not as I'd expected, and I think I have to dig in these 2 levers's angles. And make sure this connection is correct before going further.
I could have mixt the 2 levers, when renewing the assy? Human mistake...!
Thanks.

[kampala]

The linkage tour and starting tour are some of the premium content on this site that you need a "full membership" for.  The links are at the bottom of the main tech manual page:

http://www.sl113.org/wiki/

[Tyler S]

Thierry,  The cross shaft arm ball for the throttle plate rod should line up with a hole that is in the bracket on the intake manifold. The bracket heald down with the 2 bolts and supports the right side of the cross shaft. You can insert a small wooden dowel in it to help line it up. Then set all your linkage lengths to that starting point. Just make sure the injection pump and throttle are both on their stops.
You cant always rely on using the 233mm length to set up.  If the injection pump has been rebuilt or the head has been milled the measurement method wont work.

[ja17]

Milling the head should only make 1mm or less in the rod length measurement and the rebuilt injection pumps are supposed to have the linkage arm, re-set to its original angle.

[Thierry du Laos]

Hi Tyler,
I made a steel tool to adjust lever 2 from that hole. Surprisingly the link at the fuel pump was hard to adjust because the lengh a little shorter than le the link would normaly allow. However I managed milling 1mm the link to make it, but far less than the 23, 3mm!!!
Then adjusted the air flap.
There is still a wao - wao regime that doesn't sound like runing fine.
An other question is that we can adjust the idle from 2 points.
- One is the air screw from the air filter to the air intake.
- One is the intermediate linkage that comes from the pedal, the little one on top of the air intake!
I can't figure out the correct way?

[Thierry du Laos]

Look at this. This is the difference I have between the 2 riggings!!!

[Tyler S]

If you look at my picture, the linkage arm at the intake manifold side has a part number that ends in "0721".
The arm on the injection pump side ends in "0821". Make sure you dont have them reversed. The only other thing that could possibly be wrong is if the stop on the injection pump was tampered with or the cross shaft is bent down.

Idle should only be set with the air screw on the intake manifold and the adjustment knob on the back of the injection pump. Do this last after timing and linkage have been set up properly. DO NOT adjust the pump with the engine running!