1965 230 SL Gas Injection Pump

[Derm Cain]

Recently I had the engine removed from my 1965 Mercedes 230 SL.  To remove the engine the mechanic removed the pump linkage, where the linkage attaches to the pump.  The Injection Pump was not removed from the engine.

The engine was removed and turned in various positions for detailing and new gasket installation.

When the engine was installed and the car started, the injection pump has a rattiling noise in it at 2600 - 3000 rpm's.  It seems to come from the rear of the pump upon acceleration.

Any suggestions or literature on the Injection Pump would be greatly appreciated.   

[Benz Dr.]

I think you should check the oil level in the IP. Oil could of run out when your engine was moved to various positions and now it could be dry. I hope you didn't damage anything. 

[Derm Cain]

I had a post on earlier with regard to the Injection Pump on my 1965 230 SL.  For some reason it has disappeared.  Sorry I am not overly familiar with the site.

As I previously said;  The engine was removed from my car for detailing and gaskets changes.  The injection pump was not removed from the engine.  The person who removed the engine removed the linkage from the pivot (or arm that extends from the pump) to change the seal (o ring) on the.   The engine was moved in different directions and angles to do the detailing and gaskets.

When the engine was installed and started there was a noise in the rear of the pump.  When depressing the linkage on the pump, the seemed to hook or ctach when being depressed.  Oil has been check and was ok.

Does anyone have any experience   or know an expert on these Injection Pumps.  Anything you have would be helpful at this point.

PS;  Anyone has any suggestion on how my original post got lost.  I am reasonably sure I didn't delete it.

[Peter van Es]

PS;  Anyone has any suggestion on how my original post got lost.  I am reasonably sure I didn't delete it.

It's not lost. It was just in the Drive train, fuel, etc... board where it belongs.

And you got an answer.

[Derm Cain]

Checked oil and it is good

[ja17]

Removing the pivot, or lever on the IP is a big mistake. You cannot get back to the exact factory set location of the lever. You will need to get lucky with a guess or must send it out to a IP rebuilder.

[Derm Cain]

thank you.  I live in Newfoundland and Labrador, Canada.  Anyone know where the closest IP Dealer is?

[Cees Klumper]

The only thing I can think of to check is the idle mixture screw/knob on the back of the pump. If the idle mixture screw inside the pump is adjusted too far out, it will permanently engage the knob, which will spin with the engine rpms when it is not supposed to. Check if the knob can spin freely with the engine off. If it engages the internal screw, then the screw is too far out. It's a long shot but worth a try.

[Derm Cain]

I am still having issues with the Bosch Gas Injection Pump on my 1965 230 SL Mercedes.

I have reviewed the information in the SL Group Technical Manual.  Would anyone have further information, scamatics, drawings, parts breakdowns or video on disassembly and repair of the model pump.  I will attach below a picture of the Pump Numbers.  The issues with the Pump seems to be in the governor / governor weights that may have fallen out of place when detailing the engine.

Pump Numbers:  PES6KL70/120R11;  11U35781
Once again thank you to all for your comments and information.

[Charles 230SL]

hello Derm, sorry to hear about your R11 pump situation.

As you probably already know, the governor section will need to be opened up; attached is a picture of the governor with the back plate removed - the weights are clearly visible.

I replaced some seals in my R11 governor several years ago and attached are Bosch diagrams I referred to when I had it apart. The attachments include a diagram of the governor section and of the pump itself.  hope this helps, Charles

[ja17]

The problem when you take the lever off the side of the pump, the lever is not keyed onto it's shaft. A spring then moves the shaft out of calibration. Now you have no way of telling where the original position is to install the lever.

[Tyler S]

As Joe states, the lever shaft is spring loaded. When the lever is removed, you are effectively removing the stop as well. The governor shaft and 3D cam then travel too far and the stylus ball rolls off the end of the 3D cam. This is most likely what you are feeling when trying to depress the linkage. You may get lucky removing the pump, rear cover and look to see where the stylus originally traveled on the cam. You can then preload the governor and reset the lever and stop in their proper position. This may get the car running correctly but you will most likely need  to send the pump in for adjustments.