injection pump

[Taleb]

hi all ,
my 1969 pagoda has injection pump model ---R20 does that means I cannot fix another model number such as R24 or R22 ?

[Tyler S]

Yes you can replace a R20 with the later pumps. Have a look at this thread which has a chart showing differences.
You may or may not have fuel cut and enrichment solenoids that have to be taken in account. Any replacement will likely need adjustment.
https://www.sl113.org/forums/index.php?topic=20534.0

[Shvegel]

R20 would be the last pump with the pintle style delivery valves which are prone to leaking.  It would also be the last pump with the enrichment solenoid to help starting.  The newer style ball check delivery valves made the enrichment solenoid unnecessary.

To make a long story short:
The 22 and 24 pumps are better pumps and they will work but they will have one less solenoid (Electromagnet) on the end facing the rear of the car(the right side in the pictures below).  The wiring to the upper solenoid will need to be disconnected and insulated by wrapping with electrical tape. 

R20 here     https://www.ebay.com/itm/MERCEDES-280-SE-SL-BOSCH-FUEL-INJECTION-PUMP-R20Y-113-111-280SE-280SL-MECHANICAL/382258163908?epid=1248518783&hash=item59005cb0c4:g:7ssAAOSwUUdXEBot&vxp=mtr

R24 here:    https://www.ebay.com/itm/1971-Mercedes-Benz-280SEL-Mechanical-Bosch-Fuel-Injection-Pump-R24Y/172934824820?hash=item2843b80374:g:DdwAAOSwHHFY9~kf&vxp=mtr

I am curious as to why you need another pump?  What is the issue with the current one?

[Taleb]

Thanks Tyler

[Taleb]

Thanks shvegel