MFI pumpelement trouble

[thomasw]

Hi!

On my W111 220 SEb -60 one of the pumpelement wont rotate easily, the piston goes down by the spring when i rotate the pump axle so it is not totally seized, but the control rod is very hard to move.
Do you think it will loosen up if i soak it with some oil?

Thomas

[ja17]

Yes, soak it with some penetrant and also work the control rod (rack) back and fourth until it frees.

[thomasw]

OK, i have filled it up with some Redline, hope it will help, seems to be more stuck when the piston is at the top position than bottom.

Thanks Ja17!

[Aaron h]

OK, i have filled it up with some Redline, hope it will help, seems to be more stuck when the piston is at the top position than bottom.

Thanks Ja17!

Then that means the plungers are sticking inside of the barrels.  Take the two pipe unions off of the top of the pump, remove the delivery valves, and drip in a mixture of ATF and WD-40.  After your rack is unstuck and the car runs the plungers and barrels will free themselves up just from operating, and the ATF/WD-40 mixture will minimize the wear while the plungers are cleaning the walls of the barrels. 

[thomasw]

Then that means the plungers are sticking inside of the barrels.  Take the two pipe unions off of the top of the pump, remove the delivery valves, and drip in a mixture of ATF and WD-40.  After your rack is unstuck and the car runs the plungers and barrels will free themselves up just from operating, and the ATF/WD-40 mixture will minimize the wear while the plungers are cleaning the walls of the barrels.

Thanks Aaron h!

[Pawel66]

Thomas, just making sure that you looked through this:
https://www.sl113.org/wiki/Fuel/Injection

There is a lot of info that helps understand how it works, what to pay attention to and how to go about it. Also if you search the forum, you will see you are not alone and Members have been through the procedure you are going through now.

[Desertpagoda]

or, if you really want it to free up...use 50/50 atf and acetone and get a brass drift that will fit down the hole and apply
 pressure as you rotate the engine(after you remove the deliver valves of course)