injection pump

[north clark]

Hi, Anybody out there familiar with the cylinder inserts with fuel inlet port holes, it has a grooved out portion below the larger hole like it's supposed to lock into certain position but don't see or feel anything like it inside the pump housing, I would think it should go in oneway because of the grooved plunger to work properly.
Will appreciate any help I can get and I thank you in advance, injection pump out of 72 280se.

richard k

[Shvegel]

If you removed the cylinder from the the pump or even turned it in the rack you will need a fuel injection flow bench to get it back in the proper place. The fuel delivery for each cylinder is controlled by rotating the cylinder relative to the others.

[north clark]

Hi; thanks for the input but I had no choice but to take the inserts out because the rack was seized up badly and when trying to free the rack the inserts probably turned out of position, I never had a rack seized this bad before.
richard k

[Shvegel]

Pretty much any diesel injection shop can handle it. They put it on the bench and bleed the air out. Then they run the pump at a specified RPM for a number of revolutions then see how many cc's of fuel were delivered at each injector compared to the spec. Any differences are compensated by turning the cylinders relative to each other.

[ja17]

Hello Richard,

There is a pin which locates the groove on the outside of the IP cylinder.  Just removing the cylinder will not throw off the calibration of the injection pump since the plunger is what is actually rotated by the rack.  Just line up the IP cylinder with the pin and slide in in place. You should see the indexing pin inside the pump.  If the pin has beed accidentally pushed back you may have to remove the side access cover of the IP and tap the pin back into the opening in the pump.

[north clark]

Hi Joe;
I knew I'll get a response from you and you would know what I was referring to, don't know why I didn't think of it or look for it myself I guess I've been retired too long already,  anyway you are right about the pins but kinda strange its not doing its job  all the pins are not sticking out past the opening and I can't think all the pins got sheared off or backed off, anyway I'll it put back in position with the pins and see how it goes.
Thanks Joe.

richard k

[Shvegel]

Joe,
I stand corrected. It's been 5 years since I had mine apart. I have a spare in the basement and I am going to pull the side to take a look.

Regards,
Pat

[Benz Dr.]

I can't add anything to this except that most diesel injection shops won't even look at  gasoline injection pumps. Kind of like chalk and cheese I'm told.