injection pump stuck
 

Mercedes 300sd 1983.Hello. I am trying to time my injection pump. I have the 4 bolts loosened. But, the injection pump won't budge either way. Is there a safe place to pry? Thanks, goldveg

Did you remove the 4 hard fuel lines between the IP and injectors?


Charlie

hard lines
 

Hard lines are removed. Do the four bolts have to come completely out? I have been putting good deal of force to pry and turn the pump. So far no one has won because nothing has moved and nothing is broke yet.

Any ideas? Thanks….

The Fuel Injection Pump is supposed to be able to rotate if the Nuts and Bolts are losse but if there is rust in the Bolt/Studs or there is no more room to turn the Pump in the slots that could keep it from rotating.

Also the Front of the Fuel Injection Pump is sealed with a Gasket. It could be someone used Gasket Sealant on it and the Fuel Injection Pump is glued in.

And of course corrosion could hold it in place.

Note that it is entirely possible to rotate your Fuel Injection Pump and have it damge the old Gasket.
To change that Gasket the Fuel Injection Pump is supposed to be pulled out.

Another possible is if someone overtightend the Nuts and mushed in the Aluminum against the Studs.

When I had My Fuel Injection Pump off I had a New Mounting Gasket for it as pictured but I decided it was too thing and I used the Factory Gasket as a template to make another out of thicker Gasket Material so that it would resist getting damaged when I rotate the Fuel Injection Pump later on.

The Drive end Male sort of Gear that goes into the Coupling on the Fuel Injection Pump drive is about 1/2 thick. Moving the Fuel Injection Pump backwards about 1/4 inch should not dissconnect it from the Coupling inside.

By four bolts, I assume you mean the three on the front housing, and the one in the rear. If you did not loosen the one in the rear (it is a pain in the "rear"), then there is your problem......Rich