Most of us would not like to pay a shop to rebuild an injection pump either. The vast majority of these cars are not in the salvage yards because of failed injection pumps as well..

Anyways always prove the injection pump it is good or bad first. Buying things that are not proven bad is no fun. The tests I suggested would do this.What we feel as individuals is not the issue really.

The true issue is rooting out whatever the real problem is and dealing with it. Mr.Hunter is probably right in that you may also have to repair any self inflicted disturbance to the alda area.

Or a chance on a cheap used injection pump is in order if it is proven the problem. The pick and pulls in your area may even have return policies if the 50-100.00 dollar replacement is bad as well. Hope you have some salvage yards in your area with old mercedes cars. I no longer have any.

Always remove any replacement injection pump from the engine. If already off the engine it may have been sitting around dry with no fuel in it for a very long time. That is adding a real risk.

If I want to store a good used injection pump I usually immerse it in diesel fuel in a can and seal it.

A little while ago having to flush the pump with a chemical to get the two injectors or elements activated was not good. It indicates a lot of something was getting into the system where it is not supposed to be. There may still be some junk present in there.

It is both not practical and virtually impossible to do major injection pump reconditioning at home. Besides the knowledge and parts you would need very special equipment. In addition it is a piece of real precision equipment..

It always amazes me how long these in line injection pumps can last with good care. By the same token they can be ruined very fast.

I have thought of an even easier test if you are waiting for the lift pump kit to arrive. Elevate a diesel fuel supply well above the car with really clean diesel fuel in it. Feed a hose directly to the injection pump.Bleed your new fuel supply by loosening the return valve until fuel comes out. If the engine will not run with this setup in my mind the injection pump goes if you want to burn straight diesel fuel.

If you are content to run the 50/50 mix then just repair the alda area. I would also run a solvent into the injection pump and let it soak as well. A lot of mess in there could still be present. Causing some additional problems.

Once again I usually never suspect the injection pump early in the game. Some of your symptoms just seem to make it a good possibility this time around. Anyways keep at it. It can be a real learning experience.