IP and Injector Differences

[Fisherman]

I have a 80 300D that is still having problems with a slight miss in what seems to be #2 hole.
Compression numbers look good but no matter what I try it doesn't seem to fix it.

I am now thinking it is the pump. I have access to a couple of pumps.
1 is off a 79 300D and the other is off an 85 300 Turbo.

What is the difference between a turbo and non-turbo pump and the injectors for these cars?

Physically the appearance of the 85 pump is a match as I believe it is a MW pump like mine. The 79 appears to have a M-RSF pump.

Could i use either of these as a test for my pump?
Could I exchange these injectors for testing also?

Thanks

[h2odiesel]

First swap injectors from your "bad" cylinder to another to see if the problem follows the injector. If it stays with the cylinder try swaping the delivery valve bits. Remember to keep things very clean.

[Fisherman]

so what you are saying is that the internal parts can be swapped? By delivery valve do you mean the piston, valve and spring?

As for tracking the cylinder it is really, really tough to say that I absolutely know which one it is. I think it is number 2 and as I have swapped the injector here twice I think I'm closer.

the interesting thing is that it seems to run a little better when I swap out tjhe injector but after a day of running it the proble seems to worsen again to it's old condition....

Is it possible that my valve guides in this cylinder are leaking and causing the injectors to foul?
I just drove 550 miles yesterday and used a quart of oil yet this motor's compression test was good in all holes with minimal variance between them.

I'm not smoking a lick except on startup and some noticeable amounts at idle but always assumed this was basically normal for these motors.