Will a 1983 240D injector pump bolt onto a 1976
 

First, is it interchangeable, and second, if it is not will it at least bolt up and work so I can test a motor: I can get a 1983 pump for cheap and would like to use it to aid in diagnosing the no start problem on my 1976. Thanks.

Just a little help here
 

Hey Buddy, now don't jump off into the deep end man. I have been messing with diesels for years and can do a lot of things, but messing with the IP is not one of them. You have an earlier post with some very good suggestions that you should follow up. I would say that your problem solution most probably has been given and that your diesel is sucking air. Find the problem. IP's just don't go south while the car is sitting for a day or two in the car port. That just doesn't happen.

Not interchangable anyway.

Junqueyardjim, you are probably right about it not being the pump, but wrong about the solution being amongst the post's responses. I have tried everything suggested and have determined while checking those possibilities, that the engine had little or no oil in it. Another person here just suggested that the engine (compression) died during the last drive, due to the lack of oil. I am beginning to think likewise because WD40 in the intake did not cause it to fire. I can say that after I put the oil in, as I cranked the engine and watched the oil pressure gauge climb, the cranking got slower, indicting an increase in compression/resistance. If that is the case, the compression increase is apparently not sufficient to aid in starting.

Usually that is the result
 

Run any engine without or very little oil and you are knee deep in du-du. Mercedes diesel I think are right at the top of the pile when it comes to being intolerant about running with very low oil. They just don't like it at all. If the car is decent, I would look for a good used engine. Remember, if you want it to run again, don't touch the IP, ever.

Check the compression before you declare the engine dead

I have ordered a compression gauge, but I believe this engine now has little or no compression. If the compression is low I heard that a hot engine will help an engine with low compression start. As my final test I will hook up a auxilary starter wire about 50 feet long, take out the tank so it is only running from what is in the fuel filter, put it in the middle of my remote acreage, then start the car on fire, then engage the starter. If it kicks before it is totally condumed by the fire, I will have determined what the problem is and will have the added benefit of knowing that I cannot fix it so will not have to waste anymore time.

In all seriousness, if I look at my hourly wage, if I had been working instead of messing around with this car, I would have made what I paid for the car. I have the kind of personality that I hate to give up and so I will get mad, quit for the night, then get up the next morning and continue to waste hours upon hours, on lost causes, or car that don't have any significant value. I don't often fail at fixing whatever I am working on, but many times the result is that I spent a lot of time on thing that have little value when I consider the time invested. I remember putting an engine in a older car. When it started there was a noise from the flywheel hitting the converter cover. I asked an assistant to spin the engine so I could see where it was hitting. He turned the engine with a wrench on the cam gear and ripped the teeth off of the new timing belt (the reason the engine had to come out in the first place. I picked up a 3 foot pry bar and asked him if I should: He knew what I meant, but didn't say anything. I said yes myself and proceeded to break out all the glass and dent every panel. He thought I was crazy but I told him I did the right thing because I made it impossible to fix so I would not come back out tomorrow and waste anymore time. There was a method to my madness and I know after years it was the right move because the time I would have wasted on that car was spent way more productively. I am at the same place with this 240D.

The value was in the way it ran and the cleanliness of the interior and the fact that it was a diesel. I paid $1000 for it running and I cannot see spending $1000? for an engine to put in a $1000 car, nor can I see the sense in rebuilding an engine in a $1000 car. I don't know if this has any value for parts, if not it is going to the scraper. I can get a couple hundred of my cost back at least.