What about the air that might be trapped between the banjo bolt and the injectors? If you tighten the banjo bolt while fuel is seeping out from the tank pressure, would you not eventually see fuel coming out of the injectors as well?

I thought that might be the case but I waited quite a while and if the fuel traveled at the same speed as it did to get to the banjo bolt It would have come out of the injectors long ago. But nothing.

Does the injection pump have to be cranking in order for fuel to get to the injectors or could pressure ffrom the fuel tank do it?

I'm no expert on the injection pump, but I believe that with the method I described, no fuel would come out of the injection pump, unless the engine was being turned by the starter. It sounds to me that you have an air leak somewhere in your Greasecar system. From looking at the Greasecar web site it seems to be a common problem. I would suggest checking all of your clamps on the Greasecar valves. Isn't there also a problem if you loop your return line and returning it before or after the filter, something about getting air trapped in, and not being able to get it out. You might get some help on Greasecar.com Dave

Its unlikely its the greasecar system because theres only one GC valve that the diesel passes through before returning to its normal course and Ive checked that valve and both the hose and the valve are very new and there doesnt appear to be a problem in that area, unless its very difficult to see.

I did use the method of pressurizing the tank. I did it through the return line as it was the only option. I was just hoping for annother entry other than the return valve as it made such a mess and is difficult to get at.

I guess Ill keep trying and see if I get it a 3rd time. 3s a lucku number eh?

So After trying everything to no avail I brought it to a mechanic who finally determined the new primer pump was causing the problem but they didnt know why.

On two different occasions they put the old one back on and it started right up. I still feel like there is power loss due to air entering the primer pump, But I see no other option that to try and make it work with the new one.

I went to a MB dealership here and they showed me a diagram of the primer assembly and a picture of the original pump and they said they would could order it and they did. I went to pick it up and it was the same BOSCH primer pump that Ive been trying (except with a price tag twice as high) Thankfully they let me return it.

Any Ideas? Can you get the old screw off primer pumps new anywhere? or are we stuck with the newer BOSCH ones.?

do you see the difference in these 2 'updated' primers... is it possible that you tried the one that was NOT intended for your engine?

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Very Interesting. I have the one on the right, the 126. That is what was sent to me and really the only option I had to choose to order. How would i know which is made for the car otherwise? Its such a simple piece of equipment it seems there can be little to go wrong with it.

I almost 100% sure that is the one you want. They are each rated for different lift pump pressures.

Did you replace the copper washer beneath it when you installed the new primer... its hard to tell its even there.

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Yup, replaced the copper washer, and so did the mechanics when they did it. so i know its not an installation problem. Interrestingly enough, when I do a search on bimmerspecialist.com or.ca for the pump assembly or the base to which the small pump screws onto for my year and model of car, this is the picture that they show.
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Its the same as the one on the left (125) in the picture you posted of the two comparing. However every other source Ive contacted say its the other pump I need (126) Is there a big difference in the pump assembly (the base to which the hand pump screw into?)

I guess I dont know how to post a picture. any tips on that too?
Thanks
Michael

You can search on Ebay and also other Parts sellers on the internet. Both the older and newer style primer pumps are still on sale; with the older style selling for a few dollars less than the newer style.

There was a member who over 1 year ago had problems with the newer style primer pump. He exchanged it for another from the same place and still had a problem. He returned that one; got his money back and went to a store in a different location and bought another newer styly primer pump.
The last pump worked. He concluded that the 1st store he went to must have gotten a bad lot of primer pumps from the maker. By going to another store he got a new hand primer from a different lot.

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84 300D, 82 Volvo 244Gl Diesel

No matter how you bleed the fuel supply section of the IP the delivery valve springs have enought tension on them that it would keep you from bleeding them all they way up to the Injectors; with the hard line nuts up by the injectors loose.

It might be possible to pump with the hand primer and overcome the spring pressure of the delivery valves if you wired the manual shutoff lever down and blocked of the fuel going out of the overflow valve.
This might allow you to pump fuel passed the delivery valves up to the loosend injector hard line nuts.

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84 300D, 82 Volvo 244Gl Diesel

I guess you wouldnt happen to know how to find this person would you? It would be good to get more info about what happened and see if his situation was similar. Of course searching back a year isnt exactly easy or even possible. Just a shot.

Did I read correctly that you have bubbles? If your getting air out in bubbles then your getting air in. This is the first thing you need to trouble shoot. Try replacing a section of hose with clear pvc so you can SEE whether fuel/bubbles are present.

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For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

Ya the bubble problem was solved. I had a wrong size primary pump and even though it felt tight I guess it was cripmping the line enough to let air in. I may put some transparent line on just to make sure though. Thanks for the suggestion.
Now im almost sure the air is coming from the pump.

I do not remember who posted.
It is easy to search back several years the problem would be if you searched for "Primer Pump" or "Hand Primer" you would get a lot of threads and post that you would have to read through before you found what you wanted.
Sometimes it is better to pick a key word that is more specific to the post like the work "returned". It would still generate a of threads and posts to search through.
Another way to find who is was would be to start another thread and ask; and hope that that same person is a regular reader of the forum.

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84 300D, 82 Volvo 244Gl Diesel

Hi There, Im just looking for anyone who might also have had problems replacing their hand primer pump (in the models that have them) I have an 85 300TD on and the pump seems to be the source of power loss problems. (air leakage) However I went and bought a new one and when I put it in it wouldnt start at all.

I even had it taken to some pro mechanics and they eventually figured out that by putting back tho old primer pump the car would start again. It was installed properly as I did it and also the mechanics did it on separate occasions. Its pretty simple.

Also if anyone knows off hand the two part number differences between the new and old style pumps I would love to have them so I can refer them to the Mechanics or parts searches.

Thanks