I would like to show and get some feedback on the spray pattern I got after injector rebuild.
I have removed the injectors from my 85 300SD with 190k miles, I believe the injector nozzles were original (Bosch240). Testing showed high internal leak down, so I decided to rebuild them. Dissembled, lapped, cleaned, and reassembled with new monark 261 nozzles. All popped around 1950-1975 psi, internal leakage is good now, but I'm disappointed with the new nozzle spray pattern.

inj1 - heavy center droplets, not good, maybe acceptable
inj2- looks good
inj3 - asymmetrical, heavy droplet sideways, not acceptable
inj4 - looks good
inj5 - heavy droplets at the center, side spray, not acceptable

i have retested and captured the random sample of old 240 nozzle. Much narrower spray pattern, but good atomization and droplet distribution.

Questions
- Am I looking and evaluating the spray pattern correctly?
- What should I do with nozzle 1/3/5? Disassemble clean and retest? Send them back?
- Run them in the engine a bit then reevaluate?
- Any other suggestion?

Attached Thumbnails

   

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1985 300SD - very special CA edition

What should I do with nozzle 1/3/5? Disassemble clean and retest.

This.

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

Something isn’t right… so opening them up is the first thing to do.

Did you test any with OE original nozzles before taking them apart?

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
2008 ML320 CDI (199k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

yes I did tested all of them. Spray pattern was good, opening pressure was good, but all had high internal leak down.

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1985 300SD - very special CA edition

If they pop good and crisp, without any "peeing" before they actually pop, I wouldn't worry about that difference in pattern. I've built several hundred injectors for W123's and not had any bad performance attributes from slight differences in spray pattern as long as the "pop" is crisp and quick, with zero fuel coming out beforehand.

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'82 300CD
"Pearl", the very first turbo diesel 123 coupe
Totaled 11/23/18, rebuild in progress.
'85 300TD, "Artemis".
'78 300D euro, "Ol' Red", mostly retired.
'85 300D, "Gandalf".

thanks for your input - I will retest it over the weekend.

I recall the opening was prompt, but depending on how I operated the handle therefore how fast the pressure ramped up to opening pressure, I could get some fuel leaking out, wetting the nozzle, but no spray. I think that is just the way I increased the pressure, slowed done close to the expected opening pressure. I will no more testing.

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1985 300SD - very special CA edition

I'd return them, they'd all suspect .

The spray patterns must be identical ~ you can easily see his is not so, therefore they're suspect .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

The nozzles should have the potential to stay basically perfectly dry before the pop - fuel seeping out as pressure gets above, maybe 1500 PSI? isn't supposed to happen. Unfortunately I've seen this on a lot of Monarks the last ~5 years, caused by a chronic defect on the pintle that varies in severity and hence is sometimes a problem from the start, sometimes shows up after running for a while, sometimes never does.

yes, the nozzle should not leak fuel at lower then pop pressure. I will test in at 1500psi or more, and see if any fuel leaks out.

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1985 300SD - very special CA edition