New nozzles= runs real bad. Lots of white smoke, heavy nailing. Took the shims out of the two nozzles that had them and it wouldn't even stay running. So I put them back in. Wish I had some shims... Am I missing something? I would put the old ones back in but I didn't mark which was which.

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1981 300D 205,000 mi.

Yes you are missing something, new nozzles MUST be tested and adjusted with a pop tester.

Crap. I guess I read a couple posts where people hadn't and gotten away with it, so I assumed the testing would hit the sweet spot and not end up in a run/no run situation.

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1981 300D 205,000 mi.

and still have a running engine, get very lucky and had very bad injector nozzles to begin with.

They must be popped and balanced. Not doing that in a gasoline motor would be something like semi random sparks at the plugs - some too early, some too late.

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

I replaced my nozzles with 105,000 miles on them with new old stock
Bosch in my 85 TD. I did not pop test. The car runs superbly. No smoke.
Now starts and idles with no throttle input on first start up. Lots of power,
23mpg in town. You can in fact get away with no pop test.

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85 300TD FED-Daily
84 300SD-Wife's
86 XJS-Sunday
66 GMC-Work- Given to my stepson
83 BMW Airhead- Given to my stepson

I also got away with no pop test, but I already knew my injectors were balanced before the nozzle swap and each one of them had a shim and I didn't swap any parts between injectors. In your case, you do need pop testing since your shims seem to be in complete disarray.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Like me and others have said many times, don't wast your time doing this. You need to pop and spray test them when you yank injectors apart.

Take them out and bring them to your local diesel injection shop.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

That depends on the quality of your local diesel injection shop. The one nearest me says up to 14 bar difference is OK. Besides new nozzles need time to break in before they settle in with a specific pop pressure. From my own experience, doing nothing but swapping the nozzles themselves should not alter the pop pressure drastically.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

These cars idled so nicely when new because they all received a matched set of inj's at the factory.

On the inj assembly line for example, all 135bar inj were put into bin #1, all 138bar in bin #4 etc.

Balancing to within a few bar is always preferable.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Absolutely. Before my nozzle swap all my injectors were within 2 bar of each other. I don't know what they are now, but the engine still idles the same. Smooth as butter.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

You can but you should NOT try to do it.

I was having nailing problems with my fathers 300dt, so decided to build a pop tester and clean/test for pressure and spray pattern. They were all low ~115bar and differed by as much as 15 bar.

When I went to balance them I could no believe how little was needed to make a huge difference in pop pressure and spray pattern. I can't imagine how much the injectors could be off just from manufacturing tolerances with the new nozzles.

I would always test and set injectors if I was doing anything to them, but then again one could get lucky and have them be smack on without changing anything but the nozzle.

C Sean Watts, I know you deal with a fare amount of nozzles, is there much difference between the different nozzles height wise? Especially from different manufacturers.

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1998 Mercedes E300TD

1983 Mercedes 240D Turbo, 131bar injectors, Cosworth intercooler and 63' Ford Falcon radiator, Ardic Parking heater, Headlight wipers, Best 38.6mpg.

1973 Saab 96 Rally Car, 1.8l V4 with all the race bits

There should not be much, if any, variance but pop pressure is not from the nozzle height variance.

The "S" in the part number DN 0 SD 2XX describes the size dimensions. More or less, a cylinder with a flat bottom. The others, I have seen in a book somewhere but I can't recall just now.

The pop pressure varies when the factory machines out the body and needle together. They are mated to one another and must be kept together. No, NO two sets (nozzle body and needle) are the same. When the nozzle is put into the injector, the spring puts pressure on the needle to keep in seated in the body. At the seat point(s) angle, depth, smoothness of mating surfaces, all come into play with how well the nozzle seals. *hint* they seal at a metal to metal contact point. Lack of proper sealing = drips, leaks and poor sprays. The shape of the hole and how the pintle fits through it control the shape and pattern of the fuel spray cone. These tolerances are within less than thousandths of a millimeter (0.001mm) Remember, metal to metal contact points will always abrade over time, some slower, some faster. The springs are made with known spring rates and will get the pop pressure to within a min. and max. window but far off from where the engine needs them to be. Remember, changes in pressure = changes in timing. The shims come into play then. They are used to increase or decrease preload on the spring thus, raising or lowering pop pressure.

Difference from different manufacturers -- IF the machinery used, CNC (and in some cases analog) to make these parts is not as good as possibly can be the result will be parts that will not be as good, either. In other words, margin or error is greater, more tool chatter, heating and distortion of the cutting surface, wobble on the machine, the list goes on. Also consider BOTH method of manufacture and stock metal going into the parts. To a point, the machine is only as good as its operator. I can't speak for too many other places but I do know my brother in law went to machinist school in Germany for nearly four years before he was eligible to test for his "meisterbrief" or master certificate.

What it comes down to is the differences in the machined surfaces that we're talking about are so small they really can't be seen with the naked eye.

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

That is within the factory range of +/- 3 bar.

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

Was the car even able to start? I've seen 8 bar off in a VW 1.6 liter prevent it from running. All it did was smoke like a mosquito truck.

NOT trying to hijack the thread but answering one at a time makes it look that way.

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!