injector spray pattern?

[kevinm]

How important is the spray pattern. I got them rebuilt and was curious as there is black smoke under load going up hill kind of thing. After taking them to someone with a tester we notice two injectors were not making a conical pattern.. Ide say half cone and straight stream..

[Blocksmith]

From what I understand, you don't want any stream at all. Means it's not atomizing. Which brand and type of nozzles are they?

[CrazyAndy]

Block, you're right.  Improper atomization AKA streams create droplets which cause incomplete fuel combustion.  Droplets are one of the main causes of smoke, since the fuel in the center of the droplet doesn't completely burn and turns into carbon particles.  That is what is causing the smoke under load that kevinm is concerned about. 
Kev, you're going to have to get some new injector nozzles for those two bad injectors.  Send them back to the re-builder if you can and list you concerns with them.  Who did the service?  Hopefully they will honor their work and fix them.  Report back with your results;  hopefully this will all be peacefully resolved.

[RabbitJockey]

Also the streams focus all the fuel on one spot and create lots of heat, very bad!

[CrazyAndy]

Also the streams focus all the fuel on one spot and create lots of heat, very bad!

Ah yes, forgot to mention that part; it can cause pitting in the precups and pistons, to say nothing of part failure from heat.

[kevinm]

Found my invoice. Looks like part number 5643822 and after doing a search it looks like a Delphi nozzle.. made in China...

[Blocksmith]

Found my invoice. Looks like part number 5643822 and after doing a search it looks like a Delphi nozzle.. made in China...

That's most likely the problem...    Chinese stuff is veeerrryy hit or miss.
If you have access to a tester, I would source my own nozzles from a known, high quality brand--and sadly, new-manufacture Bosch nozzles are out, as they're now made in India, and I've read about some people having problems with them as well. Afaik, Meyle nozzles are made in the Czech Republic, and should be pretty good. If I can't get my hands on NOS Bosch or the equivalent Zexel (Japan) nozzles, I'll go the Meyle route myself when I rebuild a couple sets I've got lying around. Gotta finish making the pop tester first, though.

[RustyCaddy]

You might consider Monark nozzles from Mercedessource.  The interchange number ends with 261 i think for 1.6l diesel VW's...still need to install a set but the finish of the Monarks is very good (hope that means something).