Testing fuel injectors

Hi.

unten hab ich gelesen, daß der Ausbau der ESD relativ einfach sein soll. Jetzt möchte ich meine Düsen und Kompression auch mal prüfen.Ein Bekannter hat mir gesagt, man könnte die Düsen evtl. Instandsetzen, das wäre dann billiger als komplett neue. Geht dWhat?
And what should I pay attention to during installation? (Tightening torque, bleeding the lines, etc.)???

Best regards, Claus

The nozzles can be adjusted using washers, but without the appropriate testing equipment, it's not possible to achieve meaningful results. You can also disassemble the nozzles, but this should only be done if there is dirt present. The best approach is to take the removed nozzles to a workshop with testing equipment (and adjustment options) and have them tested there.

TDI injectors cannot be repaired (at least not by a Bosch service center) due to the two different opening pressures. Instead, Bosch centrally reconditions these injectors for replacement parts.
The information about the pre-combustion discs is correct, but there are only a few testing facilities that can check the pre-injection pressure. With diesel engines with pre-chambers, the injectors can be easily repaired (I've done it myself before).

Das Einspritzsystem zu demontieren ist relativ einfach: Leitungen abschrauben, Leckölleitungen abziehen, Düsenhalteklammer abschrauben dann können die Düsen einfach herausgezogen werden. Anzugsmoment ist mir nicht genau bekannt (ich glaube 45N). Bei den Leitungen ist vorsicht angesagt: nicht knicken oder biegen und auch keinesfalls den Haltebüges zwischen den Leitungen demontieren (Bruchgefahr der Leitung)!!! The fuel injector line should be loosened and removed using an open-end wrench (torque: 35 Nm).

"Bleeding the lines is also not a secret. You can either prime it for a long time until it runs (not recommended), or leave the retaining nuts on the injectors open and prime it until fuel starts to leak out of the nozzles, then tighten the retaining nut completely (35 Nm). When starting, listen for any unusual noises; if you hear anything, stop immediately (this happens if dirt has entered the system)."

ATTENTION!!!!!! When dealing with open fuel systems, extreme cleanliness is crucial because even the smallest contaminants can damage the system.

Best regards, Bertil.

Passat TDI, year 1999, engine code AFN, automatic transmission.
Okay, so...
Yesterday, I replaced all the fuel injectors in my wife's Passat (with Bosch replacement parts from my parts supplier) - cost approximately €300. The car has 138,000 km on it - and the effect is dramatic =
It no longer rattles, is much quieter, more responsive, and doesn't even produce any smoke during cold starts or when starting off!
There are a few things to keep in mind, however.
1. Without a puller (a hammer, which I would have to get myself).
I built them myself, but I have no chance of getting them out!
2. Vorher Wärmeschutzdichtungen bei VW besorgen. At the...
Bosch nozzles are not included.
3. Torque specifications - Retaining bracket screws: 20 Nm.
'Over-torque nuts 25nm - only works with...'
Cowboy boot or crow's foot!
4. No issues with bleeding the brakes - the engine started after about 5 seconds!
5. Make sure to obtain the necessary materials for the return/overflow hoses beforehand!
(were completely worn out after 3 years / 138,000 km - just falling apart!)

Otherwise, it was just a walk - it took me about 40 minutes!

Best regards from Jürgen.

Whether injectors can be repaired depends solely on the type of engine they are installed in. Injectors from chamber engines (older BMW, Opel, Mercedes, etc.) can still be tested and adjusted as before (using the mentioned shims). These are then various types of pintle injectors.
The injector nozzles of DI engines are not adjustable and can only be partially tested. Only the sealing, spray pattern, and opening pressure of the first stage can be checked using workshop equipment; nothing else.
Only Mitsubishi plans to repair the nozzles.
Common rail injectors or pump-nozzle injectors are generally not repairable.
Best regards, Lanz.