Injectors worn out

I am looking at putting new nozzles on my 98 tdi with 235k miles on it. I have been having issues with fueling and lower fuel economy I think my be associated with the injection. Should the car get new injectors as well or will the nozzles likely fix the problems associated with injection?

Back up the Fail Train a bit. What are your symptoms? Is it just poor fuel economy? Hard starting? Smoking? If so, what color and when? Engine run smooth? How is the timing? How is the smooth idle compensation? Good power?

The car has 235k miles, and is now 16+ years old, so for sure your nozzles are a little "less than perfect", but that doesn't necessarily mean they are "worn out".

The nozzles I was planning on swapping anyway, little bit of an upgrade as well as hopefully helping out with the slight power loss and smoke. The car starts fine but smokes white smoke quite a bit on low end acceleration. The power is definitely not what it used to be. I guess the short is I was looking to upgrade the nozzles and was unsure whether the car should have new injectors as well or how that works?

Sounds like bad pump timing....

Was just adjusted, is within spec

Clogged intercooler? Intake?

So many possibilities. yes check symptoms. I did a set for someone who self-diagnosed, turns out a lifter was blown out.

I know there are a ton of possibilities...The question still remains, if I replace the nozzles is there a reason to replace the injectors with them?

not unless they have been sitting with water in them...

Ok thanks. Someone was trying to tell me that the springs in the injectors get worn out and just dont perform well anymore. I was having a tough time believing that.

Well, normally, nozzles get installed into injector bodies and pop-tested, flow matched, etc. I'd never just swap over nozzles and shove them in the old injector bodies and put them back in the engine. Some people have done that, though. I wouldn't, nor would I recommend it.

Plus, since you are really going after an issue here, which is the kernel of your concern, you really should have the injectors TESTED as they are FIRST, to see what condition they are in right now. Our diesel shop (as most of them) will work with you to verify if your concern is indeed something with the injectors (of which, the nozzle is part of) or perhaps something else. And most of these shops will bench test them for free.

You could have other issues, still.

Springs don't just wear out, especially springs like these. They might creep a little bit - which is why they should be re-shimmed by a diesel shop. In addition to that, all of the other pieces of the puzzle change the pressures at which they pop.

I'm with OH on this, you need to do proper diagnosis.

The plan was to buy the nozzles and have a diesel shop here in town install them and pop test them all.

modder man said:

The plan was to buy the nozzles and have a diesel shop here in town install them and pop test them all.

Click to expand...

OK, that's fine and all, however I would just ask them to check them BEFORE they take them apart, and tell them your symptoms.