1.9tdi Idle Misfire

Hi all!
So the missus has a B5 Passat, which has a misfire on the third cylinder at idle, it seems to disappear at revs, as it doesn't stutter and shake about as it does on idle.
I've heard talk about the wiring loom for the injectors on these engines, which is an AVF, by the way, not being exactly perfect. I've found rebuild kits for the injectors, while I have rebuilt a bunch of injectors, none of them even resemble the injectors sitting in this engine, so if I were to rebuild it, I'd be moving into unknown territory and potentially ruining the injector, which has the neat price of about £600+ in Norway, so I'm not very interested in buying and replacing it.


So, what's this about the wiring loom, and are there anyone on here that have some kind of tutorial or instructions to rebuilding the injectors on these cars?


I've used Ross Tech's VagCom to read out error codes and reprogram a few things, so I have that available for use if needed.

The injectors on these take more skill and equipment to replace nozzles. Have you done a compression test to make sure that the injector is the cause?

Usually the injector loom will cause a problem at all speeds, not just idle.

It's the connectors at the injector - they get weak with age and heat cycles.

For the injectors themselves, if you suspect the #3, then I would source a used one, as well as the bolts and o-rings and install that.

This thread details a member that replaced their own PD nozzles

http://forums.tdiclub.com/showthread.php?t=451290&highlight=replace+pd+nozzles

Windex said:

It's the connectors at the injector - they get weak with age and heat cycles.
For the injectors themselves, if you suspect the #3, then I would source a used one, as well as the bolts and o-rings and install that.

Click to expand...

Okay, thanks for the info!

VagCom tells me it detects a misfire on the third cylinder, I've saved the error codes list to my diagnostics computer, I can post it if that helps.

Misfire can be caused because:

Compression below spec (mechanical issue)
Fuel (bad injector/nozzle/electrical issue)

If you only have a misfire code, then the injector may not be the fault. The electrical connector (if bad) sets a different code for high resistance, in addition to a possible misfire code set.