PD injector malfunctioning

So I got the dreaded 18074 error N240 injector 1 malfunctioning and a misfire code on my PD. Checked for resistance on the big round connector, circuit is open on injector 1 , the others check at 0.3-0.4 ohms.
has anybody tried cleaning up the connector inside the head and fixed the same problem ?
what's the best source to get a replacement injector ?
It started as slight misfire around 2800 rpm during the day and now it acts up all the time , even at idle

Try pulling the valve cover and checking for a loose connection at the injector. I recall folks in Europe having this problem.

All of our European friends seem to end up replacing the head wiring harness. You could probably repair it by crimping new connector terminals on the injector connections. The injector itself is probably OK.

Good luck.

If the connectors seems ok, the definitive test would be to swap injectors around. It would be a PITA, but it's a test to be sure before dropping the jingle on a new injector.

That's what I am hoping for but with my luck , it's probably a fried solenoid in the injector. I will pull the valve cover this weekend and check the wiring/connectors, any particular way to disconnect the wires from the injector ? just pull them ?
everytime i was checking the cam/lifters , i was always fascinated how those wires can take the extreme temps and oil and not break down

whitedog said:

If the connectors seems ok, the definitive test would be to swap injectors around. It would be a PITA, but it's a test to be sure before dropping the jingle on a new injector.

Click to expand...

why ? can't resistance be measured once the connector is pulled from the injector ?

Dimitri16V said:

why ? can't resistance be measured once the connector is pulled from the injector ?

Click to expand...

Well, yeah. If the resistance is fine, then assume the the harness is the problem. If either manipulating the connections or replaceing the harness doesn't fix the problem, then I would swap injectors, but I'm the kinda guy that likes to be exrta sure when electronics are involved.

It seems to me that the connectors don't simply pull off, but there is a trick to it involving a pick to release a lock. I could be wrong on that, so take a close look.

Dimitri16V said:

I will pull the valve cover this weekend and check the wiring/connectors, any particular way to disconnect the wires from the injector ? just pull them ?
everytime i was checking the cam/lifters , i was always fascinated how those wires can take the extreme temps and oil and not break down

Click to expand...

When I replaced my injector harness, and later the injectors, I don't recall anything special about getting the plastic plugs off. I used a screw driver to help with the leverage, but I think it was just a tight fit IIRC. Just look closely at them before you pull to hard.

I have the same thoughts about those wires.

"Well, yeah. If the resistance is fine, then assume the the harness is the problem. If either manipulating the connections or replaceing the harness doesn't fix the problem, then I would swap injectors, but I'm the kinda guy that likes to be exrta sure when electronics are involved. "

Before swapping injectors (a REAL pain in the a$$), you can also check the continuity (with a VOM) of the individual wires in the harness from where the electrical connector attaches to the injector and where the harness plug is on the head. If all the wires for the injector that is misfiring show continuity, I would then check for continuity between the connector on the head and the ECU for the wiring to this injector. This is where the Bentley manual wiring diagram comes in handy.

--Nate

well, the car started and idled OK this morning. definitely something gets loose after the engine gets hot.
Nate, it's not the outside harness, the problem is inside the head.
Anybody got the part # for the wire loom ?

038971600
for BEW up to 2006

jcrews said:

038971600
for BEW up to 2006

Click to expand...

thanks. I wonder what is the life expectancy of it ...

I expect mine to last forever.

Some information from my PD.

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i took the valve cover off, checked the injector , 0.3 ohms. squeezed the metal prongs to make them tighter and put the connector back on. the wire loom continuity checks OK. Started the car and it runs smoother.
I recall having it smoke under WOT few months back and running slightly rough occasionaly. Also, some mornings the engine idle sounded like it had a humming , an oscillation of some sort, it looked like a sine wave on the graph. Could it be those were indications of a flaky connection?
if it acts up again I am changing the wire loom.

BTW, the cam lobes and lifters look great

Dan; You are a good man. Thanks for all the data you provide.

Dmitri, so did that completely fix your misfire/stumble?

yes , it did. I think it's a good procedure to pull connectors out and clean contacts on injectors and also squeeze the clips on the harness cables to make better contact if the valve cover is pulled .

Had two trouble codes:
18074 - PD Unit Injector; Cylinder 1 (N240): Electrical Malfunction
16685 - Cylinder 1: Misfire Detected
Cleaning the pins on the fuel injector connector with contact cleaner and carefully slightly bending the contacts worked for me
This forum is a God send. Thanks to all who share thier TDI maintenance experiences!
Don R.