1.9 AHU, possible needle lift sensor issue!

[ed_the_robot]

Hi all! Long time no posts, I’m a tdi owner nowadays.

I’m trying to troubleshoot an issue.

Does anyone know, for 100% certainty if I have the ignition on and engine off, what voltage should I read when placing a multimeter across the unplugged connector for the needle lift sensor, on the loom side? I am seeing 11.3 volts, from research I should be seeing 3.2 to 5 volts.

Sensor resistance itself reads good.

I am trying to troubleshoot code 00550 start of injection, control difference which I believe is pegging the injection pump to full advance.

I do not suspect the timing has slipped as the issue was intermittent at first. In any case my next point of call would be to check static timing but before I start doing that this voltage at the needle lift sensor is bugging me.

Any ideas?

Ed.

[davidoft1]

There’s an advance solenoid in the fuel
Pump, check it’s operating, I would suspect this over the needle lift sensor