valvetronic Motors-Steppers Or? How to Test

[cfoss]

Aha, good comment.

One test I did was to disconnect the motors and position sensors, then crank the motors all the way to valve open using the 4mm allen key.

This is supposed to make the engine run, while controlling the airflow with the throttle body.

It did run, more smoothly at first, then the miss came back. In general it did not run very well.

This would tend to indicate that the valvetronic is not at fault, as you have suggested. I'm just trying to do a process of elimination to get to the root of the issue.

A couple of other things I noted. I reset the valve lift to minimum on both banks, then reconnected the sensors.

I connected a 12V test light to the drivers side bank, and turned the ignition to run. I had read that the motor should try to go to full open then closed to learn the range each time the engine is started. That didn't happen. The light did not illuminate at all. However, when I crank the engine, the light came on indicating some movement was being called for.

It seems there is a lot of misinformation out there on this system, or perhaps info that pertains to one version or other but not all of them.


The spark plugs look fine-haven't tested them yet. It would be very strange for them to work, then not work, then work again. I will check them soon.

I figure I'll do my best to check the lift system, then start moving forward.

While I have the valve cover off I'm going to rechech the cam allignment, although one would have to guess that would affect the whole bank as well.

I did a leak down test before I started to see if the engine was worth working on. the results were very very good.

I could recheck but It's unlikely anything has changed.


Chay