Weird Cranking Osclloscope Results.

[gnutz2]

I'm running my i5 audi engine wasted spark with a single VR crank sensor. I have 15 pins on the flywheel with one missing.

The other day I used the crank oscilloscope for the first time and these are the results.



The green are a single missing tooth and blue are two so as you can see every other missing tooth is seen as 2 teeth. This is obviously not right.

So, I swapped the VR wires round and I got a good result, every missing tooth is seen correctly.



Problem is the car runs fine with the wires in the position the ECU says is wrong, but it usually takes a few turns of the engine to start. When I swapped the wires the car started better but wouldn't idle, I assumed this was because I use ignition for idle and the timing would be different now, I strobed the timing back to zero, it was about 25 deg out, and it still ran like crap.

For now I'm running the sensor in the wrong position because it works better.

Would the double gap alter my timing? I assume it would.

[stevieturbo]

If the sensor is wired wrong, it will affect ignition timing as you will be triggering off the wrong edge

Really this is where a proper oscilloscope is really needed to ensure you have it correct, DTA's own scope is poor as it just doesnt offer enough info.

If you can verify timing at various rpm's and various timing numbers are all correct as displayed in screen and with a timing light, then you should be ok.

[gnutz2]

I thought an oscilloscope would be wise route.

But the car runs good with the sensor in this position so that probably answers my question.

[stevieturbo]

If you can verify timing is as you are asking on screen, then it's probably fine.

But I would absolutely check it.