Analyzing crank position sensor and cam position sensor capture.

Guys, can someone here comment on my capture?

I have included a screenshot and have several questions regarding what I have found.

This is for a Volvo B6304T (Inline 6, Turbo). The crank signal is variable reluctance obviously. I see 60-2.

The intake cam signal is a hall effect and seems to trigger twice each 720*. Would either of the pulses indicate the duration of the valve lift? If so, that would be the first window and not the second window that I have marked on the waveform, correct?

This is a monolithic engine and therefore, I am not sure how I can easily find the first TDC angle. I am hoping that it can be done analytically with the capture.

Also, I have wired this to an EMU Pro 8.

Thanks for your time in advance,

Greg

Since you have access to an oscilloscope, my suggestion is to fit a pressure sensor into cylinder 1, and remove all other spark plugs. Then you will be able to tell approximately when TDC of cylinder 1 is relative to your crank sensor gap. Your CAM trigger will end up being fixed offset, and you will likely need to choose a low numbered tooth crank to sample the cam sensor and determine which phase of the engine is active. Not sure how you set that up in the EMU Pro 8 -- hopefully the documentation will help you, or you can send that new scope capture to ECU Master for their expertise.

Good Luck!

David,

Thank you so much! I went straight out and built a pressure transducer. It isn't the best because I don't really have the right adapters (so it leaks a bit under compression). But I did manage to get a definite pressure spike indicating TDC on #1.

I am going to go get the Hantek and hook it up now and see if I can get a full Intake/Exhaust/Crank and TDC read from the hardware.