Section 3-15 Fuel injector misfire case study

In the video in Section 3-15 (30), Fuel injector misfire case study, Ford Taurus cam sensor problems, I was just wondering why you set the cam on the 9th tooth of the crank signal. Isn't that like 90 degrees?

Hey joshbierman! It's counterintuitive, but aligning the cam pulse with the 9th crank is correct on this engine. It makes logical sense to align the crank sync notch with the cam pulse, but this is rarely how manufacturers align their cam and crank signals. Why? Who knows. :lol:

It also makes logical sense to figure that the sync notch is TDC #1, but that usually isn't true, either. :silly:

As an example, this is a known good capture off an '06 Kia Spectra. Again, no clear reason why the OE chose this cam/crank relationship, but it's correct:

Thanks, One more thing. How did you find that information? Just check it on a know good one, or is it out there somewhere?

Kinda depends on the manufacturer, and the service information they provide. Some makes, like Toyota, Kia/Hyundai and Chrysler will provide known good relationships, which make their way into services like Mitchell and AllData.

Others, like Ford, don't show that relationship anywhere. :lol: In those cases, it's all down to guys looking at known good vehicles and providing the waveforms to others. This is why places like iATN and Pico's waveform library are so valuable.