Trigger issues haktech platinum 1000 and 36-2 + 1 home

Hi as the title says I'm running a Haltech platinum ecu on a 4 cylinder engine using a 36-2 teeth wheel on the crank and a 1 tooth triggerwheel on the cam.

I recently changed my 12 tooth trigger wheel for a 36-2 wheel and cannot get the car to run right.

This is my first time running a missing tooth trigger wheel and I'm having problems with the engine not running right. Ignition angle mostly where it should be, but sporadically jumps around.

When I'm looking at the "triggers since last home" counter in the ECU, it alternates between 33 and 69 triggers since last home.

I was expecting to see 68 triggers since last home, but are not sure if this is correct as it is my first time running a missing tooth wheel.

For more context here are the specs

ECU is Haltech platinum 1000

Engine is 4cyl 3SGTE

Home trigger wheel is a 1 tooth wheel, basically a circle with a slot cut into it (have been running this exact wheel for years without problems)

Trigger on crank is a standard OEM Toyota 36 - 2 wheel located on the timing belt gear.

Sensor type for both home and trigger is hall sensors (also used theese with the same ecu sucsessfully in the past)

So I guess what I'm asking is what would the trigger vallue since last home be? In my mind it is 36-2 =34 teeth x2 = 68 triggers since last home, but i'm not able to get this vallue. only alternates between 33 and 69 for some reason.

Any tips that could help me out is very much appreciated.

I will include pictures of the trigger wheels to avoid confusion.

Thanks

That trigger wheel is designed for a Variable Reluctance (VR) sensor (also referred to as a Magnetic-type). And I think you would have to have the polarity correct. If your crank sensor is a Hall Effect type sensor, then I would consider machining / filling down the gap so the two teeth at each end of the gap are full depth.

You may need to use a two-channel oscilloscope to look at both signals, so you can verify the teeth are detected and thus what the tooth counts should be. You probably want to make sure the cam signal edge does not line up with a crank tooth edge (some ECUs are sensitive to this -- usually noted in their help/manuals.

Thank you so much. That is an interesting idea that you got there, I wonder how it woukd react if the two missing teeth actually were missing.

If I understand you correctly, you meant just that right? to file down the two missing teeth to full depth right?

I did at first try with a VR sensor as that is what Toyota used with this trigger wheel from factory, but I had the same result. So I switched to a hall sensor as that is what I used in the past but to no avail.

Also how can you tell that this trigger wheel is for VR sensors? Just curious.

If I dont get anywhere I will buy myself an osiloscope just to have a look at the signals.

When it comes to the triggers since last home vallue, what sort of vallue would you expect to see from this setup? 68 triggers per home right?

The VR sensors have a rapidly changing edge and a slower changing edge depending on polarity. The gaps with flat space ensure there is no rapidly changing edge in the gap. Hall sensors on the other hand tend to measure each edge of the trigger teeth equally so a wheel will normally have squared off full depth teeth.

If you tried a VR sensor but it didn't work, first I would make sure the sensor type in the software was configured correctly (no pullup, trigger voltage, correct rising/falling edge). I would also try swapping the polarity of the sensor, and trigger edges. There should be a combination that works. VR sensors also change their amplitude with speed, and sometimes have a table of voltages vs. RPM required (a Hystersis or Arming voltage). You might see .1-.2 volts at cranking RPM, but 5-10 volts at 5000 RPM. So if it isn't triggering at cranking, try lowering the voltages. I don't have the older Haltech software installed to tell you the exact parameter and table names.

BTW - If you think of the triggers as the gaps, there are only 33 gaps on that wheel, so perhaps you should try configuring it as 36-3 if that's an option.