VVT ideas and testers

[jsmcortina]

You have no cam signal.

James

[WORKS]

We're getting a cam signal at Pin 32

[jsmcortina]

We're getting a cam signal at Pin 32

The composite log shows that it isn't making it to the processor.

I think I see why. Although you have configured "dual wheel" your fuel and ignition settings do not need the cam input, so the code is likely ignoring it. I think at least.
EDIT: scrub that.

I've tested again on the stim with your MSQ. I see a cam signal in the composite log. So the problem is that your cam signal is not reaching the processor.

James

[FatKao]

I'm having a problem getting my VVT going. The motor is from a 2005 Mazda Miata with stock sensors. The issue is that the VVT angle bounces back and forth between ~295* and ~270* when at idle. I'm pretty sure the cam isn't moving 20* since the car idles and runs perfectly. The angle change also persists if I unplug the cam solenoid. If I set the duty cycle to 100 the cam does advance and it can be noticed on the log. At the end you can see I advance the cam to full and stall the motor.

At a bit of a loss as to what the issue could be. Since this log and MSQ were taken I have upgraded my MS3 to 1.1 Alpha 18 and the issue is unchanged.



edit:

One thing I did notice is that y8s is using falling edge cam/crank triggers and I'm set up on rising edge. Should that cause an issue? I can't get the car to start if I use falling edge.

[jsmcortina]

Pleas record composite logs of the engine idling.

James

[FatKao]

Attached.

At the very end of the log I advanced the cam, it should be the last two revolutions since pretty much any advance stalls the motor at idle.

[jsmcortina]

Might be best to start a new topic with your engine type in the title, I know that this engine was one of the first to use the VVT code.

James

[FatKao]

Will do. Should it be in this forum or the General Support forum?

[jsmcortina]

MS3 dev

[WORKS]

We're getting a cam signal at Pin 32

The composite log shows that it isn't making it to the processor.

I think I see why. Although you have configured "dual wheel" your fuel and ignition settings do not need the cam input, so the code is likely ignoring it. I think at least.
EDIT: scrub that.

I've tested again on the stim with your MSQ. I see a cam signal in the composite log. So the problem is that your cam signal is not reaching the processor.

James

Using a lab scope, we're getting a nice square wave pattern at Pin 32 where the low side is .8125V and the high side is 4.938V. Are these voltages acceptable for the software before we go tearing into the hardware (Pin 32 to Processor)?
Does the low side seem to be a little high?

[jsmcortina]

You need to be sure that the pots on the MS3X card are set correctly to match the 0-5V hall input.

James

[WORKS]

You need to be sure that the pots on the MS3X card are set correctly to match the 0-5V hall input.

James

I see this:
"When using hall or optical sensors inputs, the cam input adjustment potentiometers should be set as follows. Turn both pots (R11 and R32) full anti-clockwise - approx five turns. Then turn the top one (R11) two turns clockwise."

Which pot is the Low and which is the High and how many turns equates to what voltage?

[jsmcortina]

I don't understand your question.

Did you follow the instructions?

James

[WORKS]

I don't understand your question.

Did you follow the instructions?

James

Yes the instructions were followed exactly. But since the low side voltage is .8125V (which seems rather high), would adjusting one of these pots help the ECU see the cam input signal properly?

[jsmcortina]

Yes the instructions were followed exactly. But since the low side voltage is .8125V (which seems rather high), would adjusting one of these pots help the ECU see the cam input signal properly?

It might do yes. You might need to turn R11 some more clockwise.
If you wish to measure that actual threshold voltage, then "PAD1/ZC setpoint" on the MS3X card is available to carefully measure it.

James

[dfzuntor]

Hi people. Can I use a 12 v second cam trigger + a 1k pullup to pt4??

[jsmcortina]

So long as the voltage at PT4 does not exceed 12V.EDIT: MAX 5V. DO NOT EXCEED 5V.

James

[dfzuntor]

So long as the voltage at PT4 does not exceed 12V.

James

Maybe a max of 14V ???

[jsmcortina]

So long as the voltage at PT4 does not exceed 12V.

James

Maybe a max of 14V ???

I mistyped. PT4 is MAXIMUM 5V.

James

[jsmcortina]

I've just found a small bug in the firmware that _might_ have impacted VVT users in all firmwares up to and including pre-1.1 beta19.
It looks like there might have been a conflict between an EAE setting and VVT causing the cam position to be miscalculated. This is addressed ready for beta20.

James