2GR-FE Cam Triggering Help Required

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MikeyB571
Posts: 42
Joined: Sat Nov 26, 2011 12:05 pm

2GR-FE Cam Triggering Help Required

Post by MikeyB571 »

I'm just completing my installation of a 2GR-FE Toyota V6 in my MR2 and I'm having trouble trying to figure out how I should setup the cam sync.
This engine has dual VVTi, but initially I'm just trying to get 720 Sync using one of the cam sensors as the main one.

But, the Cam have a really weird trigger, each has three teeth all of different sizes. Can someone help me understand how to configure the Cam trigger to cope with this.

I have a sync log, links below.
https://www.dropbox.com/s/fqrts7hwzgwy6 ... E.txt?dl=0
https://www.dropbox.com/s/ne54yd9v6sfsr ... g.PNG?dl=0


Thanks in advance,
Michael.

stevieturbo
Posts: 932
Joined: Sun Dec 07, 2008 2:04 pm

Re: 2GR-FE Cam Triggering Help Required

Post by stevieturbo »

https://www.youtube.com/watch?v=xQcv9YK-DQ0&

viewtopic.php?f=6&t=582&p=2936

viewtopic.php?f=4&t=1088&p=6201

And maybe this might help too.

For the basic trigger...the width of the teeth dont matter as much....as where the rising or falling edges are, and which you choose to use.

You could just open manual cam checklist and open a small window in one phase that sees one edge only that is unique to that phase, and ignore the rest. That would get you into 720 in a very basic sense. Doubt it would be any use for the VVT aspects though, and even if it was you'd need to make that window wide enough so it's always seen in the chosen location with VVT movements taken into account.

But it looks like a 36-2 crank, fairly common with Toyotas, cam as below.

This screenshot shows a full 720 cycle, from where you've told it TDC cyl1 ( and whatever cyl it pairs with too ) in relation to the missing tooth.. If we assume for now first half is 0-360, and second 360-720

In the first phase, we have 2 distinct rising edges. But in the second phase only 1 rising edge. So you could do two cam checklist windows just like that. 0-360 and 360-720, expecting to see 2 teeth in first, and 1 tooth in the second. ( with cam sensor configured for rising edge etc )
Or if you chose falling edge, it would be the other way around, with only 1 in 0-360, and 2 in 360-720.

If you did it like that and it wouldnt start as it's 180 out...you could just change from rising edge to falling edge instead of swapping the checklist.

0-360 yellow bar to white bar, 360-720 white bar to green bar. ( assumed as I do not know where your actual cyl 1 is )
toyota cam trigger.jpg
toyota cam trigger.jpg (342.57 KiB) Viewed 4311 times

Or email Syvecs support....they'll be better at it than me lol.

stevieturbo
Posts: 932
Joined: Sun Dec 07, 2008 2:04 pm

Re: 2GR-FE Cam Triggering Help Required

Post by stevieturbo »

or to find cyl 1 TDC relative to the crank teeth on a log ( if you cant see the trigger to do it manually or something )

green line at bottom is a pressure sensor hooked up to cyl1. Top graph is the raw AN crank/cam, in my case 36-1 with just a large single tooth for phase.

Here TDC cyl 1 can clearly be seen at the falling edge of the cam tooth, and you could count teeth or scale to get a starting crank ref tooth angle ( in my case 301deg ATDC )

Would be nice to be able to overlay a 720 cycle between chosen points in SView.

cyl1 pressure.jpg
cyl1 pressure.jpg (282.3 KiB) Viewed 4309 times

MikeyB571
Posts: 42
Joined: Sat Nov 26, 2011 12:05 pm

Re: 2GR-FE Cam Triggering Help Required

Post by MikeyB571 »

Thanks for taking the time to post up, that was very helpful.
The link you posted was really helpful also, and your ideas make sense, so I appreciate that.

I've gone through Pat's great explanation and I tried his procedure, which highlighted to me the reason why I am currently unable to make any progress in getting a 720 sync. Basically my signal is not being interpreted, I see a raw voltage which goes between ~0.5v to ~3.5v but if I look at the RawCAM gauge I get nothing.

The Cam sensors are hall effect and I'm setting the sensor type to thermistor for a pull up, if I don't then I get no voltage variance at all. I suppose it's possible that I've wired the sensor wrong and have the 5v and sensor ground swapped. But fundamentally the ECU is seeing a good voltage range from this sensor so I don't understand why it won't detect a rising edge (I did try setting to falling edge also and I've tried changing the thresholds to suit the voltage range I'm seeing).

I'm pretty stumped, does anyone have any ideas of what might be wrong?

Perhaps I need to make sure that the hall effect sensor is outputting a certain spec?

stevieturbo
Posts: 932
Joined: Sun Dec 07, 2008 2:04 pm

Re: 2GR-FE Cam Triggering Help Required

Post by stevieturbo »

CamRAW is a position, not a voltage.

From the scope, it is very clear you are getting valid signals.

If you want to see/log these on a datalog as raw voltages, then log those AN channels.

If you have not set all settings for the sensors/triggers correctly then it will never be able to determine a position in camraw, because although the inputs receive signals...it will not know what they are.

MikeyB571
Posts: 42
Joined: Sat Nov 26, 2011 12:05 pm

Re: 2GR-FE Cam Triggering Help Required

Post by MikeyB571 »

Hey Stevie,

I really appreciate all the support and you have absolutely helped me get up and running.

I believe because I am using a voltage input for the cam signal (as apposed to a bipolar input), the ECU is using some predefined threshold for triggering and the voltage range my sensor was producing using the internal pullup wasn't enough.
I have now used a 2.2KOhms physical resistor and have managed to get the ECU to recognise the cam sensor rising edge.

I have also managed to obtain a stable 720 sync :)

It would be nice to find a way to get it to work without the pullup resistor though.

Now I just need to get the VVT to work.

MikeyB571
Posts: 42
Joined: Sat Nov 26, 2011 12:05 pm

Re: 2GR-FE Cam Triggering Help Required

Post by MikeyB571 »

Regarding the use of RawCam gauge, I did this following Pat's procedure Just to get the angles to use in the Manual Cam Checklist. But when it wasn't producing any values, that clued me in to think that the ECU wasn't able to trigger on the signal levels I was providing.

stevieturbo
Posts: 932
Joined: Sun Dec 07, 2008 2:04 pm

Re: 2GR-FE Cam Triggering Help Required

Post by stevieturbo »

I think Ryans video did mention some inputs are better suited than others, although hall effect should be straightforward, so use an input where you can select the trigger voltage thresholds.

Although it should be very easy to repin the S6 I or Plus connectors very easily if you wanted to use a different input.

But if it works with a physical pullup....it works.

MikeyB571
Posts: 42
Joined: Sat Nov 26, 2011 12:05 pm

Re: 2GR-FE Cam Triggering Help Required

Post by MikeyB571 »

I don't have enough Bipolar inputs unfortunately as I have four Cam sensors and a Crank sensor to cater for, not to mention ABS sensor etc...

So I'll just add the pullup resistors, no big deal.

Thanks again for your help.

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