MartinS Posted August 20, 2022 Report Share Posted August 20, 2022 Hi, continuing to progress with my Subaru EZ36 tune. Having a 2 similar problems which are stumping me with digital inputs. I've wired DI2 to be RH Intake VVT pos sensor and DI5 to be ground speed sensor. Everything looks fine and the wiring is correct for both. The runtime and all other indicators say those two inputs are 'off' at all times and I'm not sure why. The VVT sensor is wired the same as the LH intake (which goes to 'trigger sensor 2') but works fine. Could this be a bad sensor? Strangely, one day the ground speed sensor started working but was jumping around randomly so, following 'help' file info, I switched it to 'falling edge': no signal, switched back, no signal. The speed sensor is a 5V supplied by Subarugears which reads off the 5 lobe axle output shaft on the trans. Has power (light on) and is grounded. I've snugged it up to the axle shaft so there's almost no air gap... Am I missing something simple or should I go through everything again? Sorry, should read: LH intake pos works fine. Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 21, 2022 Author Report Share Posted August 21, 2022 I may have solved the speed sensor issue. On reading online posts it looks like this unit is the same as the Buslab unit (maybe that's where I got it actually) which can be hooked up as 5V for Subaru ECU's but also 12V for others. I have it hooked up as 5V, will try switching to 12V power supply. Hopefully that will give a stronger signal. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 21, 2022 Report Share Posted August 21, 2022 Are the pull-ups on? Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 22, 2022 Author Report Share Posted August 22, 2022 I tried both with pull-ups on and off, made no difference... Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 22, 2022 Report Share Posted August 22, 2022 If the sensors are 3 wire then pull-ups should be on, if 2 wire then pull-ups off. With the speed DI, assuming 3 wire, if you unplug the sensor and short the signal pin to ground with a paperclip or piece of wire etc, the DI should turn on for a second or two everytime you touch the signal to ground or remove the ground. For the cam sensor you can do a similar test, you will have to temporarily change it to "GP input", pull-up on, ground the signal wire should show "ON". If neither of these work then check you have 12V coming out of that signal wire with nothing connected. Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 22, 2022 Author Report Share Posted August 22, 2022 Ah, thanks Adam, I didn't know this about the sensors. Will do testing... Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 25, 2022 Author Report Share Posted August 25, 2022 Ok, trouble shooting on VVT input done (haven't tackled the speed input yet). Now have a signal on RH intake as well as RH/LH exh cam pos sensors (although I won't be able to run the exhaust VVT as I don't have enough outputs with the e-throttle module taking up one too many. I didn't realize I also have to turn on Dig1 as LH intake sensor even though it's also trig 2. The strange thing now is: on the runtime tables, I have a signal from Dig inputs 1 and 2 and they say they are LH and RH intake cam sensors respectively (which is right). At idle (700rpm), with the lockout set at 500 RPM, the LH intake says there is a 'sync error' and it counts approximately one error per second on the counter. The RH intake sensor has no errors until the RPM gets above about 1000RPM then error counts accumulate quickly. During all this, if I look at the trigger page, there are no trigger 2 errors at all (which is the LH intake cam sensor) and the engine runs well. Can't say I understand why LH intake sensor would be working fine as Trigger 2 but accumulating errors as LH Int pos sensor. Not sure what to do about this... Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 25, 2022 Report Share Posted August 25, 2022 LH inlet should only be connected to trig 2 and only trig 2 should be set to LH Inlet. RH Inlet should be the only one connected to a DI. Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 26, 2022 Author Report Share Posted August 26, 2022 Hmmm, mine is set exactly the same except I turned Dig 1 on (now off) and my trig 2 offset is 190.0 ATDC. I've tried to find this info online with no luck so I'm going to assume you're correct (which has always gone well for me!) and re-set mine to 130. Does it make sense my engine would have been running fine with the LH Inlet cam offset at 190 deg? Also, most of my filtering is set at level 2 or 3 which I think I turned up months ago when I was having trigger issues. Have turned them all back down to Level 1. Being 190 instead of 130 would explain the 'synch error' I assume... Will run cam angle test... Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 26, 2022 Report Share Posted August 26, 2022 The offset will be different for every engine. With engine warm and at fast idle above the VVT lockout RPM, run the cam angle test, note down the smallest absolute angle reported, this is your offset. Test pulse count for the cam angle test is 3. Do this for both cams. Filtering level 1 or 2 would be fine. Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 29, 2022 Author Report Share Posted August 29, 2022 Cam angle test done, with new numbers, both cam angle sensors able to 'sync' with cams at 0 degrees with blank target table, played with cam angle target table, cam angle positions in runtime values say the cam angles matched table, seemed to be working!! Entered in a conservative tune on the cam angle target table (ramped up cam angle to a peak of 30% advance at WOT between 2500 and 3500 ROM tapering up from 1200 RPM and MAP of 10, ramping down above 3500 RPM). Cam angle sensor says it's working, drove the van...HOLY CRAP, there's a lot of torque I'd left on the table which I'd only been able to access above 4000 RPM without intake VVT! So worthwhile doing this. Next question: do you or anyone else have an example of near stock VVT tuning for an EZ36 engine or know where I can find one? A photo of a table would be fine. I understand the principal and that intake timing advance is for lower-mid RPM but I won't be able to get the vehicle to a tuner with a dyno and LINK experience for some time and would like to have a conservative tune in place. It's a heavy vehicle and just the little bit more torque I've found has made a huge difference to drivability. Final question: I haven't looked at the speed sensor yet but am I correct in thinking the G4 cannot act as a cruise control anyway so there's no rush for me to fix it as that is the reason I wanted a speed sensor? Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 29, 2022 Report Share Posted August 29, 2022 Inlet VVT target from our WRX, probably a decent starting point. Correct you dont have cruise control capability with that ecu. The speed sensor is quite nice to have as an extra lockout for idle control. How much it is needed I have found depends on your driving style a lot. I tend to clutch in when coasting up to traffic lights etc, so speed lockout doesnt make much difference in that case. But I have had customers that have complained of regular stalling before, and when I go for a drive around the block with them I find they tend to overrun all the way up to a stop, so with no speed lockout in that case the idle valve (or DBW throttle) will close during over-run (as idle control is trying to pull RPM down to idle speed), then when they finally clutch in there is no air in the manifold so the engine stalls. Quote Link to comment Share on other sites More sharing options...
MartinS Posted August 31, 2022 Author Report Share Posted August 31, 2022 You know, that happens to me...and I do tend to engine brake until late. Wasn't stalling much at all until we got some 37 degree temps last 3-4 days and it's been happening more often. I will get the speed sensor working (will need it when I upgrade to get cruise control and Exhaust VVT going) and try that as a lockout. Although mine much more gradual so far, it looks very similar to your VVT settings table for the WRX so I think I'm on the right track. I'm up to a max of about 35 deg from about 2500 to 3500, looks like I can be a little bit more aggressive (the 3.6 has up to 50 deg intake advance) and will spread the range a little. Is making a HUGE difference to drivability. Much more than I thought it would. Thanks for all your help Adam, despite all my discouraging initial trigger issues, this is turning out better than I'd hoped! Quote Link to comment Share on other sites More sharing options...
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