krispe

Hi Guys

Just checked again with my timing light. With the marks lined up as per the below picture the angle offset required was 10.5 degrees with the megasquirt set to fixed timing of 10degrees. I set it back to "use table" and checked again it now lines up at 14degrees as per my ignition table.




I have not checked however if the marks actually line up with TDC by physically put something in cylinder no.1 to see.

Here is a composite ignition log with the OCV unplugged: https://app.box.com/s/0nwgwh7bi97bjfm2pa2j

hustler

iTrader: (6)

Show us the tooth logger. I had a similar problem, it was a bad sensor out of the Mazda box.

krispe

One tooth log for you Hustler https://app.box.com/s/o4i8acivnm5a5o6pk15e



On a side note my VVT engine seems to run a bit warm? Seems to sit at 95/96 decrees C when driving/cruising, which means my radiator fan is also running, (it's set to come on at 95C on my Megasquirt). My 1.6 used to stay around 87-89C. I'm using the 01 temp sensors, (not my original MK1's) which I have spliced into the MK1 harness. Will the 01 VVT sensors give different readings to my old MK1 1.6 temp sensors? They will be a PITA to swap now, (I would have used them but did not see the removable grub screw on the back of the VVT engine for the temp gauge sensor until after I had fitted the engine, so I thought I needed to use the 3 pin 01 sensor instead).

krispe

I'll try setting the trigger offset back to zero, plug in my OCV and see what happens.

krispe

Quick update - followed Richy's suggestion and checked TDC with my dipstick in cylinder no.1. At the highest point the left mark on the pulley lines up with the T on the cover. Also at the sametime the nubs on the trigger wheel are in the correct place according to the picture Niklas posted. So the crank pulley/markings and trigger plate are correct but to get them to line up with the engine running means adjusting the angle offset by 10.5degrees!

What should I try next? This is all new to me and I don't really know what I should be doing, was hoping the engine swap would just happen without any issues?

I'm using DIYauto tunes VVT base map. Is it worth me modifying it by reducing the numbers in each cell by 10.5 degrees to match the offset I'm using?

Reverant

iTrader: (10)

Can you communicate with the VVTuner and read the duty cycle values from the software?

krispe

Hi Dimitris

I'm actually away from the car for a few days so can't check till after the weekend. I have been able to connect fine with the VVTtuner though through the new serial connector, so will check the OCV duty cycle when I get back.

Thanks

Chris

krispe

Duty cycle, warm idle. Limits are Min 25% max 80%. Should I have anything selected for Trigger Output? Its set to none (off)< I guess because on Reverants ECU it gets its reading direct from the ECU, not direct from the sensors.

Reverant

iTrader: (10)

Can you try going to 2500rpm in neutral and watch the duty cycle when the problem occurs? Report said duty cycle.

krispe

Ok duty cycle is in the low 30's. the problem happens at either 3000rpm+ or above 30kpa.Duty cycle does not really change when problem happens. It's kind of like a signal crash/clash. Engine splutters/dies for a split second, Rev counter bounces down and back up, clicking noise from behind the dash, like I just lose electrics or something. OCV unplugged car runs absolutely fine?

NiklasFalk

iTrader: (1)

Try to change the advance taget in the table to be max 24 degrees (or just zero, or 5,..), just to test if the log was telling anything (where it lost sync when the VVT target got above 25 in the msl). Start in the lower left corner and tab your way though the table (if you don't want to do off-line editing).

Just a question though, why was TS putting a VVT Target in the msl?
In my experience the VVTuner is very separate (and can log what it's doing as well).

If you can control the VVT angle to let's say 5 degrees all over revs and MAP, there should not be an electronic problem or software problem, but rather an mechanical problem with the location of the cam/crank nubs.
The ving at the back end of the VVT is just shrunk in place, no key at all. But if that's seriously wrong you would notice a strange Cam Advance in VVTuner with the OCV disconnected (-3 is normal IIRC).

Sorry if some of this have been mentioned/asked/answered before, disregard as needed

krispe

NiklasFalk - Any suggestions are gratefully received whether they have be mentioned before or not.


Set all my VVT table values to 5 and plugged back in the OCV and tried the car. Car works fine at all revs / map. I now need to increase the values until the problem occurs.

With the OCV disconnected the cam advance in VVT Tuner at idle is 3 (not -3), it's also 3 with the OCV plugged in? Seems to make little difference plugged in or not according to VVTuner?

Thanks again

Chris

NiklasFalk

iTrader: (1)

Logs from the VVTuner when you do those tests might reveal something when it fails.

With an advance of 3 as zero I see no way that the adjustment range would explain the loss of sync.

Or you can just run the poor thing with an advance below the level it craps out?

krispe

VVT Log https://app.box.com/s/n6bi124qk7okx857i536 With the target set at 17 degrees car is fine however at about 20/21 degrees I get the problem/signal crash. Even with the table set to a max of 17 I still get the odd crash when the VVT tuner sometimes overshoots the target, (pulled away from some traffic lights and cam angle jumped to 21 and problem occurred (electrical/spark cut? revs drop/bounce, car dies). Is there some way to reduce the occasional overshoot?

Any suggestions of things for me to try are gratefully received.

For now I can live with a an advance of 17, its better than nothing! I need to get my car tuned and ready for its trip to the Nurburgring and Spa in October.

NiklasFalk

iTrader: (1)

Row 2580-2628 does not look healthy (15890rpm for one).
Could it be that the VVTuner is creating this problem and shorts the cam sensor when resetting or something (and MS is reporting lost sensor)?
It looks to be two seconds of messy data before a reset (or whatever happens).

Or is the MS the culprit?
https://www.miataturbo.net/megasquir...31-32-a-65472/

krispe

This is where I am stuck, I have no idea if its my Rev MS2 with built in VVT Tuner or a dodgy sensor. I've emailed Reverant to see if he has any other suggestions I can try to find the cause?

krispe

Ok Quick Update. Above 20degrees I get the problem/signal crash? So I have set the max target on my VVT table to 19 and need to play with my PID settings to prevent the overshoot I'm getting which can trigger the problem. Not ideal as I'd like to be able to try the settings recommended by DIYautotune , but at least a max of 19 advance has to be better than nothing?

What is the best way to tune PID? Which do I tune first? P, I or D?

Another thing that may be affecting my VVT is my oil? When I fitted the engine I used Millers Competition 10w-40 fully synth which is what I was using in my NA1.6 and seemed great on track. It is however very heavy for a 10w-40 and I've noticed my oil pressure gauge now seems very high. It seems I should be using a lighter grade for the VVT engine, so will try a high quality 5W-30, (Fuchs Titan Race Pro S instead). Car is used on track so I want something decent and not too low viscosity.

krispe

I'm now using the following P20, I10, D8 and a maximum target advance of 18degrees on my VVT table which is based on the original DIYautotune table but with 18 being the highest number. My PID probably needs tweaking further but at least I am no longer getting overshoot above 20+ degrees and the subsequent signal overlap/crash whatever it is???

Still not sure wether to just give up for now and pull the plug on the OCV and run without VVT :( I have a track day /road trip coming up so need to just get the car tuned and running well but running out of time and have no ideas on how to solve the VVT issue. Would it have made any difference if I had upgraded to MS3 rather than have a VVT Tuner wired into my MS2E case?