VVT box woes.... Please Help
 

So I recently installed Megasquirt and attempted to get the VVT box running with it.
Car is an 01 running on Rev built MS2
I've got the car running great on MS alone. No problems. It's only when I try to get the VVT box working as well I've got issues.

At first I had a communication issue because I had the wrong type of 2.5mm cable. I corrected that issue now and I'm talking to the box via the VVT Tuner software.
I went online and read the tables on it. I loaded up the base map from diypnp (pid and table values both). I burned that info to the box. I also noticed that under the controller tab in the software there's a setting for "output trigger type". The only one the car will start on is "nb2 inverted".

The car will barely run. It stumbles and sounds terrible.
I attached a log from it on my attempts to start it and it running really bad.
I was wondering if anyone out there had some suggestions?
Possibly some different pid values to use?
No matter what I do it seems to target 20 degrees of advance and actually run at -30 degrees - or that is what it says anyway....
Also I tried to flash the firmware that came with the software download from diy. But I can't seem to get that to work correctly. I noticed there is the option to flash the firmware from inside the software. When you click that it gives you some instructions. Part of the instructions refers to putting a jumper on the ccm. The only jumpers I'm aware of are the ones on the MS that you use if you want to use the box or not. I tried the process with those on the ms and it doesn't work.
Does anyone know if you actually have to put a jumper somewhere on the VVT box itself in order to flash the firmware?

Any help is greatly appreciated.

I thought it only ran with "nb2 passthru"? Or maybe I misheard you.

if it's talking about a jumper on the CCM that's gonna be on the VVT box itself, inside the case. Might be more info on the VVTuner page on DIYauto.

it's the one on the bottom of the tab for the output trigger type -
i just just said it and wasn't sure - i don't even remember what i said...

inverted is last... whatever.

for reference... this is the table/settings you were using right?

https://www.miataturbo.net/attachmen...ine=1340753901

yes exactly
at one point i even tried zeroing out everything up to 3500rpm and all the way to the top on map just to see what it would do -
same results...

What happens if you unplug the connector from the VVT solenoid?

i tried that too -
either way with the vvt box hooked up and no jumpers or with no vvt box and jumpers the car idles but when you rev it, it's sluggish -
takes a sec to respond
the only way it runs normal is w/ just the ms - jumpers on and vvt solenoid plugged in

Wait, if you have the VVT box connected, jumpers OFF and the VVT solenoid connector disconnected, does it it idle nicely? Have you actually tested it as I describe?

yes i have
i have tested it in just about all possible ways

the answer to the question you ask is -
with vvt box connected and jumpers off and the solenoid disconnected it idles fine, but is sluggish when you rev it

i'm really curious about this firmware flash procedure and doing it correctly -
if i need to put a jumper on the vvt box to do it i need to know where....

But its not sluggish without the VVT box connected at all? The original basemap that was provided was for use WITH the VVT controller, and strictly speaking, the VVT engine is in fact sluggish down low when the VVT is not controlled.

Anyway, the problem appears to be that the VVTuner is commanding full advance all the time; PM me to troubleshoot this through email.

ok so i figured out the procedure for flashing new firmware -
i opened up the vvt box and in this pic in the upper right corner you can see the boot jumper the flash instructions refer to
https://www.miataturbo.net/attachmen...ine=1340901816

i flashed the .hex file that came with the download from diy

unfortunately no effect - for some reason the box continues to command full advance at 30 degrees no matter what - even though the table calls for much lower numbers

the only question about the hardware i'm left with now is about the white phillips head plastic screw shown in the lower right corner of this pic as well
i thought it was just a place filler, but now i can see that it's actually connected to something on the board

i've also been in communication with matt at diy about this
hoping for some potential answers
pid settings?
different firmware flash file?
white screw?

does anyone out there in miata turbo land actually use this thing????

If you see that the commanded advance is 30*, while the cells in the table dictate say 0*, then there is something very wrong with the VVT controller. DIY should be able to help you here. Can you take a vid of this?

I'm running the VVTuner on my car (and several other cars) with no problems so far.

-

wow
sharp eye on the parts on the parts on the board
abaloonflies had this first then miatakenji
i'm not sure that the vvt ever actually worked for either of them...

I"m asking Matt at DIY about this..

My VVT tuner didn't have the optoisolator in there as well. I was curious about it as well, but it does appear to work without problems.

ugh
hope crusher

Well, I was talking with Ben at DIY, I would be in just to buy the PCB and Processor, I am trying to figure out the material needed, these are the only pictures I founded, and the only item which was not foundable was the U2...

Even without schematic, a virgin PCB and a Bill of material is enough to build it. IMO

The optoisolator was causing a few issues with certain setups or cars, so we bypassed it.

It worked perfectly. The part went NLA so we found a way to bypass it.

*if* you had the optoisolator, probably. But as we had to bypass it, you'd need a schematic. We felt that this would be too difficult for the average user to assemble, so that's why we do not offer VVTuner in unassembled kit form.

-

So I'm back again with more issues on this -


I purchased a brand new VVT box from DIY this week and I'm still in the same boat -
Attempts to start look exactly the same on the screen/logs as before -
I"m seeing the box, I'm loading the base map, and I"m attempting to start with jumpers off the ms2 board
Box has everything it's supposed to and is powered on -
NO GO

So if anyone has suggestions on potential next steps for troubleshooting I would very much appreciate it....

Quick question - The car ran smoothly on the stock ecu before all of this
If the vvt solenoid was bad and I was running no vvt on the stock ecu would I know?
Would I have a DTC/LIght?
Would it run like crap?

Also are there any other settings in tuner studio I need to address here in order to make the vvt box function? Vvt box is powered thru ms2 but I'm doing all comm w it independently
Please help....

Thanks to anyone, Chris

Edit
Another quick note -
Under the output trigger type option I have attempted to use all 4 settings
With none the car will not start at all
With 91-97 na the car will not start at all
With 01-05 passthrough the car sound like its going to start but sputter and make some really nasty noises
With 01-05 inverted the car will start and idle like crap - the target advance will read what's in the table but the cam advance will read -33 to-34

More troubleshooting

Using this guide -
VVTuner Standalone Programmable VVT Controller Troubleshooting Guide
on 01-05 passthrough attempted some of the troubleshooting steps
after looking at the log i've attached i thought i might need to go down the path of the 2nd problem listed
so i tried p=20 i=15 d=0
and i did that datalog
i changed the duty cycle limits to max 100% and min 10%
still same results..

some big questions i'm left with here -
what settings is output trigger type supposed to be on??? there are 2 for nb2? is this dependent on wiring in ms2?

i can only assume the crankshaft trigger wheel is correct - otherwise wouldn't ms fail to run the car correctly w/out vvt

can someone point me in the right direction of each pin and what it needs to be connected to on the board in order for this thing to work correctly? i have the plug pinout for the vvt box

i stopped by the local dealer today and discovered a new solenoid (vvt) is $310
i have a hard time buying that given the car ran before i installed ms w/ no issues

Kindly remind which MS2 you have, I remember its a used one so I don't have your username in my database.

With the cam/crank signals going through the VVTuner to the MS the setting should be NB inverted.
If you are splitting the signal there is some things to play with regarding pullup/down resistors (I skipped that part).

Make a small harness to enable running the MS without the VVTuner, it helps keep the mind sane when you can troubleshoot in steps.

Regarding the absurd advance, check the OCV limits, especially the lower limit (was set to 30% for me). A too high lower limit will advance the cam with rising oil pressure regardless what target the tables have.

No, I have not read the whole thread, just wanted to share some of my headaches with a similar setup.

this was origionally built for user
aballoonflies from this thread
https://www.miataturbo.net/ms-labs-m...oup-buy-50791/
s/n: 10019

thanks

hey thank for the response
i'm hoping i won't have to bypass the ms all together, but i was thinking of it at this point
according to this i've got 15 pins on the connector
looks like i need wiring to the camshaft pos sensor
the crankshaft pos sensor
several grounds switched ign and a few other things including the actual vvt solenoid
i'm a bit confused on the diagram for a few other things an not sure what to do about the stuff refereed to inside ms
any chance you could give me the laymen's breakdown to where each wire needs to go 1-15?
i mean i don't need pics or anything, just description

In my specific case (my own wiring between my DIYPNP and the VVTuner) I made a DB15 connection with just routed the cam and crank sensor signals back into the DIYPNP, so they ended up where they were before I added the VVTuner (the DIYPNP ran a 99 engine in the same car before). This was just a smalkl plug I could switch in when I was feeling uncertain of my ability or the condiditon of the VVTuner.

With the VVTuner in place the Cam and Crank sensor signals enter my DIYPNP by the stock harness and are connected directly to the DB15 for the VVTuner with no other connection in the DIYPNP.
The signals back from the VVTuner in the DB15 are then connected to the appropriate place on the DIYPNP board.

The power and grounds are close to obvious.

you probably have to change your pull-up on the crank/cam like everyone else with a DIYPNP and VVTuner.

any threads or links to the specifics of what's got to be changed on the board?

edit

well i think aaronc7 has found the resistor i need to change from 12v to 5v pictured here

https://www.miataturbo.net/attachmen...ine=1374127935

it's opt 0 and apparently another user gorillazfan was having the same issue as me and figured it out...
hoping rev can weigh in on thoughts here...

just that one resistor to opto+, not the diode.

Yeah, I found another thread from April/May time frame where 'gorillazfan' was having the exact same issues as Chris. He ended up changing OPTO+ to 5v from 12v and it worked like a charm.

OK so i changed the resistor and still fail city lol
I when i turn the ocv min limits down to 0 i can get the car to idle really crappy on inverted
This is basically the same results I've had all along
But
I've got some more data to look at here -
The first thing that smacks me in the face is this
Check out the rpm on the vvt tuner software vs ts

https://www.miataturbo.net/attachmen...ine=1374164722

Also I've attached a normal datalog and a composite datalog

So I guess the way the vvt box sees rpm is wacked? How do I go about fixing that.....

We really gotta figure out how your crap is actually wired up. You were told to remove the 2 jumpers on the MS board if VVTuner installed, or install them with VVTuner uninstalled. We're not even sure if the cam/crank signal is getting sent to the VVTuner only, or if they are being split and being sent to VVTuner and MS independently.

Your composite log- the crank signal looks a bit wonky, at least they do not look like gorillazfan's. Actually it looks 'inverted', so maybe it's safe to assume that yours is wired up such that the sensors are going to the VVTuner only, then being forwarded onto MS. That still doesn't explain why your VVTuner is getting a weird RPM reading and MS seems to be getting RPM fine.

I say try wiring it up like gorillaz- split the cam/crank signals and send them to VVTuner and MS separately....then mess with the pullups as needed (you may already be squared away there).

We've been working on this the past few hours, think we might be getting close. We split the cam/crank signals to both the VVTuner and MS separately. Got a good rpm readout in VVTuner, but now MS is always showing 0 RPM. Did a composite log, and the cam signal looks normal, but crank signal is blank. I'm guessing this means we need to change the pullup on the crank/OPTO+? Any other thoughts? Getting very frustrated trying to get this thing to work.

Attached is last cranking composite log.

what's it at? 12v still?

We switched it over to 5v and got this result which is confusing us even more-- everything I have found on here said that switching from 12 TO 5v fixed the issue when sharing the sensor. Perhaps a bad wire connection..... ugh.

Initially we had the cam/crank signals backwards going to the MS (oops), with both pull ups to set 5v. You could see each signal fine in composite log, they were just backwards. So I switched the wires and now we're running into this issue.

so after 6 long hours of messing with this thing we got it running
several combos of stuff happened before we actually got it right
here's some highlights -

vvt box is getting cam and crank sig straight from the factory wiring
the colors of the wires were reversed for cam and crank (sig) from the board to the plug - we traced them back to opt 0 and vr2 according to what diy's site said for what they should be
when i first opened up the vvt plug i discovered there was only one wire going to the ocv - i added the 2nd wire to the plug and both of those wires are also directly wired into the stock wiring
the jumpers are on and i have just 4 wires into the stock wiring
opt 0 is on 5v
it works :)

Welp, at the end of the day it was really just some confusion/false assumptions we made early on about how the ECU routed some of the signals around that caused our issues....glad it's all sorted out now.

Basically we followed the picture that Braineack posted and it worked great, with 5v pullup for OPTO+.

So over the last few days I had intermittent issues with seeing correct rpm on both vvt box and ms at the same time. I figured it had to be a connection issue with either a stupid butt end connector or one of the clip on thing we used splice into the factory harness. I went over the wiring 3 or 4 times trying to check it all and couldn't get it to work every time I started it up.
So I figured the inside of the plug on the ms was the same as the actual factory harness itself -

So i started to pull everything out and I drew some fancy diagrams -

https://www.miataturbo.net/attachmen...ine=1375494678
https://www.miataturbo.net/attachmen...ine=1375494678

Then I asked a buddy of mine that actually know wtf he's doing when it comes to soldering to add the 4 wires I needed for cam sig, crank sig, ocv + and ocv - on the inside of the plug

https://www.miataturbo.net/attachmen...ine=1375494678

Then he soldered those wires back to the vvt box plug and we closed the whole thing back up - put a new wire loom on it and I'm back to having an actual pnp setup again -
https://www.miataturbo.net/attachmen...ine=1375494678

I installed it again and it runs like a champ -

Drove around for a while tonight and let VE analyzer do it's thing to correct AFR now that I'm running VVT
:)

If anyone has any slightly more aggressive base maps for VVT on ms2 (NA)I'd love to give them a try...

Good thread. I MAY be going this route so I'll keep all of this stuff in the back of my head.

Happy to see it finally working well.... Now, my turn- hopefully no phail *crosses fingers*.

I'm running into a very similar issue; I can get it to start using NB inverted crank signal, but it idles like crap. My MS and VVTuner are getting the same RPMs though, and Rev says my MS has already got the 5v pullup. Was the ultimate solution to split the cam and crank signals to go to the MS and VVTuner separately, instead of going through the VVTuner to the MS? Or was that only necessary to fix the RPM reading issue? Mine shows that it's targeting around 20 degrees of advance, and it's actually getting around 46 degrees, which sounds very similar to what cpolly was running into originally; how did you guys fix that?

Thanks!

I bypassed the ms board all together. I pulled everything I needed from the ms side of the factory harness connection point. So basically intercepting the signals before they are even getting to the ms board. I drew some pics of the factory plugs and exactly what was needed on the page before.