VVT Not Enabled
 

Chasing an issue with VVT staying at 0 in my car. Here's what I've done so far-

Checked my clamped vacuum lines on the solenoid under the intake plenum
Checked for vacuum leaks overall
Re-flashed my tune and reset the ECU by removing battery power with all accessories on for 30 minutes
Started car and did not touch gas pedal for 15 minutes
Reverted to first tune revision for car when turbo was installed
Reset ECU the same way I did before
Started car with the car already hot, no gas pedal for 15 min

VVT still will not enable.
One cam in ECUTEK is not cycling until I start driving the car, it is exhaust bank 2.
I replaced the OCV solenoid with a known good one and reset ECU again.

My question also is this: does exhaust bank 2 normally not oscillate with the other 3 cams, or is the actual OCV probably filled with gunk?

This started with sudden loss of power in most of the load map one morning. Idatalogged and found that VVT isn't turning on, which is why the car isn't building boost quick and has 1/4 of it's power in positive boost pressure load areas because there's no timing from VVT.

The picture below shows 3 of the 4 cams oscillating during a cold start cycle, and exhaust bank 2 sitting calmly at 0.

https://i.imgur.com/vbcnXyi.jpg

Thank you for any insight. The car has no other trouble other than it runs like shit in most of the load map.

Car is a 2013 FRS running at custom turbo setup. Stock engine, ECUTEK is my tuning platform and I'm using A01C revision since B01C bugs out with Racerom. Car has been turbo and had 63 tune flashes with no issue and 9,000 miles.

I had the same issue and it was a bad cam angle sensor. Not the solenoid, but the actual sensor.

Thank you! I have a spare, I'll swap it. I've nothing to lose, so why not!

Until Tonrogs' reply, without codes, I would've never guessed. Awesome insight.

a hint is that vvt exhaust reached negative values
Exhaust cams aren't allowed to go advanced past 0 so that is a false logging, so I also think is the cam angle sensor
Also cheap to buy, but be aware it needs a really careness to install because the distance must be corrected with special gaskets if needed, to have around 1.3mm of distance between the sensor and the cam plate

Otherwise you can induce misfires, there is a TSB explaining very well this

I mean, just install it, but if you get cel and misfire at least you know why

I replaced it. VVT hasn't come on but exhaust bank 2 is reading now! It won't 0 out though, it's hovering around +3 degrees. I'll reset the ECU again and see what happens. No CEL or misfire :)

Hope it fixes, could also be the cam actuator that went bad, if it struggles to go to 0

Does it follow the other exh cam?
Does it swing or steady at a value while idling?

Steady value. Other cam hovers around 0 so no, it's not following the same value but it does follow the up/down trend while driving.

EDIT: After letting it idle for 10 minutes, it is following the other cam and zeroing out. I went for a 5 minute drive, still not activating

Here's a datalog - https://datazap.me/u/darkpira7e/no-v...?log=0&data=24

tricky
post a log of prolonged idling with warm oil and idle under 950 rpm, with all VVT loggable values activated maybe...

I think bank 2 exhaust is still mostly dead. I bet that long stretch and chunks of perfectly zero indicate lack of signal.

i don't know, i also get sometime an evenly 0 in my exhaust side, a looot more smoother than intake
and don t have problems
Also i think a lack of signal could have thrown a CEL
and misfires, since cam angle sensors are used to dictate the firing order

but only one bank? o.0


I'm also surprised no CEL.

this engine is weird, and his oil channels too,

i too have super steady exhaust cams, and stupid retarded-responding intake cams, but no problem at all
I think there is something else in his car stopping the vvt to enable

Did you have the famous valve recall that affects someway the cam oil channels?

What weight oil are you using?
Does it idle well after a cold start?
Will your vvt come on after you drive for a while?
One thing I had done is use techstream to manually control each solenoid while idling to rule out both a faulty solenoid and to be sure I was using a decent oil weight on my built motor.
From there it was checking logs to see that I was getting bad reading from a sensor causing the vvt to come on about 15 minutes into my drive.
I never had a code thrown for this myself either.
Since I had my stock engine sitting in my garage, I just swapped all 4 sensors and the problem was fixed.

Lastly, here is a snip from a reply from James Martin when I was having this issue.

"Grab a log of it idling, and specifically watch the cam sensors and see if they move (read anything other than 0-0.1) while vvt enabled == 0. "

Ignore, multi post

I was one of the first to have catastrophic engine failure because of it; I started the registry and discussion threads. I'm on my 3rd engine. This engine reportedly did NOT have the recall work done. Bet your ass I inspected the casehalves once I got it home to look for evidence of tampering. It's been good since last May and I put it through hell when I got it back.

@Tonrogs I run a 0w-20 Royal Purple synthetic. For no reason other than I've always run it and I get a deal through my local performance shop.
I'll get a log of it idling :) I do know in my time monitoring it I haven't noticed them being over 0.1, what does that mean if they do?
I'll go for a long drive to see. So far driving around hasn't enabled it, and it idles really well. It's never had idle trouble. I have the idle set to 900 right now. I set it to 700 in a previous re-flash to troubleshoot this and saw no improvement

keep anyway idle under 900 for now, and do a bit of driving just to put oil over 35 Celsius then just let it idle and log it

https://datazap.me/u/darkpira7e/idle...?log=0&data=17

Here's a log after a 45 minute drive, idling in my driveway. VVT status still 0. interestingly enough, now an intake cam is having a hard time reading 0 to 0.1

vvt ocv duty #1 #2 are supposed to be more than 50% and no current is flowing in your ocv intake sides

Now i go to my car and reflash to force vvt enabled 0 and check the values of the ocvs in my car with vvt disabled

nope, sorry
mine do exactly the same
but then when oil reaches 32 C it activates and current flows through ocv intake

https://datazap.me/u/tommbrz/cold-start?log=0&data=25

i have no idea, hope it's not mechanical problem like something blocking oil

i just replicated involuntary your problem

after that log i did a little trip with the car until oil and coolant were warm/hot
then turned off and after 5 min i drove home

well, on the second startup the car was still super warm and vvt hasn't enabled yet

did a reflash, and a 5min trip, still vvt off

what i'll do, and you should try too, is: tomorrow when car is super cold, flash it again first then make the cold start and do NOT touch the throttle untill oil goes over 32 C.. if no problems, it should activate

the second start after a reflash is always bitchy, and now that i think about it, i never turned on again the car while still hot as a second start... I mean, it s strange but apparently i just replicated your conditions

This is not what I expected to see. Tomm, your vvt exhaust angle (1,2) fr values are reversed from Dark's. The ecutek tuning guide that I have is vague in this area. I understand that these values are in units of degrees but I don't know what 'fr' means. Are they relative to each other, or absolute?

It's as if Dark's system appears to be measuring normally but just doesn't enable. I hate not having a complete definition of the system.

i dont know, i have a 2017 car and they changed a bit the logic and also the shape of the cam plate

You guys might need to get Techstream amd check the VVT initial parameters and look for one cam that deviates from notmal reading
https://www.ft86club.com/forums/show...&postcount=337


If the intake cam deviates from avojt 60 or ghe exhaust from 90 initial by more than say 5 degrees it usually means a problem.

how hilarious it is that now my car has the same problem of his
VVT doesn t work anymore

I had a engine rebuild, I even changed the intake cam, car worked good for 10days, today i make a reset to see the values for Darkpirate after a reset and boom, vvt is now always 0
Cam intake #1 fluctuate between the 0 and never activate

I ll go to mechanic to change the oil and maybe he can see those values with the subaru ssm3

https://datazap.me/u/tommbrz/vvt?log...00-606-571-578

I was just about to suggest that, in the absence of better information, we eliminate some possibilities.

One would be to consider a jammed spool valve. It would be an ft86-first if you've discovered the issue early enough that the ecu hasn't adjusted itself out of its ability to recover.

The tip of the valve should plunge well below the face of its nearest neighbor. I have personally felt the subtle crunch of getting through something blocking it. In my case it was bank-1 intake.

edit:
omfg :bonk::popcorn:

Assuming everything works properly on startup, vvt should enable within 5 seconds. Typically right away.
Id start with techstream to narrow the possibilities.

@Ultramaroon
i ll show you a log of my car just after the rebuild
I threw a rod and bent intake cam #1 together with 2 intake valves
Subie mechanic didnt want to change the variator of that cam but in the log you can see how much it oscillated

https://datazap.me/u/tommbrz/prova-b...&data=12-30-31

Anyway, vvt activated always and after 30km it fixed itself and engine worked perfectly, as per log of today afternoon I posted before of a cold start

Then i started again the car and now vvt doesn t enable and cam intake #1 oscillates super quickly from - 0.6 to 1.1

Could be the variator that needs to be changed? is that spool valve part of it?

I'm going to try just changing out the oil. I shouldn't have to but it's worth a shot. Thanks for your participation everyone; maybe we can unravel more about the VVT system

I assume you do not have an oil pressure gauge?

Also, if you use techstream, you could rule out the oil as being a potential cause to this issue.

I don't have one, you're correct. I don't have techstream either. Might be worth getting

it definitely is worth getting. Just need a $15 adapter from ebay.
http://www.ft86club.com/forums/showthread.php?p=1920724

I am figuring out how to log using techstream. The UI is not quite... Well, it sucks.

When you say variator, could it be what I understand is called the phasor?

Hi,

I've experiencing non-moving AVCS issue also after repairing rocker arm exodus. When disabled, intake cams are not moving even in the Active Test of Techstream, but exhaust cams moving. Both are not moving in the Tactrix OP2 logs.

But after doing repeated engine braking, finally it works again. Like driving pattern for P000A, P0011, etc.

Attachment 184550

But don't know how long it takes whenever new map is loaded. Just keep doing above driving pattern until cams are moving.

I see that fuel cut when decelerating in region-D is emphasized. Without knowing exactly what does what, it still makes sense. I've noticed that, at no matter what RPM, in fuel cut (mode 4) the VVT angles lock to zero. The intake phasors have a spring-loaded zero lock. The exhaust phasors do not.

Yes sorry, i meant that
i bent that cam and mechanic assumed that from the shock, i needed to change also the 2 chains and other things correlated to them, but not the phasor.. but now i d really preferred to have changed it

I have one phasor that flutters too but I can only see it with tactrix sample rates. Unfortunately no one has the aim angle (input) parameters for tactrix definition files. Tonight I am trying to figure out how to get higher resolution from techstream.

i have techstream, i mean i ll just have to find again a cheap adaptor because for now all I have is ecutek but i'll do.
As Ultramaroon said its user interface is frustrating, can you help us find this thing we are talking about in it?

I read somewhere here in the forum that people needed to change the ecu because it stored wrong initial position values.. doesn t the ecu reset the value after a reset or. flash?