vvti problems

[Wabbitkilla]

Ok,

I'm posting this up as it could help people in future.
Let's just say I've lost some power, a fair bit of power.
Oil is good, maf is clean, intake filter is good, oil filter is good.
Not losing any fluids.

On the dyno we're seeing no vvti action, so we swapped the vvti ocv for another one (from another car with possible vvit problems it appears). With the ocv connected and disconnected there is no difference in the power curves.

With the ocv removed but plugged in (engine not running I hasten to add) switching ignition supplies 12v to the ocv.
Repeated switching of the ignition show occassional movement in the ocv .... definitely not every time, it would be nice to assume there would be a cycle like the IAC valve to show if it's working or not, but not having a known good vvti ocv it's hard to say if what we are seeing is to be expected or not. Saying that, using the pfc we replicated rising and falling rpm and the ocv didn't budge. We even tried it with the oem ecu ... no difference.

This is interesting reading;
 m http://www.motor.com/magazine/pdfs/042010_04.pdf m

So the ocv doesn't react to pure 12v or not 12v, it looks like the ecu feeds a pcm signal via the earth and thereby varying the extent to which the ocv valve moves in its housing. In my case it appears not to move at all so initial prognosis is that the ocv is buggered (technical term   s:lol: :lol: s:lol:  ) so I've ordered a replacement  from my local Mr T, £73+vat and delivered in two working days.

Now this engine has always had quality fully synthetic oil in it but has been used hard. It now has 85000 miles on it and when you think about it that little solenoid has been bouncing merrily away for a long time under hot conditions. The coil may be ok ... so you won't get an engine light on the standard ecu but it ain't budging.

This may be, by all means, not be the problem, it is only the start of the diagnosis and possible fix, I will keep you updated.
But it also got me to thinking, and I don't want to make people paranoid .... are there a number of other people running around out there where the power has dropped off in a similar slow way where you just get used to the car getting slower? Is there a quick and east way to check the ocv is functioning correctly? Hopefully following this thread when I've discovered the cause of the problem will help a few of you out there.

Many thanks to RS Tuning of Leeds for their time, understanding, and help yesterday ... I'll be back

[Wabbitkilla]

Additionally there is this from Toyota;
 m http://www.autoscorner.com/00%E2%80%930 ... letin.html m

But unless you have the Toyota test gear it's little help, but if by some miracle your vvti actuator has become locked then it shows how to release it.

And this is an easier to follow article
 m http://www.import-car.com/Article/47962 ... uator.aspx m

[Wabbitkilla]

Seems the Lexus cars have similar problems (hardly surprising as it's the same part)
 m http://www.clublexus.com/forums/perform ... ter-3.html m

[JiMR2]

Hi Nic,

Sorry to hear about the issues mate, sounds like your on top of it all though. Did the problem only become apparent on the dyno test or was it easily noticeable? ie, obvious lack of power @ 3.5k + rpm?

[Wabbitkilla]

I've been a bit disappointed in the power for a while, but figured it was just me being paranoid.
The I went to a dyno day and the power trace didn't correspond to the previous mapping session by a significant margin ... and then I thought "I wasn't being paranoid".   s:roll: :roll: s:roll:    s:lol: :lol: s:lol:  

I'm still well above standard power output but not enough to justify the modifications.
Compare the output to a standard car and the vvti "hump" isn't present.

I think it's one of those things that has come on gradually, you just tend to get used to things when they happen like that.

[ChrisGB]

Hi Nic

Looking at the dyno graphs posted in the N/A thread, looks like the problem started when you had the stage 1 cams fitted. The torque curve is showing exactly what I would expect from vvti not working. It could also be a result of increased valve overlap from the cams dropping mid range torque, but I would expect that from stage 2 or 3 cams.

The vvti function is quite complex, being load and speed related, and is controlled via pwm. A quick check to see if the valve is stuck is to put 12v across the valve when the engine is idling. If the valve is working, the engine should stumble or stall.

Chris

[Wabbitkilla]

Thanks Chris, that would indicate the valve moves with a 12v signal applied.
When you turn the ignition to on (without starting) there is a 12v supplied to the solenoid by the ecu .... it's not moving which suggests it's broken.
I actually agree with you, this engine has always been a bit down on torque, even before i started modifying to the larger degree.
Back at Hypersports it was noted after fitting the Markiii pipe and Blitz filter the torque was marginally out compared to a normal car.
When I bought the car it had effectively been stood in a  garage for 3 years, I wonder if it just gave up from lack of use?

[Anonymous]

I told you at ding day some of your horses had escaped!

[Wabbitkilla]

I told you at ding day some of your horses had escaped!

I remember Bry .... makes you wonder why Noble said nothing about the vvti not working the next time it was mapped?

[ChrisGB]

Thanks Chris, that would indicate the valve moves with a 12v signal applied.
When you turn the ignition to on (without starting) there is a 12v supplied to the solenoid by the ecu .... it's not moving which suggests it's broken.
I actually agree with you, this engine has always been a bit down on torque, even before i started modifying to the larger degree.
Back at Hypersports it was noted after fitting the Markiii pipe and Blitz filter the torque was marginally out compared to a normal car.
When I bought the car it had effectively been stood in a  garage for 3 years, I wonder if it just gave up from lack of use?

Compare the torque curves from before and after the Crower stage 1s. The pre cam mod diagram gives a pretty typical 1zz torque curve, but the post cam graph shows a completely different curve. Somewhere between these two dyno days is where it went awry.

Chris

[FGrob]

I've checked through my dyno's - which I've got a few of and they all have the kick at 4400 rpm the only concern for me is the torque shown originally at Hypersport was up around the 140 mark where now it's down to 136 ftlbs, but with a higher BHP, I think when we spoke last about this we put it down to the different dyno machines but now I'm having second thoughts, let's hope it sorts it for you Nic.

Rob.

[Wabbitkilla]

When I get the new OCV i'll see how it reacts to the ignition on/off and it may produce a simple test for everyone to use to see if the vvti ocv is US or not.
Depending on the result I will then consider looking into the actual vvti controller on the camshaft.

There is a very easy way to reset the camshaft controller with 20ft/lbs of air, but of course you need to take the cam cover off to do it.
At least it isn't dangerous to the engine, it only knocks a hole in your power.
AFR's still run clean and there's no detonation.

I'm planning on replacing the OCV when I get the new one, try a test outside of the engine, and then instal it and test it with the original Noble map when it appeared to be working normally. FC-Edit is a great tool   s:) s:)  

I don't have much time to do it all though as the part arrives sometime tomorrow and I go on holiday to Scotland on thrusday.   s:scared: :scared: s:scared:  
Laptop will be with me though so I can make changes on the fly.

[Anonymous]

Hope it goes ok......the Scotland trip will be a nice warm up for the Tuscany jaunt in just over six weeks   s:wink: :wink: s:wink:

[manchestermatt1986]

Hi Nic

Looking at the dyno graphs posted in the N/A thread, looks like the problem started when you had the stage 1 cams fitted. The torque curve is showing exactly what I would expect from vvti not working. It could also be a result of increased valve overlap from the cams dropping mid range torque, but I would expect that from stage 2 or 3 cams.


This has made me worry about fitting my stage 1 cams that iv purchased    s:shock: :shock: s:shock:

[Wabbitkilla]

Don't worry too much, the vvti ocv has arrived at my dealers and i'll be installing it asap, then we'll find out how the car behaves with a working vvti

[steve-m-uk]

Do you want a hand fitting it Nic? I have a vested interest in the outcome as you know Nic as mine appears to be bust too from the dyno results  s:( s:(

[Wabbitkilla]

Do you want a hand fitting it Nic? I have a vested interest in the outcome as you know Nic as mine appears to be bust too from the dyno results  s:( s:(

No worries Steve, It'll be fitted when I get home .... on a COLD engine   s:lol: :lol: s:lol:  

In case anyone is wondering .... the ocv valve is in a tight spot round the back of the engine above the alternator. When we were swapping them around while at the mappers the engines were mad hot and our fingers were pretty singed by the end of the activity.   s:scared: :scared: s:scared:    s:roll: :roll: s:roll:    s:lol: :lol: s:lol:

[steve-m-uk]

I still have blisters on three of my fingertips   s:lol: :lol: s:lol:  i found it much easier to remove the bolt on the ocv with my left hand whilst leaning forward toward the drivers side rear wheel   s:wink: :wink: s:wink:

[stevieb1973]

Did RS-Tuning do the map mate as paul down there mapped my megane 225
and he was great it would be good to get a map on the 2 from them

stevie

[Toplesscouple]

Pretty sure my VVTI isn't working and suspect it never has since we bought the car. The filter screen, below  the OCV valve, looks a right bu**er to get at. Is it a case of taking off the engine mount to gain access, does anyone know?

Waiting to hear the result of the change.  s:) s:)

[Wabbitkilla]

Well the new ocv is in, part number is 15330-22030 for those interested.
Hard to say how much of a difference it has made but I easily pulled away from a pair of standard cars tonight.
Part of the problem with this is that the vvti is very subtle in its operation.

Ok simple bit is, even the new valave doesn't move with the ignition switching one (but it did manage to magnetise and stick itself to the steel of the engine mount it was sitting on   s:lol: :lol: s:lol:  ). So there doesn't appear to be a simple test to see if it is functional, I guess we'll have to wait till the 20th when I take it back to RS-Tuning to test it on the dyno. Yes, RS are mapping it, but I'm not so impressed thus far, their initial attempt left the car hunting off throttle. I'm thinking he made a mistake when calibrating the tps. My tps has a greater range of movement than a standard one due to the modification of the throttle body to a larger bore. Still I'm sure we'll iron out these foibles on the next visit with what i hope is a working vvti.

The car does seem quicker now in lower gears, not sure if this is all in the mind so we'll see what the dyno tells us.

[PeteT]

Hard to say how much of a difference it has made but I easily pulled away from a pair of standard cars tonight.

s:oops: :oops: s:oops:  

Yes, It did shift Nic!

[steve-m-uk]

I'm sure the vvti is working now,your car pulled very well up the hill.

[FGrob]

I hope it's sorted for you Nic, I think one of the biggest problems you can have is coming from driving your daily driver into the 2, I suffer with it and makes you very unsure about the running of the car, my butt tells me the RCZ feels quicker but when I look at the speedo the 2 gets there a lot quicker and smoother. If we arrange something on the 29th you can have a drive of mine to see what you think.

Rob.

[Cap]

P1349
Condition (a) or (b) continues for after the engine is warmed up
and engine speed at 400 – 4,000 rpm :
(a) Valve timing does not change from of current valve timing
(b) Current valve timing is fixed.

If you have a problem with the VVTi, How do you explain the Absence of a Code?..  

Cap