MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: AJRFulton on April 4, 2023, 23:31

Title: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 4, 2023, 23:31
IMG_20230404_122644.jpg

The VVT has been a thorn in my side. I had my car at the tuner today and the VVT is still not engaging.

Since last year car has had

Loom salvaged from a breaker
New OEM solenoid
New ECUmaster ECU
New OEM VVT Sprocket

The only thing that stays the same are the stage 3 Piper cams.

These were cleaned, and had high pressure air blown through - appeared to have no blockages then reinstalled. The head was pretty spotless at reassembly, and reassembled as per torque/clearance values in 2zz manual.

FB_IMG_1680647092236.jpg

That was the engine prior to being bolted together.

Could the cams even prevent the VVT from working? What could be wrong with them? It is the only bit that is a constant.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Dev on April 5, 2023, 01:56
When the VVT sprocket was installed on the cam was it in the unlocked position?
There is a TSB issued that states that the VVT needs to be unlocked otherwise the lock pin can get jammed preventing the stator from moving.
Title: Re: Stage 3 cams - VVT not engaging
Post by: shiny on April 5, 2023, 05:51
Quote from: Dev on April  5, 2023, 01:56When the VVT sprocket was installed on the cam was it in the unlocked position?
There is a TSB issued that states that the VVT needs to be unlocked otherwise the lock pin can get jammed preventing the stator from moving.
I unlocked mine using compressed air.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 06:54
Quote from: Dev on April  5, 2023, 01:56When the VVT sprocket was installed on the cam was it in the unlocked position?
There is a TSB issued that states that the VVT needs to be unlocked otherwise the lock pin can get jammed preventing the stator from moving.

It was installed unlocked as per manual.

This is the 3rd engine this issue has manifested itself on, the inlet cam is the only constant.

What may have happened is the engine had been installed, oiled and turned over, then sat for 5mths after the accident. Corrosion siezed?
Title: Re: Stage 3 cams - VVT not engaging
Post by: Gaz2405 on April 5, 2023, 07:31
Does the tuner have any logs you could share.

Assuming tuner is used to emu black and switchable tables for VVti etc. (They look like a proper outfit)

Can you hear the solenoid firing in test mode ?

Have you tried different solenoids, assume occ is clear and clean etc.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 08:29
Quote from: Gaz2405 on April  5, 2023, 07:31Does the tuner have any logs you could share.

Assuming tuner is used to emu black and switchable tables for VVti etc. (They look like a proper outfit)

Can you hear the solenoid firing in test mode ?

Have you tried different solenoids, assume occ is clear and clean etc.


Solenoid is firing and duty cycle is fine.

The VVT angle isn't moving though.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Gaz2405 on April 5, 2023, 08:36
Hmm, does sound mechanical then.

Title: Re: Stage 3 cams - VVT not engaging
Post by: Call the midlife! on April 5, 2023, 08:37
Probably difficult to check but is it getting enough oil pressure to cycle it? I don't know what the stage 3 cams are designed to do but the stage 2s I had in, together with the uprated valvetrain put a lot of extra strain on the chain, especially at lower revs.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 08:55
Quote from: Call the midlife! on April  5, 2023, 08:37Probably difficult to check but is it getting enough oil pressure to cycle it? I don't know what the stage 3 cams are designed to do but the stage 2s I had in, together with the uprated valvetrain put a lot of extra strain on the chain, especially at lower revs.

In terms of oil pressure, parameters look fine, maybe even slightly high.

At idle and warm I'm about 30-35 psi at idle (1200rpm). Cold 60-80 psi. Capillary oil gauge (race tech)

This has been a pressure that worked fine before.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Call the midlife! on April 5, 2023, 09:14
Aside from all previous comments and your own suggestions it only really leaves a manufacturing flaw with the cam, maybe the alignment pin is off but you'd expect them to be assembled in a jig.
Or the vvt clutch unit is faulty, assuming you've used the same one across all three installations?
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 09:38
Quote from: Call the midlife! on April  5, 2023, 09:14Aside from all previous comments and your own suggestions it only really leaves a manufacturing flaw with the cam, maybe the alignment pin is off but you'd expect them to be assembled in a jig.
Or the vvt clutch unit is faulty, assuming you've used the same one across all three installations?

No this is a new Toyota VVT.

The piper cams have worked previously, but this is the third engine this has raised its head
Title: Re: Stage 3 cams - VVT not engaging
Post by: shnazzle on April 5, 2023, 10:37
Stupid question maybe but.. Checked for blockages on the cam and the block? Blown it out with air? No rogue dot of sealant anywhere blocking the oil?
If the cam's passages are blocked then the issue would of course transfer between blocks. 

Then there's electronics; you know the ecu is sending the signal, but can you verify that it is actually triggering the valve? I.e. the wiring is correct with any necessary pull-up/down resistors. 

Can you verify that the cam angle isn't changing? Or is it changing but the ecu isn't registering the change in angle? 

And the obvious question... Has it been set up right? 


Title: Re: Stage 3 cams - VVT not engaging
Post by: Call the midlife! on April 5, 2023, 10:59
Quote from: AJRFulton on April  5, 2023, 09:38No this is a new Toyota VVT.

The piper cams have worked previously, but this is the third engine this has raised its head
I can't remember off hand which cam carries the position sensor vanes but are they all intact, not lost a chunk or anything so the sensor is getting duff information?
A bit out there maybe but we're in clutching at straws territory almost...
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 13:21
Quote from: shnazzle on April  5, 2023, 10:37Stupid question maybe but.. Checked for blockages on the cam and the block? Blown it out with air? No rogue dot of sealant anywhere blocking the oil?
If the cam's passages are blocked then the issue would of course transfer between blocks.

Then there's electronics; you know the ecu is sending the signal, but can you verify that it is actually triggering the valve? I.e. the wiring is correct with any necessary pull-up/down resistors.

Can you verify that the cam angle isn't changing? Or is it changing but the ecu isn't registering the change in angle?

And the obvious question... Has it been set up right?




It's all pretty plug and play. I'm using the MWR 1ZZ to 2ZZ loom harness, so even less scope for an issue.

Used a stethoscope to listen for the VVT Sprocket moving, but doesn't appear to. Cam position lobes are intact.

I just cannot see where a blockage would be. There's no sealant around these systems, and again it's the 3rd different engine to have these problems.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Dev on April 5, 2023, 14:35
Quote from: AJRFulton on April  5, 2023, 06:54It was installed unlocked as per manual.

This is the 3rd engine this issue has manifested itself on, the inlet cam is the only constant.

What may have happened is the engine had been installed, oiled and turned over, then sat for 5mths after the accident. Corrosion siezed?


I doubt corrosion because the oil will still be on the internals even if the engine was sitting for many years . 

 The only thing I can think of to check is to see if the magnetic induction cam sensor is producing a clean oscillating 5V signal. It's a simple diagnosis by probing the wires attached to the cam sensor using a multimeter. It's better if you have an oscilloscope to check if its square.

 If the magnets on the end of the cam are not in perfect alignment due to a manufacturing defect it can alter the cam signal and depending on what ECU you have it cannot move the stator until it knowns the position of the cam. Aftermarket ECUs generally do not have any diagnostic functions or limp strategies. 
With the OEM ECU it will indicate a check engine light and stop the VVT. It will also fire the spark plugs multiple times to keep the car running in limp mode. If you can run the car using the OEM ECU might indicate a code that would tell you where to look. 

Title: Re: Stage 3 cams - VVT not engaging
Post by: Gaz2405 on April 5, 2023, 14:40
Have these cams ever worked successfully in any of your builds, it could be a cam issue.

Like Dev says it may not be picking up the signal.

Can the cam timing be adjusted prior to "lift"?
Title: Re: Stage 3 cams - VVT not engaging
Post by: Gaz2405 on April 5, 2023, 14:40
Do you have a standard cam you could swap in to try?
Title: Re: Stage 3 cams - VVT not engaging
Post by: shnazzle on April 5, 2023, 15:28
Quote from: AJRFulton on April  5, 2023, 13:21It's all pretty plug and play. I'm using the MWR 1ZZ to 2ZZ loom harness, so even less scope for an issue.

Used a stethoscope to listen for the VVT Sprocket moving, but doesn't appear to. Cam position lobes are intact.

I just cannot see where a blockage would be. There's no sealant around these systems, and again it's the 3rd different engine to have these problems.
Just had visions of a piece of sealant or some kind of other FM maybe finding its way into the holes in the cam.
It's my understanding that the oil flows from the block, into vvti chamber/cover, into solenoid, into cam, into sprocket.
So if there's a blockage in the cam, the oil won't make it into the sprocket to change the angle.
If there's a blockage in the ocv, then it won't make it into the cam.
If there's a blockage into the vvti cover, then it won't make it into the ocv.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 15:29
Quote from: Gaz2405 on April  5, 2023, 14:40Have these cams ever worked successfully in any of your builds, it could be a cam issue.

Like Dev says it may not be picking up the signal.

Can the cam timing be adjusted prior to "lift"?

They have worked, yes.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 5, 2023, 15:46
Quote from: shnazzle on April  5, 2023, 15:28Just had visions of a piece of sealant or some kind of other FM maybe finding its way into the holes in the cam.
It's my understanding that the oil flows from the block, into vvti chamber/cover, into solenoid, into cam, into sprocket.
So if there's a blockage in the cam, the oil won't make it into the sprocket to change the angle.
If there's a blockage in the ocv, then it won't make it into the cam.
If there's a blockage into the vvti cover, then it won't make it into the ocv.


It's possible, but I can't see it always happening.

Because I'm using run in oil it has UV dye 8n it. It looks like it's everywhere. Will need to properly look.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Carolyn on April 5, 2023, 18:17
Just because the oil gets into the hub, that doesn't mean it gets there with sufficient volume and pressure, so a partial blockage could cause the problem.  Having read the thread, it would seem either the cam sensor is faulty or the oil way in the cam is restricted.
Title: Re: Stage 3 cams - VVT not engaging
Post by: mr2garageswindon on April 6, 2023, 11:51
3 Engines same problem.. I'd be looking at ecu not operating it correctly if was same ecu for all 3 engines.
Can you reconnect a 2zz ecu easily just to test the theory?
Title: Re: Stage 3 cams - VVT not engaging
Post by: Gaz2405 on April 6, 2023, 12:46
Quote from: mr2garageswindon on April  6, 2023, 11:513 Engines same problem.. I'd be looking at ecu not operating it correctly if was same ecu for all 3 engines.
Can you reconnect a 2zz ecu easily just to test the theory?

Pretty sure the EMU black is new for this season.

I was thinking about this last night, possible wiring gremlin, but then the solenoid wouldn't fire?

The VVt actuator is new and unlocked.

I'm thinking it's got to be a tolerance issue with the cam position sensor or the cam reluctor (not sure if that's the right term)
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 6, 2023, 18:54
Quote from: mr2garageswindon on April  6, 2023, 11:513 Engines same problem.. I'd be looking at ecu not operating it correctly if was same ecu for all 3 engines.
Can you reconnect a 2zz ecu easily just to test the theory?

I don't own one.

Popped into JSpec and borrowed a ECU and a VVT Sprocket.

3 engines, the only constant is the camshaft.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Carolyn on April 6, 2023, 19:23
That makes sense.  So the oilways in the camshaft are restricted and not delivering the required pressure/flow rate.
Title: Re: Stage 3 cams - VVT not engaging
Post by: shnazzle on April 6, 2023, 20:11
It can only be that.

Did you replace the Vvt sprocket as part of the diagnosis? Or is this a new one that has worked previously for you?

Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 6, 2023, 22:10
Quote from: shnazzle on April  6, 2023, 20:11It can only be that.

Did you replace the Vvt sprocket as part of the diagnosis? Or is this a new one that has worked previously for you?



It's a brand new VVT sprocket. Only engine it's been on.
Title: Re: Stage 3 cams - VVT not engaging
Post by: shnazzle on April 6, 2023, 22:22
Quote from: AJRFulton on April  6, 2023, 22:10It's a brand new VVT sprocket. Only engine it's been on.
Ah OK. So unproven. Possible candidate as well then. Or did it also not work on other sprockets on the other 2 engines?
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 6, 2023, 23:30
Quote from: shnazzle on April  6, 2023, 22:22Ah OK. So unproven. Possible candidate as well then. Or did it also not work on other sprockets on the other 2 engines?

As said the only constant is the cams.

It has worked on the other engines, but failed also.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Alex Knight on April 6, 2023, 23:33
Tried different cams?
Title: Re: Stage 3 cams - VVT not engaging
Post by: Dev on April 7, 2023, 01:39
The smart thing to do is connect a 2ZZ ECU and then pull the code. It will clue you into the actual issue without removing anything. If there is no issue then its your stand alone ECU.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 7, 2023, 08:11
Quote from: Dev on April  7, 2023, 01:39The smart thing to do is connect a 2ZZ ECU and then pull the code. It will clue you into the actual issue without removing anything. If there is no issue then its your stand alone ECU.

Only issue is..... I don't have an OBDII port.

Anything not needed has been jettisoned on the loom.
Title: Re: Stage 3 cams - VVT not engaging
Post by: pauls0212 on April 7, 2023, 11:27
I think Carolyn has the right diagnosis in that the oilways in the cam must be slightly restricted and not delivering the correct pressure.
Title: Re: Stage 3 cams - VVT not engaging
Post by: shnazzle on April 7, 2023, 12:35
Quote from: pauls0212 on April  7, 2023, 11:27I think Carolyn has the right diagnosis in that the oilways in the cam must be slightly restricted and not delivering the correct pressure.
Never mind giving my credit to @Carolyn :) 
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 27, 2023, 11:59
Ok.

The car had been sitting with full mineral oil (Miller's Motorsport running in oil) in it for about 6mths.

I opened the rocker and there was a smell. A very biological smell.

There appears to have been, what I can only describe as clusters of algae/bacteria, growing in the engine.
(https://i.ibb.co/r3vmD25/IMG-20230427-115451.jpg) (https://ibb.co/r3vmD25)

Definitely biological whatever it is.

Can only assume this has been playing havoc with oil lines.
Title: Re: Stage 3 cams - VVT not engaging
Post by: Ardent on April 27, 2023, 12:08
 :o
Title: Re: Stage 3 cams - VVT not engaging
Post by: Carolyn on April 27, 2023, 12:11
Interesting. I've not come across that before.  How are you dealing with it?
Title: Re: Stage 3 cams - VVT not engaging
Post by: mr2garageswindon on April 27, 2023, 12:42
BG engine flush is bloody good stuff.
Used it on a 375000 mile E Class diesel, the new oil still was clean weeks after changing it. Unheard of on a diesel..
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 27, 2023, 12:56
Quote from: Carolyn on April 27, 2023, 12:11Interesting. I've not come across that before.  How are you dealing with it?


Double flushed engine with fully synthetic oil (cheap stuff). Then put in the miller's nt+.

Back at tuner tomorrow.

Put on OEM cams, OEM injectors, swapped solenoids, pulled out filter gauzes, changed VVTi sprocket, and changed cam sensor.

Also borrowed a 2ZZ ECU from JSpec, albeit for a automatic.

So work back from there.

However that configuration is worth too much time on track versus OEM (estimate about 2 seconds around Knockhill). With the spread of the field in my class being about 3 seconds.

I have blown air through things with no sign of blockage.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on April 29, 2023, 11:23
So took car a spin around the roads (joy of living 5 miles from a town).

Lift seems to be engaging and I'd say VVT is engaging - it feels right. Wheel alignment is all over place though.

Nervous about keeping OEM injectors given the failure rate I've had, and car won't be competitive with OEM cams in it (as said uprated cams are gaining 1.5-2 secs a lap).

However it's a point to work back from.
Title: Re: Stage 3 cams - VVT not engaging
Post by: AJRFulton on May 9, 2023, 17:17
Ok. Cars been on Dyno. The ECUMaster Black is a bit of kit and feels like a huge upgrade.

Cams are now engaging, lift working - cars now on the right road. I fully expected it would take a few Dyno sessions to get this running sweet.

However car isn't pulling as well as it could and got a trigger warning on the cam sensor at 7800rpm that is saying it's missing a tooth and thus artificially rev limiting me to 7800.

VVTi is also fluctuating a fair bit, and again seems to be bleeding power.

Obviously the tuner is a generalist when it comes to engines and is far from a 2ZZGE expert.

Would anyone want a look at my ECU logs to help diagnose?

My clutch was giving issues at low load (unsprung paddle clutch...... And needs replaced).

I am currently running an OEM top end, but with MWR flat valves, MWR uprated springs and MWR titanium retainers - the internet is to put stage 3 cams in again once I get the OEM set up running.

2ZZGE EMU LOG.zip

Or my Dropbox link

https://www.dropbox.com/s/52p5iglguf8y8yc/2ZZGE%20EMU%20LOG.zip?dl=0
Title: Re: Stage 3 cams - VVT not engaging
Post by: mr2garageswindon on June 19, 2023, 13:32
For some unknown reason, yesterday while daydreaming as I do at times I did think about this..
I'm sure you have but its easily overlooked..
Have you checked the lift bolts?
Could 1 be snapped?
Cheers.
Jon