Cam angle jitters and 'no sync'

[busher06]

LY7 engine MS3/3X running v1.3.0. Had full sync on v1.2.4 but angle sensing issues on one inlet cam and one exhaust cam on either bank, so loaded v 1.3.0 and still had the same issues. Did a reset of the R11/R32 proceedure, no change. The msl is too big to post. I will try to get a shorter one soon. Just the msq for now. The angle jitters have me most concerned.
Need help from the collective wisdom as I have no clue as to what the next step should be.
Thanks all.

[busher06]

Cam and crank composite log

[Matt Cramer]

Any chance the cam signal is triggering on the wrong edge?

[busher06]

I am not clear on which cam signal you refer to. In the VVT menu I logged both all rising and all falling. In Ignition options I left the cam poll level as low. Should I try altering this poll level to high? Using all stock OEM hardware.
Many thanks for the response.

[S.Bretz]

That's odd that JUST cam angle #1 is way off from the other 3 cams.
Is the senor seated all the way?

Have you tried to swap the senor with ...say #3? to see if the issue moves?

Try unplugging the actuator. With It not supplying that cam with oil pressure, it should stay locked at the standard starting position. If the angle is still all over the place after swapping the pick up and unplugging the actuator....well, start questioning everything else.

Do you have the control going the correct direction (adv/ret) when the actuator is pulsed?
I'm thinking that it is something to do with a pick up signal since #1 is commanded to zero duty cycle but the angle is all over the place.

Try unplugging the actuator. With It not supplying that cam with oil pressure, it should stay locked at the standard starting position.

[busher06]

Unplugging the sensor connectors only changes the numbers not the the degree of fluctuation or the lack thereof in the #4 cam. Roll on Tuesday to see if we can effect some meaningful changes.
Thanks for the interest.
regards

[busher06]

During the test process, the actuators seemed to move in a controlled manner with duty cycle. After I do Matt Cramers suggestion, then I will try the 1.3.1 Beta code and post all logs.Fingers crossed because I have no science to go on.

[S.Bretz]

No no no no no... don't unplug the sensor...unplug the ACTUATOR.


I would first try swapping the angle sensor and see if the issue follows the sensor. If it does then you know the issue is the sensor.
If the problem stays on cam 1, then unplug the actuator. The actuator opens to supply oil pressure to the cam phaser...if no oil pressure is present then the phaser stays locked in at one angle ( unplugging the actuator should prevent oil pressure to the phaser)....so it should then read a consistent angle.

If that does not work then its not the sensor, the actuator or a mechanical issue with the phase. ... then you know its electrical.

[busher06]

Good thinking man,
Revised 'to do list' for tomorrow. Will let you know how it goes.

[S.Bretz]

I came across a bulletin today about VVT actuators on a 2.5L weak-o-tec... it sounded a lot like what you have going on with that one came.

The cam actuators are closed immediately when the engine is shut off. The oil pressure will stay between the actuator and the phaser and won't bleed down to allow the phaser to lock back into the parked position...so when the engine is started a few hours later, the engine makes a bunch of noise from the cams bouncing back and forth from max retard to max advance.

Again, its not the same engine, but I would imagine the cam angles would record the way your #1 angle recorded in the data log. If there is pressure trapped in in there, you should be able to pull the actuator out and then slide it back it...it should then eleviate that issue (if its happening).

In the case of the 2.5L, there was an ECM recalibration... it did not specify what was changed, but I would imagine the actuators get pulsed after the engine stops to blow the oil pressure off.

[busher06]

Ran the cam angle test again yesterday and all the cams moved but cam 4 angle gauge is giving strange response. I am also seeing "no rev limit" and "half sync" and sync loss reason 0 and 2 at random ( at least I don't understand why). Will post a smaller msl later. Deeply confused. Need some help.

[jsmcortina]

VVT isn't enabled in that MSQ.
The composite log looks ok.
I can't comment further without a datalog and correct MSQ.

James

[busher06]

Just ran through some more 'Things to check' and nothing seemed wrong but there is something that I am not seeing or understanding.Sorry to have posted the wrong msq. James, but the level of confusion......

[jsmcortina]

Can you post a regular datalog too. The SDcard datalogs are great for use on the track or capturing high-speed data, but I need to access some fields that you haven't enabled. If you also turn on "PORT STATUS" in Project Properties, the datalog will capture the input i/o ports.

The datalog shows that VVT1,2,3 are doing something, but VVT4 appears stuck on zero. Is there a signal from cam4?
EDIT: Also, you may want to try setting the "check at tooth#" on the ignition page to 2.

James

[busher06]

Thanks for the tips.It did not start with "2" but started with "0". Hope the datalogs are long enough. Will continue trying to get started with "2" selected. During the cam test, all 4 cams moved enough to stall the engine from high idle @ 40% and 60% duty.

[busher06]

Made a few tries with vvt rising edge and falling edge and changing from tooth 0 to 2 after start up

[S.Bretz]

Hmm...#1 still looks like its bouning all over the place (50 degree movement). I really hope you get this sorted...I'm sure its something silly messing with you.

What's wrong with the map reading? The datalog on my computer shows it steady at 100.3 kpa even when its running.

[busher06]

I was playing around with rising and falling edge settings so the angles gauges were going crazy.Still can't get cam 4 gauge to behave but the cam does move with dc.Running 100% TPS so baro not connected.Trying one thing at a time.Pondering about 1.3.1 still.

[jsmcortina]

The composite log you posted showed that the capture edge for cam1 was correct at that time, leave it alone.

When changing the poll level tooth# to 2, you may change the captured phase (as noted in the tooltip.) If this is the case, add 360 deg to the main tooth#1 angle.

The purpose of capturing on tooth#2 instead of tooth#0 is because the composite log shows the tooth edge to be very close to #0 - it is possible it is unreliable at that point and could be giving you the intermittent half-sync.

James

[busher06]

Thank you James. Will make the adjustments and report the results.