cam and crank sync with vvt

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cam and crank sync with vvt

Postby scopedog » Mon Jan 16, 2017 3:38 pm

hi can anyone confirm if its possible to check cam and crank sync if the vehicle is fitted with vvt or similar?


thanks in advance
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Re: cam and crank sync with vvt

Postby STC » Tue Jan 17, 2017 12:35 pm

Yes you can, the scope will show you where the Cam(s) are in relation to the Crank. You may want to add an amp clamp to the VVT Solenoids so you can see all the variables on the screen.

Of course you will need a "Known Good" or a Technical Document to compare the capture with for Synchronisation.
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Re: cam and crank sync with vvt

Postby scopedog » Thu Jan 19, 2017 10:01 am

Thanks for the reply much appreciated
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Re: cam and crank sync with vvt

Postby Autonerdz » Fri Jan 20, 2017 7:06 pm

Not going to go into all the details of why here but do be aware that reference captures of known good CKP/CMP from VVT engines may not look like yours. This does not necessarily mean there are any problems.
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Re: cam and crank sync with vvt

Postby victor2k » Fri Jan 20, 2017 8:28 pm

scopedog wrote:hi can anyone confirm if its possible to check cam and crank sync if the vehicle is fitted with vvt or similar?


thanks in advance

Hello,
You can check cam vs crank sync but you must know how VVT/VTEC/Vanos work on your engine:at cold/hot engine,at starting,idle,partial or full load(like VVT/Valvematic in the attached images).
Regards
Attachments
vvt.png
Last edited by victor2k on Sun Jan 22, 2017 10:08 am, edited 5 times in total.
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Re: cam and crank sync with vvt

Postby STC » Sat Jan 21, 2017 7:12 am

Hi Victor

You can check cam vs crank sync but you must know how VVT work on your engine: at cold/hot engine, at starting, idle, partial or full load.


I am thinking that these systems are so versatile now that there would be all the variables you have listed above and more .... making it impossible, or at least difficult to get 2 engines at the same condition. With 2 or 4 variable cams it just adds to the difficulty.

The only way I can think of making a good comparison with a scope would be to take several captures.
The most useful would be
1. With the VVT solenoids disconnected, at cranking, fuel cut on both cars before taking the captures That would confirm Basic Mechanical Timing.
2. Idling Cold at a fixed known Temperature
3. Idling Hot at a fixed known Temperature
From there any further issues could be addressed with the knowledge that the belt or chain is correct.

I write that from a theoretical / educated guess point of view rather than actual experience.
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Re: cam and crank sync with vvt

Postby Dave Hill » Sun Jan 22, 2017 12:23 am

If you disable the dephaser / vanos (or whatever your preferred terminology is) control solenoid, then the cam or cams will assume a default position, from which it should be possible to take a capture & compare it to a known good one, from a motor that has also been placed in default mode.

Trying to decipher a live & active variable cam alignment would be like knitting fog. :shock:
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