Jumped timing chain ID with a scope

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Re: Jumped timing chain ID with a scope

Postby ScannerDanner » Mon Feb 27, 2012 9:12 pm

Hey guys, I took some more captures of this car today and I plugged in some numbers that Mick from iATN shared with me. I think there are some variables with the CKP sensor as far as cursor placement, but I haven't done enough of this yet to contribute any more right now.
I did pull the valve cover off today to expose the chain and it is super sloppy! So this was a good call. I will take some digital photos for you guys tomorrow.
So check out the pics. I will include the two pico files as well. One during idle the other during cranking.
The image files 1-7 are during idle and 8-11 are during cranking
I am still not 100% sure on my cursor placement and you will see in images 6 and 7 (zoomed in pics at idle) that cursor placement changes everything. You will also notice the valve timing is different during a crank. I believe this is because the chain is so sloppy.
2006 Chevy Malibu Ecotec Timing Problems_1.png
Idle
2006 Chevy Malibu Ecotec Timing Problems_2.png
Idle
2006 Chevy Malibu Ecotec Timing Problems_3.png
Idle
2006 Chevy Malibu Ecotec Timing Problems_4.png
Idle
2006 Chevy Malibu Ecotec Timing Problems_5.png
Idle
2006 Chevy Malibu Ecotec Timing Problems_6.png
Idle zoomed
2006 Chevy Malibu Ecotec Timing Problems_7.png
Idle zoomed
2006 Chevy Malibu Ecotec Timing Problems_8.png
Cranking
2006 Chevy Malibu Ecotec Timing Problems_9.png
Cranking
2006 Chevy Malibu Ecotec Timing Problems_10.png
Cranking
2006 Chevy Malibu Ecotec Timing Problems_11.png
Cranking
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Re: Jumped timing chain ID with a scope

Postby ScannerDanner » Mon Feb 27, 2012 9:24 pm

a.psdata
Idle
(1.74 MiB) Downloaded 225 times
Here is the original pico file at idle
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Re: Jumped timing chain ID with a scope

Postby Martyn » Wed Feb 29, 2012 8:59 am

I have added the pictures to the earlier post :)
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Re: Jumped timing chain ID with a scope

Postby ScannerDanner » Wed Feb 29, 2012 9:21 pm

Ok I don't know if anyone is still following thread but here it goes anyway. I believe that bad information is worse than no information at all. One of the things that I always try to do when taught something new is to test the theory and learn all of the variables. I believe that my previous captures where I used the CKP sensor to ID TDC and BDC in the waveforms was wrong or I am just too new to this and placed my EVO and IVC cursors in the wrong place. It was a jumped chain for sure but the numbers didn't match up to what I saw with the chain. The intake chain was a full two links off (4 teeth) and the exhaust was a full link off (2 teeth). In the pictures I posted the exhaust valve timing seemed to be more off than the intake.
So today I took some known good captures of a 2004 ECOTECH 2.2 engine (same engine code as the 2006 with the jumped chain). I applied the same measurements to see if we could in fact rely on the CKP signal to determine TDC. What I found was that we either cannot, or I placed my cursors for valve timing in the wrong place. I just didn't want anyone to use this method if it doesn't work. Here are the known good engine pics. You will find that these numbers are different from the jumped chain but still not to spec using this method.
2004 Chevy Classic Known Good_1.png
Cranking
2004 Chevy Classic Known Good_2.png
Cranking
2004 Chevy Classic Known Good_3.png
Cranking
2004 Chevy Classic Known Good_4.png
Cranking
2004 Chevy Classic Known Good_5.png
IDLE
2004 Chevy Classic Known Good_6.png
IDLE
2004 Chevy Classic Known Good_7.png
IDLE


Here are the original Pico files
a.psdata
Cranking
(4.46 MiB) Downloaded 199 times

b.psdata
Cranking
(4.99 MiB) Downloaded 222 times
a.psdata
Running
(4.12 MiB) Downloaded 219 times
b.psdata
Running
(4.48 MiB) Downloaded 221 times
c.psdata
Running
(4.94 MiB) Downloaded 217 times
d.psdata
Running
(3.74 MiB) Downloaded 222 times
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Re: Jumped timing chain ID with a scope

Postby Robski » Wed Feb 29, 2012 10:41 pm

still following .............
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Re: Jumped timing chain ID with a scope

Postby Mick » Thu Mar 01, 2012 4:10 pm

I had to cut the above to be able to post this
ScannerDanner wrote:I just didn't want any one to use this method if it doesn't work.

So after your second vehicle one bad and one known good you are now the authority on pressure waves pretty good going sport.

ScannerDanner wrote:Here are the known good engine pics.

If only I could master posting images to this forum


ScannerDanner wrote:You will find that these numbers are different from the jumped chain but still not to spec using this method.

That is absolutely wrong the intake of the known good waves intake closing lines up perfectly at 56* ABDC to the crank pulse.

comparison wave intake side
comparison wave intake side.gif
comparison wave intake side


comparison wave exhaust side
comparison wave exhaust side.gif
comparison wave exhaust side
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Re: Jumped timing chain ID with a scope

Postby Martyn » Fri Mar 02, 2012 9:21 am

Mick,
Did you get my message about posting ?

Regards,
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Re: Jumped timing chain ID with a scope

Postby Mick » Fri Mar 02, 2012 2:28 pm

Martyn wrote:Mick,
Did you get my message about posting ?

Regards,


Yes thank you Martyn.
It looks as if I can add images now but I will try to place them into the specific area like you did next time.
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Re: Jumped timing chain ID with a scope

Postby ScannerDanner » Fri Mar 02, 2012 2:59 pm

Mick wrote:I had to cut the above to be able to post this
ScannerDanner wrote:I just didn't want any one to use this method if it doesn't work.

So after your second vehicle one bad and one known good you are now the authority on pressure waves pretty good going sport.

ScannerDanner wrote:Here are the known good engine pics.

If only I could master posting images to this forum


ScannerDanner wrote:You will find that these numbers are different from the jumped chain but still not to spec using this method.

That is absolutely wrong the intake of the known good waves intake closing lines up perfectly at 56* ABDC to the crank pulse.

comparison wave intake side
comparison wave intake side.gif


comparison wave exhaust side
comparison wave exhaust side.gif



Mick, please forgive me as I did not mean to offend you. You have been great at responding to my questions and giving me direction. What I posted on this forum about "bad information", I meant the information that I provided may be bad. I did not mean to imply that your information is bad. While I still have my doubts, I appreciate your contribution to this and truly am just looking for some clarification. When I didn't here from you about whether or not I placed my cursors in the correct location on the original jumped chain pictures that I did (using your formula), I assumed they were correct. So when I applied the same placement of the cursors on the known good engine and found the numbers to be all wrong, this is where my doubts are coming from.
Again I apologize to this board for placing this thread into two different forums as I believe I have created a monster. I was just trying to update this forum as to my findings and my doubts so as to not lead anyone down the wrong path.
Mick in my description I did say that either this method doesn't work OR my cursors where placed in the wrong place.
I am listening to where I went wrong if you are still willing to share.
Either way thanks Mick
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Re: Jumped timing chain ID with a scope

Postby Mick » Fri Mar 02, 2012 7:06 pm

ScannerDanner wrote:Mick, please forgive me as I did not mean to offend you. You have been great at responding to my questions and giving me direction. What I posted on this forum about "bad information", I meant the information that I provided may be bad. I did not mean to imply that your information is bad. While I still have my doubts, I appreciate your contribution to this and truly am just looking for some clarification. When I didn't here from you about whether or not I placed my cursors in the correct location on the original jumped chain pictures that I did (using your formula), I assumed they were correct. So when I applied the same placement of the cursors on the known good engine and found the numbers to be all wrong, this is where my doubts are coming from.
Either way thanks Mick


I hope you clear this up on iATN as well.

Over at Autonerdz, I, along with others have captured digital and analog crank sensors, the ones with multiple pulses allow you to measure in more detail.
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