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.
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.
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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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
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.