Compression test done AGAIN, UPDATE 11-21-05
11-05-2005, 08:11 PM
#12
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Originally Posted by Slows2k,Nov 5 2005, 10:02 AM
Do a leakdown test. Chances are #4's rings aren't sealing as good anymore.
Due to intake manifold design, and placement in the engine compartment #4 runs leaner and hotter than the other cylinders.
Due to intake manifold design, and placement in the engine compartment #4 runs leaner and hotter than the other cylinders.
11-05-2005, 09:34 PM
#14
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Originally Posted by fperra,Nov 5 2005, 11:11 PM
You got that right on cylinder #4. If you have the AEM EMS you can adjust the fuel in each cylinder individually, and I would highly recommend this to everyone. Read your plugs and adjust acordingly. I have an additional 7% fuel trim in #4 and 2% in #3. It took a while reading the plugs until I got them all burning about the same.
The thing is though, the #4 cylinder plug was always black compared tot he rest.
My guess is that my timing got things too hot(3 degrees total at 5000 rpm, 10psi which I fixed when I saw it).
My car has always run good so I hope its just a valve seal thingy..
Asura would scoring cause the car to run like crap or would I never know.
11-05-2005, 09:49 PM
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Depending on how bad the scoring is, you would be getting a lot of blow by which would explain some of your oil consumption and black plug.
Your leak down % will also be greater in the 'bad' cylinder. It could be due to a worn ring or a scored wall.
From my experience, if are monitoring your AFR, it will be all over the place if indeed your walls are scored.
To be safe, I would have a peek with a bore scope and check the wall condition on the driver side of the block. This is the 'upstroke' area where scoring is most likely to occur, check the entire cylinder though.
The leakdown test and bore scope are the most useful diagnosis tools to get a good idea without pulling the head.
Your leak down % will also be greater in the 'bad' cylinder. It could be due to a worn ring or a scored wall.
From my experience, if are monitoring your AFR, it will be all over the place if indeed your walls are scored.
To be safe, I would have a peek with a bore scope and check the wall condition on the driver side of the block. This is the 'upstroke' area where scoring is most likely to occur, check the entire cylinder though.
The leakdown test and bore scope are the most useful diagnosis tools to get a good idea without pulling the head.
11-05-2005, 10:07 PM
#16
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Originally Posted by Asura,Nov 6 2005, 12:49 AM
Depending on how bad the scoring is, you would be getting a lot of blow by which would explain some of your oil consumption and black plug.
Your leak down % will also be greater in the 'bad' cylinder. It could be due to a worn ring or a scored wall.
From my experience, if are monitoring your AFR, it will be all over the place if indeed your walls are scored.
To be safe, I would have a peek with a bore scope and check the wall condition on the driver side of the block. This is the 'upstroke' area where scoring is most likely to occur, check the entire cylinder though.
The leakdown test and bore scope are the most useful diagnosis tools to get a good idea without pulling the head.
Your leak down % will also be greater in the 'bad' cylinder. It could be due to a worn ring or a scored wall.
From my experience, if are monitoring your AFR, it will be all over the place if indeed your walls are scored.
To be safe, I would have a peek with a bore scope and check the wall condition on the driver side of the block. This is the 'upstroke' area where scoring is most likely to occur, check the entire cylinder though.
The leakdown test and bore scope are the most useful diagnosis tools to get a good idea without pulling the head.
My a/f is always the same and is never all over the place.
When I first get on it the car does let out a puff of smoke but none after that.
I will keep this post updated.
11-09-2005, 09:12 PM
#17
Thread Starter
I was reading the manual and realized that the max variance is 28psi, not 15 like I had thought.
I still have an appointment for a leak down test.
So those who might still be interested I will post the results.
I still have an appointment for a leak down test.
So those who might still be interested I will post the results.
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