Curly Intake Camshaft/AVCS Question
31 August 2006, 10:44 AM
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Curly Intake Camshaft/AVCS Question
Trying to troubleshoot an AVCS not working problem with new AVCS Kelford Cams that have been installed. Solenoid/OCV has been tested OK, signal from the ECU tested OK and oil pressure to the OCV is good.
The diagram below shows a side on view of the intake cam sprocket, the AVCS system and part of the intake camshaft (shaded purple).
My question relates to the bolt that holds in the cam sprocket, which I have highlighted in red. This bolt has a cavity in the middle as indicated in the diagram. Inspecting the factory camshafts, the camshafts also have a cavity that extends all the way to the middle of the camshaft where there is a hole in the camshaft, where I presume oil can exit the camshaft.
My question is, does the cavity in the bolt extend through to the cavity in the camshaft? Or is there a wall or something at the end of the bolt that stops the cavity extending through to the camshaft cavity? My guess is with the former, otherwise why would they put a cavity in there in the first place.
This is important as putting a wire down the bolt cavity on the installed Kelford camshaft only reaches about as far as the end of the bolt - nowhere near the middle of the camshaft which I would expect with the factory camshaft. Also air blown down the cavity is forced back out the cavity - it is not exiting into the oil system. This could mean the camshaft cavity has not been ground in the Kelford camshaft, stopping oil pressure from being released from the AVCS system, effectively stopping it from working.
Any help would be much appreciated...
The diagram below shows a side on view of the intake cam sprocket, the AVCS system and part of the intake camshaft (shaded purple).
My question relates to the bolt that holds in the cam sprocket, which I have highlighted in red. This bolt has a cavity in the middle as indicated in the diagram. Inspecting the factory camshafts, the camshafts also have a cavity that extends all the way to the middle of the camshaft where there is a hole in the camshaft, where I presume oil can exit the camshaft.
My question is, does the cavity in the bolt extend through to the cavity in the camshaft? Or is there a wall or something at the end of the bolt that stops the cavity extending through to the camshaft cavity? My guess is with the former, otherwise why would they put a cavity in there in the first place.
This is important as putting a wire down the bolt cavity on the installed Kelford camshaft only reaches about as far as the end of the bolt - nowhere near the middle of the camshaft which I would expect with the factory camshaft. Also air blown down the cavity is forced back out the cavity - it is not exiting into the oil system. This could mean the camshaft cavity has not been ground in the Kelford camshaft, stopping oil pressure from being released from the AVCS system, effectively stopping it from working.
Any help would be much appreciated...
31 August 2006, 10:52 AM
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I thought Kelford only did the AVCS cams for the 2.5 STI engine? If this is the case they will have the wrong pickups for use the the JDM sensors and ECU.
Iain
Iain
31 August 2006, 11:16 AM
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Originally Posted by LitchfieldImports
I thought Kelford only did the AVCS cams for the 2.5 STI engine? If this is the case they will have the wrong pickups for use the the JDM sensors and ECU.
Iain
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31 August 2006, 01:12 PM
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The drawing shows the oil return path as back out of the AVCS valve not via the camshaft so it should make no diff.
How do you know the AVCS is not working ?
As I understand it, the AVCS advances by increasing the oil pressure to advance the angle but needs feedback to tell it what the angle is, it then cycles the AVCS valve to maintain pressure. If your sensors are not working, or the sprocket can't rotate in relation to the cam, then it won't work ?
Is the AVCS actuator assembled correctly, is it free to turn ?
How do you know the AVCS is not working ?
As I understand it, the AVCS advances by increasing the oil pressure to advance the angle but needs feedback to tell it what the angle is, it then cycles the AVCS valve to maintain pressure. If your sensors are not working, or the sprocket can't rotate in relation to the cam, then it won't work ?
Is the AVCS actuator assembled correctly, is it free to turn ?
Last edited by Gary C; 31 August 2006 at 01:22 PM.
01 September 2006, 08:08 AM
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Originally Posted by Gary C
The drawing shows the oil return path as back out of the AVCS valve not via the camshaft so it should make no diff.
How do you know the AVCS is not working ?
As I understand it, the AVCS advances by increasing the oil pressure to advance the angle but needs feedback to tell it what the angle is, it then cycles the AVCS valve to maintain pressure. If your sensors are not working, or the sprocket can't rotate in relation to the cam, then it won't work ?
Is the AVCS actuator assembled correctly, is it free to turn ?
How do you know the AVCS is not working ?
As I understand it, the AVCS advances by increasing the oil pressure to advance the angle but needs feedback to tell it what the angle is, it then cycles the AVCS valve to maintain pressure. If your sensors are not working, or the sprocket can't rotate in relation to the cam, then it won't work ?
Is the AVCS actuator assembled correctly, is it free to turn ?
I'm not sure what the camshaft passage does, but it is clearly there for removing oil pressure into the rocker covers, and is only on the intake camshafts. Hence it likely is a factor in the AVCS working correctly.
The cams are off on Monday now so we'll hopefully soon find out the issue.
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06 May 2007, 02:01 AM
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If you're running AVCS, the oil hole is critical.
If it's not running through, you either have the wrong cams (most likely) or the cams haven't been machined correctly (highly unlikely).
Who supplied you the cams, are they unable to assist you?
If it's not running through, you either have the wrong cams (most likely) or the cams haven't been machined correctly (highly unlikely).
Who supplied you the cams, are they unable to assist you?
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