Constant Knock Voltage on S300

volky_r · Post by **volky_r** » Mon Sep 21, 2009 11:46 am

Hi,

After 2-3 min. of easy regular driving the S300 will display .1V from the knock sensor constant and woun't go away until the engine is turn off, it will not go to 0V even if I leave it on idle after it comes up.

If I turn the car on and leave it at idle it will stay at 0V, it will not change to .1V until it is driven. I have lower the timing, change the plugs to NGK number 9's and I'm running a mix of 100oct and 110oct fuel. I also replaced the knock sensor and no change.

What could be the reason? Could it be a false reading?

Any help would be greatly apreciated!!

Engine setup:
GSR block with Golde Eagle sleeves bored to 85.5mm
85.5mm high compression Wiseco pistons (13.5:1)
Carillo rods
Gsr crank
B16 head shaved (don't know how much)
Crower stage 2 cams
330cc mazda injectors at 50psi/60psi WOT
Complete assembly was balanced

kinetics · Post by **kinetics** » Mon Sep 21, 2009 11:57 am

I'm going to shoot a wild guess at there actually being knock.
The CEL won't ever clear until you shut the car off, or clear it with the little button in SManager.

How do AFR's look?

Post by **Spunkster** » Mon Sep 21, 2009 12:13 pm

Since you have forged pistons then you may be getting piston slap that is being picked up as knock. Most people with aftermarket pistons have too disable the knock sensor.

volky_r · Post by **volky_r** » Wed Sep 23, 2009 11:19 am

A/F is good, around 14.7 without load.

I clear the code but it comes wright back in a few seconds.

SO it could be because the diferent internals?

Thanks

Post by **Spunkster** » Wed Sep 23, 2009 11:45 am

What ECU are you using?