S300 knock sensor goes full retard..

s300 and SManager software questions & answers
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BCMotors
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S300 knock sensor goes full retard..

Post by BCMotors » Fri Apr 26, 2019 3:49 pm

After searching this forum for "knock" and reading the 75 stupidest questions ever created; I still have an issue..

I'm running S300 installed in a P30 ecu. The knock sensor reads full knock, all the time. (Everything else works GREAT, God bless hondata)

At first, in my h22 engine, I wrote it off to "the b16 knock board is probably looking for a different frequency, and reading false knock." Disabled it in settings, good to go.

Then I ran it in 2 customers' b18c motors, same issue. Full knock level, full 10° retard.

So.. How do I get the p30 knock sensor circuit to work, OR, is there a better way to tune ignition timing?

Thanks!
B

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Spunkster
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Re: S300 knock sensor goes full retard..

Post by Spunkster » Fri Apr 26, 2019 4:28 pm

You may just have a faulty knock board if it is reading knock at all times.

skaterguy1986
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Re: S300 knock sensor goes full retard..

Post by skaterguy1986 » Fri Apr 26, 2019 6:03 pm

The old Honda ecu knock boards are configured SPECIFICALLY for the engine in which they ran from the factory so even if this ECU was working right on a B16A engine it will not read knock correctly on a H22A. If you wanted to run a closed loop knock it'd be best to find a P13 ECU and attempt to take the knock board from it and attach it to the P30 board.

As far as tuning ignition timing goes it would probably be best to get some knock ears rather than relying solely on the engines knock sensor.

BCMotors
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Re: S300 knock sensor goes full retard..

Post by BCMotors » Sun Apr 28, 2019 6:32 am

Dammit spunkster, you're supposed to tell me I'm high and missed a step in the install. Cut 1 resistor and everything's good to go.. But you're probably right, that corner of the ecu case is a bit crusty. 2 pins of the ribbon have green corrosion.

@skaterguy those knock ears look sweet, never heard of them before.

The first thing I learned in college is "don't believe everything you read." But, I read in another forum; you can change a few resistors on the knock board to calibrate it for different engines. And those resistors are allegedly the same for US p30 and JDM p13.

skaterguy1986
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Re: S300 knock sensor goes full retard..

Post by skaterguy1986 » Mon Apr 29, 2019 10:41 am

Ah well I don't have the 2 boards in front of me to compare but I do know that each board is calibrated to the engine. Taking the board from the P13 would be the most sure fire way to know that it is picking up knock and not any normal mechanical noise the engine creates.

I want to try to find a P13 that is not functioning for cheap as long as it has a working knock board to see if I can add it to the P28 I have running my Prelude. The header exists on the P28 so it should be possible.

Maybe S300 v4 will support more modern knock sensors in the future with custom noise filtering like a lot of the stand alone units do.

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Re: S300 knock sensor goes full retard..

Post by Spunkster » Mon Apr 29, 2019 11:07 am

You cannot just add a knock board to a P28. There is additional circuitry that must also be added and we do not have that info.

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