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1992 TBI 16146299 code 99 Lo3 305 Vss vs Knock

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Old May 9, 2011 | 10:40 AM
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1992 TBI 16146299 code 99 Lo3 305 Vss vs Knock

Hi all. I'm modifying the subject ecm code for a marine engine, going in my old boat.

I've read that the vss can be eliminated successfully by grounding the park/neutral input, to make the ecm believe it's in neutral all the time. This makes the vss input ignored, and blocks the egr activation.

I thought, how simple and good. Then I read about how how the knock sensor is enabled above 10mph. I definately want the knock sensor active!

If I uncheck the vss flag in the code does it make the above moot? I can burn my own stuff (I'm using an adapter, an ostrich, and tunerpro).

Thanks,

Chay
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Old May 9, 2011 | 01:46 PM
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: 1992 TBI 16146299 code 99 Lo3 305 Vss vs Knock

Most of the time the knock system is active when either the MPH is above a threshold or the RPM is above a threshold.

Can test this by raising the RPM and whacking the block with a wooden stick (broom handle). The RPM should dip as the spark is pulled. Note that the engine needs to be up to temperature for this to work.

RBob.
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Old May 9, 2011 | 01:52 PM
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Re: 1992 TBI 16146299 code 99 Lo3 305 Vss vs Knock

Thanks for the reply. It's conforting to know there is a rpm enable too. Any idea when it kicks in?


Thanks,

Chay
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Old May 10, 2011 | 07:31 AM
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From: Chasing Electrons
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Re: 1992 TBI 16146299 code 99 Lo3 305 Vss vs Knock

Originally Posted by marinetbi
Thanks for the reply. It's conforting to know there is a rpm enable too. Any idea when it kicks in?


Thanks,

Chay
It depends upon the calibration, typically right above idle speed, so maybe 700 RPM.

Note that EGR can be active while not moving, again, it depends upon the calibration. Best bet is to set the EGR CTS enable threshold to 150* C.

RBob.
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Old May 10, 2011 | 11:06 AM
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Re: 1992 TBI 16146299 code 99 Lo3 305 Vss vs Knock

Thanks. I looked in the bin but didn't see any listing for the setting for knock enables.

I did up the activation temp to max on the egr to block it.

Thanks again,

Chay
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