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How to Bypass the knock sensor?

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Old 05-31-2001, 07:17 AM
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How to Bypass the knock sensor?

Does anybody know how?

Please let me know.

Thanks

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Old 05-31-2001, 09:47 AM
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Don't do it, you might lose a piston.

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Old 05-31-2001, 10:15 AM
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The best thing to do is control it properly within the eprom. I agree with Kyle and do not beleive you should disable it, you are asking for more problems that its worth.
Old 05-31-2001, 11:25 AM
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Boo you guys, really, BOOOOO!

Without a scanner and the ability to see what is really going on, bypassing the KS can be a good way to eliminate knock, whether false or true from your tuning equation.

Bypassing is gravy...3.9K ohm resistor to ground in place of the KS.
...ed

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Old 05-31-2001, 03:11 PM
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what would happen if you just diconected knock sensor and did not put in the 3.9k resistor? do you need this resistor?
Old 05-31-2001, 04:08 PM
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I agree with Ed. Disconnect it. In my old TurboCoupe, we use to do this all the time. Even with 20psi of boost, just run real good fuel. Everything will stay together.



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Old 05-31-2001, 04:18 PM
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<font face="Verdana, Arial" size="2">Originally posted by WHITE87GTA:
what would happen if you just diconected knock sensor and did not put in the 3.9k resistor? do you need this resistor?</font>
My 92 will throw a code within 10 seconds if there is no KS or resistor taking it's place. Not sure how fast the diagnostics kick in on MAF cars.
Also, i wanted to add to my earlier post, saying you really shouldn't do this as a long term fix. Use it as a tuning aid so you can hear knock, rather than have the computer take timing out before you even know you're pinging. Or if you find out you run a lot stronger with it bypassed you know you have an issue with false knock stealing your timing.
...ed
Old 05-31-2001, 04:24 PM
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supposedly the factory program takes out 2-4 degrees of timing when the car shifts from 1st to 2nd on an auto i read an article a while back it said to splice a 3ohm resistor into the circuit and hook it back up normal
Old 05-31-2001, 07:18 PM
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I drove my '86 around when I first got it and never had a problem. After putting about 4k mile on it, I noticed it disconnected, and plugged it back in. Never threw a code. Just make sure you run cool, set the timing before and run 93+ octane only. make sure there's no chance to detonate. Then look into disconnecting it...but then, you wouldn't need to, so it would be better to leave it in as a safety measure...I'd just do the prom work.
Old 05-31-2001, 09:12 PM
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I've heard that disconnecting the sensor without installing the resistor will put the ECM in limp home mode when the coolant temp goes above a certain temperature...if that's true, then I would at least put the resistor in to "trick" the ECM. Can anyone else verify this?

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Old 05-31-2001, 11:00 PM
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<font face="Verdana, Arial" size="2">Originally posted by DANIELEK:
Does anybody know how?
Please let me know.
Thanks
</font>
In the chip you have to reset a flag.

Parameters for setting the error code vary some calibration to calibration. There is always a min coolant temp setting.

Some programs run a K/S test when you first turn the key on, and then again at over 3/4 throttle.

Some codes, won't allow Power enrichment if the system fails the K/S test.

If you want to disable it correctly, you need to read up on chip burning.
Old 06-01-2001, 12:07 AM
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Grumpy, sounds like another candidate for a FAQ.
Old 06-01-2001, 01:31 AM
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Hey Glenn, I think you need to pull your weight around here. I mean over 6000 posts is really not going to cut it. ROFL j/k......

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Old 06-02-2001, 09:23 PM
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machine man told me guy forgot to put his knock sensor in in a block he did. slapped smiley faces in the cylinder walls. thats just what he told me though
Old 06-03-2001, 01:43 AM
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I woldn't reccomend removing it either, unless you know how to recognize detonation (including when you can't hear it).

You could just desensitize it instead of completely removing it.


Remove it,

clean the theads thoroughly,

apply several wraps of teflon tape to the threads,

Reinstall with just enough torque to seal it from leaking coolant.

Plug the connector back in and you're done

You'll have less protection but still some, and you won't have to worry about the ECM getting ticked off at you.

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