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Discussion Starter · #1 ·
Does anyone know how to bybass the temp sensor on the cyl head that activates the knock sensor. This ativates the knock sonsor when the engine is over reved, and is not up the temp.
 

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Color me Gone
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27,333 Posts
vroddave I'm not sure what your trying to do but the ect sensor is a varying voltage between 1-5 volts and is used to calculate fuel mixture according to engine temp. When you say disable it you will change your fuel map all together. If your looking to change the rev limiter I suggest an RT as it will allow you to change the Rev limit manually.
 

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SNAFU
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Dave, there's no knock sensor on the V-Rod motor and modifying the signal to the ect will only change your fuel map like Max said. Knock sensing is done via the spark plugs using ion sensing technology. Essentually it detects fluctuations in the current flow to the plugs and uses that to determine when detonation is occuring.

It looks like you want to disable the built in 8K rev limit before the engine gets to proper operating temperature. I suppose faking this signal would accomplish your wish along with probably burning a valve or chipping off a piece of the piston due to detonation. Then again, that's just my opinion.
 

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Discussion Starter · #4 ·
mjw930 and Max thanks for your speedy reply. my rev limitor is set at 9300 via the race tuner. For some reason it sometimes comes on early.I think around 7to8000. The engine has been warmed up. And I know it's not too cool to rev to 9000 where my shift point is set. Just trying to find out whats going on. thanks for any info on this matter
 

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Color me Gone
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vroddave, it may be a failing rear coil rather then the rev limiter. If I were you I would pull the coil and check the spring that goes between the coil and the plug top. This is just a guess but the first thing I would check as a coil failing will give similar results as the rev limiter.
 

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Jamie
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VRodDave,

The max engine speed varies with engine temperature to prevent premature wear or damage to the engine at cold engine temps.

Disabling the ECT sensor from reading the correct engine coolant temp wil change the fueling requirements drastically and will force the engine to run very lean/misfire under cold starts and running conditions.

We have to wait for this as well in the races, otherwise we will get an early "rev limit" because the engine was not up to temp.

Max and mjw930 are pretty correct on the definitions of the components, and a grounding of the coil could be happening. A cracked insulator in the plug will also do this, so try replacing them as well.
 

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Discussion Starter · #8 ·
Jamie we may have found the problem. I have changed to a kill system that opens the circuit rather than grounding it. I also found a toggle switch that may have been giving us some trouble. I was using it to switch between button shifting and auto-shift. I just took it off. Everything seems to be working well now. I race it fri. night at the SanAntonio streetriders shootout. Guess I'll find out for sure then.
 
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