Rev limiter output

[David Withers]

I have been trying to build a rev limiter using the MJLJ rev limiter output. With a 2k resistor to +12v from the output I get the following voltage readings

Ignition on 12V
Cranking 0V Coils disconnected
Running below rpm limit 12V
Running above limit 0V

The problem is that the output goes low whilst the engine is cranking, before it starts. This prevents the engine starting if a rev limiter is triggered by the rev limit output.
The output seems to latch in this low state if the engine doesn't start.

Is there a solution? Will the behaviour of this output be changed in the new firware?

[dermot]

I don't know if Brent has this in any plan to fix, but anyway you can avoid it with eg a timed relay, you can buy such from electronics suppliers as a "black box". Then just enable the line via the relay for first (say) 30s from ignition on...hopefully one won't rev it to bits in the first 30s.. :v)

Messy but should work...

Dermot.

[David Withers]

It's not a very neat solution but as you say, it should work.

I have recently upgraded to the latest "interpolating" beta software. The output is better behaved but still triggers for roughly 150 msec soon after the engine starts cranking. The rev limiter does work with this short duration event but it is not ideal. With luck Brent will be able to fix it for the final release.