With the stock ECU my Mexican bug used to start immediately like this:https://www.youtube.com/watch?v=d2GNVS3a5x4
However, since moving to Megasquirt it take a few seconds to start. I have dialed in the start up sequence and I have been playing around with the settings for nearly 2 years now and still it doesn;t get close to starting as well as it did with the factory ECU.
It seems like the spark takes a few seconds to kick in (I'm using wasted spark) and although I have reduced the "skip pulses" from 3 to 2 it still make no difference.
IS there anyone out there using MS on a bug that has managed to get it to start quickly?
How do I get my bug to start like factory
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- Joined: Sat Dec 13, 2014 1:01 pm
- ps2375
- Posts: 397
- Joined: Mon Aug 18, 2014 8:04 am
Re: How do I get my bug to start like factory
Found this explanation on a forum w/ a google search: "It's a number of tach pulses to skip on startup before sending spark. Useful to build oil pressure before spinning the crank quickly or to get a good sync. 3 is a decent number to use."
You could reduce it more if you want. Have you tried '0"?
You could reduce it more if you want. Have you tried '0"?
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- Posts: 41
- Joined: Sat Dec 13, 2014 1:01 pm
Re: How do I get my bug to start like factory
It needs a couple of tach pulses to get its timing. I haven't tried reducing to zero because the difference between 3 or 0 revolutions of the engine when it's cranking at 200 rpm is about 0.9 of second and I am trying to figure out why the engine cranks for 2-3 seconds. I have reduced it to 2 and that's made no difference so I don't think that's where the issue lies.
It would be helpful if anyone has a video of their MS bug starting to use as a comparison.
It would be helpful if anyone has a video of their MS bug starting to use as a comparison.
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- Posts: 41
- Joined: Sat Dec 13, 2014 1:01 pm
Re: How do I get my bug to start like factory
It needs a couple of tach pulses to get its timing. I haven't tried reducing to zero because the difference between 3 or 0 revolutions of the engine when it's cranking at 200 rpm is about 0.9 of second and I am trying to figure out why the engine cranks for 2-3 seconds. I have reduced it to 2 and that's made no difference so I don't think that's where the issue lies.
It would be helpful if anyone has a video of their MS bug starting to use as a comparison.
It would be helpful if anyone has a video of their MS bug starting to use as a comparison.
- ps2375
- Posts: 397
- Joined: Mon Aug 18, 2014 8:04 am
Re: How do I get my bug to start like factory
how are you priming pulses setup? and your cranking pulses? And do you have an AUX Air valve/idle valve?