random ignition cut

EDIS and Megajolt installation related topics. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_vehicle_installation_guide">Vehicle installation guide</a>

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chris_1300
Posts: 2
Joined: Mon Jan 07, 2013 12:20 am

random ignition cut

Post by chris_1300 »

Hi guys,

having an intermittant problem with my MJ system.

Was running V3 system and had no trouble at all, running with a maximum advance of 25deg. The system ran on this 'safe' map for two months with no problems at all. Before Christmas I tuned the map to give more advance at higher rpm, freeing up the engine at the top end. Since this, I have had an intermittant (probably 1/4 of the time) fault where the engine will simply die at approx 4.2k. Electronic tacho connected to mj output drops to zero. The only way to reset it appears to be to blip the throttle several times. I have since changed to a v4 unit with still the same issue, however if I drop the timing back again it doesn't happen. Running the engine on distributor but with the rev counter still readinfrom the megajolt, the tacho signal appears stable, no jumping around or cutting to zero at the higher end of the rev range. Any ideas?

Regards
Chris

brentp
Site Admin
Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

This sounds like the EDIS module losing sync with the trigger wheel.

You may want to check if it's loose or moved out of alignment.

You should also check if the bracket flexes at all; if it does, the engine may cause excessive harmonic vibration at a certain RPM (often in the midrange like you're observing) , which can cause the EDIS module to lose synchronization with the trigger wheel.

Hope this helps! Let us know what you find out.
Brent Picasso
CEO and Founder, Autosport Labs
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