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rev limiter/ ecu fault
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Post rev limiter/ ecu fault 
im getting an intermittent fault on the rev limiter, unfortunatly when its happened i havent had a tester to hand to check but im pretty sure either the ecu is sending out signals when it shouldnt or the rev limiter is juts cutting in, it only happens on initial starting and is very random, ive changed the rev limiter for a spare board and it still happens so look like it could be the mjlj itself has this happened to anyone else

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The MJLJ measures RPM by timing the duration between PIP pulses emitted from the EDIS module. Consequently, sufficient noise on this PIP line can be interpreted as a legitimate signal, which would show up as an 'rpm spike' according to the firmware.

Aside from potentially falsely triggering the rev limiter, noise will trigger an extraneous SAW pulse to be sent to the EDIS module, confusing it and potentially causing unstable ignition advance.

Watch for reported RPM spikes by performing a datalogging session with the configuration software. After gathering some data, open the .csv file in a spreadsheet program and look for any high RPM spikes.

If you do see RPM spikes, go over the wiring for the PIP and SAW line, ensuring the cable shield is properly grounded and the connections are good. Also check the ground connection for the EDIS module and the MJLJ. Ideally, they would both be grounded at the same point on the chassis, to avoid 'ground loop' problems.

Check the above, and please report back your findings.

Last edited by brentp on Tue Sep 02, 2008 5:49 pm; edited 1 time in total

Brent Picasso
Founder, Autosport Labs
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thanks for the reply brent, its on a rolling road on saturday so ill check for spikes then

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