Troubleshooting - No Spark

General Megajolt Questions and Answers

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Tadhg
Posts: 9
Joined: Wed Aug 15, 2012 2:38 pm
Location: SE Queensland, Oz

Troubleshooting - No Spark

Post by Tadhg »

Hello all. I've got an MJLJ (v4) running in my Mini. Or at least, it was, for about 18 months. This week, it's decided not to work anymore. It's running an EDIS (obviously!) and a standard Motorcraft Ford 4 cylinder coil pack. And a Ford VR sensor.

When it died, I thought it'd run out of fuel. That's the feeling it gave. I was about 15km into a 17km drive home, having been on the highway, so the car was warm.

I've tested the VR signal, I'm getting 0.9V - 1.0V AC at the EDIS. I haven't been able to test the PIP or SAW.

I've plugged in the laptop to the MJLJ, but I had issues connecting. Think it was mainly USB to Serial issues. Did connect at one point, it wouldn't read RPM while cranking (but Brent's posted that it doesn't read RPM below 450rpm), but could read the rest. The MJLJ also has the green LED on.

Lastly, I've tested the coil. I've got 13.6k ohms across the poles, and 0.4 ohms across the pins.

I'm not sure what else I can test? There's plenty of great info on how to test when you're setting up a system, but there's not a simple, consistent 'this is how you troubleshoot no spark' guide.

Any help you could give me would be appreciated.

brentp
Site Admin
Posts: 5986
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi,

These steps are likely the best for verifying all the voltages you need to see across the system.
http://www.autosportlabs.net/MJLJ_V4_ve ... tion_Steps

Let us know how it works out and what you figured out!
Brent Picasso
CEO and Founder, Autosport Labs
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