doesn't read rpms while cranking

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

Moderators: JeffC, rdoherty, stieg, brentp

Post Reply
surferpete
Posts: 6
Joined: Wed Jul 27, 2011 6:47 pm

doesn't read rpms while cranking

Post by surferpete »

Hello. I am trying to start my new engine with the megajolt unit and it wont start. All it does is make some popping noises. Also the rpms don't go up on the laptop screen when the engine is cranked.

spandit
Posts: 129
Joined: Wed Dec 22, 2010 10:43 pm
Location: East Sussex, UK

Post by spandit »

I had this problem as I am running the ignition system off a voltage dropper (truck is 24V). When the battery isn't fully charged, you lose too much whilst cranking so the MJLJ isn't powered. Try using a small fire alarm 12V battery to power it whilst cranking. Once the engine is running, it should be fine

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Actually, the Megajolt does not measure engine speed below about 450 RPMs , and this is by design. In this phase th Megajolt is using th Cranking Advance settings.

However, the engine should still fire regardless. If you are concerned about low voltage you can monitor the LED on the Megajolt and/or measure the feed supplying the coil pack/ Megajolt / EDIS combination.
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

Sadam
Posts: 1
Joined: Tue Feb 03, 2015 6:46 pm

Post by Sadam »

Hi,

I just encountered simular problem. Checked my wiring over and over again to find out it was all OK. I did mis aligned the trigger wheel and that caused the engine to not be able to star. However I was focused on not having the RPM read put and was checking all of the suggestions from your troubleshooting section in manual. There was no info there about the software showing rpm only when it is above 450. I would have been a great help to know that earlier. I think it would be good if you could that in the manual as well.

Anyway managed to start the engine. Will be playing with the megajolt in a few days time but it's already a great device to have.

Adam

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Remember that the EDIS module alone can control ignition at the default 10 degrees BTDC. One of the first tests is to start the engine on EDIS alone to verify basic functionality, then add Megajolt to actually control ignition advance.
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

Post Reply