Help! No rpm signal in the configurator.

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>

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Kieranzxt
Posts: 5
Joined: Mon Mar 25, 2013 12:52 pm

Help! No rpm signal in the configurator.

Post by Kieranzxt »

Hello,

I recently purchased a megajolt and initially the unit worked great.

However, my car will now only run on the edis fixed timing (confirmed with strobe) and it seems that although I am sending the PIP signal to the megajolt, it's doing nothing with it.

I have tried:-

Another edis unit
Running a standalone pip cable direct from the edis to the megajolt

The car starts fine but is obviously compromised with the fixed timing. The unit did work great initially. When connected to my laptop, I see the tips working and changing, I am able to upload and download to the megajolt, I just see no rpm signal when running.

Any ideas??

Kieran

Sent from my iPhone[/quote]

DannyP
Posts: 417
Joined: Sun Apr 09, 2006 3:48 pm

Post by DannyP »

Maybe the SAW line isn't getting back to the EDIS unit in order to change the advance?

Have you run the engine with a laptop connected and are you able to see the rpm change onscreen when engine is revved?

knifemind
Posts: 2
Joined: Thu Nov 28, 2013 11:23 pm

Post by knifemind »

I am having this same problem. I am getting vac signal, but no rpm is displayed on my laptop. I don't want to tear apart my wiring without having an idea where to start. Is the SAW line the first thing I ought to check? I have tried 2 different laptops and 2 dirrerent serial adapters with the same result.

brentp
Site Admin
Posts: 6275
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

If you are not seeing RPM but you are seeing manifold pressure change that means the PIP signal is not getting to the megajolt. Check your connections for both the PIP and the SAW connections. In the installation guide there is a section near the bottom for checking voltage levels.

Please post back with your findings!
Brent Picasso
CEO and Founder, Autosport Labs
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knifemind
Posts: 2
Joined: Thu Nov 28, 2013 11:23 pm

Post by knifemind »

You were spot on. I used a 4 wire shielded cable (because its what I had on hand) and somehow mixed up one of the wires, so my PIP was not even connected. It only took a few minutes to find the mistake once I knew where to look, and I've been on the road for about a week and a half.

BTW it's in a '85 Honda Prelude with an '88 Accord engine & Weber 32/36 conversion.

I love my Megajolt. Thank you.

brentp
Site Admin
Posts: 6275
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Excellent! thank you for your update, and thanks for your kind words!
Brent Picasso
CEO and Founder, Autosport Labs
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