Megajolt Tps won't map

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

brentp
Site Admin
Posts: 6277
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi Dave,

I'm going to try to re-create what you're seeing. It's puzzling because the mechanism that makes this happen is pretty fundamental inside the controller firmware.

Question- are you doing this with a running engine, or just with the key to 'on'? As you move the throttle, does the Load gauge in the software move smoothly between 0 and 100%?

Finally, can you take a short video of this behavior and post it to youtube or similar?

Thanks,
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

brentp
Site Admin
Posts: 6277
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Dave,

I double-checked this. You must be testing on a non-running engine, correct? If so, then the bins will only update when the unit sees an RPM signal above a certain threshold. Between 0 and about 500 RPMs the system is in a "cranking mode". In this mode the bins are not calculated and therefore do not change on the display. So, once you have it running on an engine you should see the behaviour you expect. As before, you should be fine as long as you see the Load gauge move smoothly in the software.

If this is the case- please accept my apology for making you unnecessarily bang your head against the wall! This part had slipped my mind and I neglected to ask up front about running or non-running engine.
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

Dave R
Posts: 14
Joined: Wed Aug 22, 2007 7:15 pm
Location: AShbourne

Post by Dave R »

Brent,
Thanks for your last message; you are completely correct! I was in the garage when it arrived, trying to take a video of the megajolt in action. I showed that with just the ignition switched on but without the engine running, only load bins 1 & 2 lit up as the throttle was moved between 0 & 100%. When I started the engine, the correct bins lit up according to revs and throttle position just as they should.

I’ve been trying to upload the video to show what I found but my upload to You Tube has failed twice now. I’ll keep trying and add a link to this thread if I succeed because it might be helpful to others.

Quite why I had a problem still eludes me. I did observe the bins with the engine running but only saw load bins 1 & 2 illuminate as the revs moved up and down. I guess that one of two possibilities might have happened. It could have been working correctly all of the time and I might not have been pressing the throttle more than 10%. After all, it doesn’t take much throttle to rev up the engine with no load in the garage. Alternatively it could have been a poor connection in, say, the molex plug that ‘got better’ with all my fiddling and testing. I like to think that the latter is the more likely because it makes me seem less stupid.

All I have to do now is to get the tacho working. If the diode trick doesn’t work, you may hear from me again on a new thread!!!

Many thanks to Brent & Martin for help, advice and support. It’s very reassuring to know that I’m not alone when faced with problems that are too difficult to tackle with my limited knowledge.

Regards,

Dave

Dave R
Posts: 14
Joined: Wed Aug 22, 2007 7:15 pm
Location: AShbourne

Post by Dave R »

It must be my lucky day....I got You Tube to accept my video. Don't expect MGM to be quaking in their boots, but it might be useful to view. Here's the link. You could also search under 'Megajolt TPS problem'.

http://www.youtube.com/watch?v=6c8tRayYlgk

Regards,

Dave

MartinM
Posts: 433
Joined: Sat Aug 27, 2005 12:08 pm

Post by MartinM »

Nice video! Doesn't sound too bad for a Sprite either!

Any problems with the tacho...just post back here....

Post Reply