Tacho, Revs, PIP and SAW

EDIS and Megajolt installation related topics. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_vehicle_installation_guide">Vehicle installation guide</a>

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

Tacho, Revs, PIP and SAW

Post by Tadhg »

Hello all. I've a Mini in which I'm trying to install an MJLJ v4. I've wired everything up, but haven't yet switched from the dissy and coil to the coilpack. I'm still, effectively, testing. It's only been about a month. :oops:

I've managed to get the MJLJ communicating with my laptop. I can read MAP and Auxiliary Inputs. :) However, I've had no success getting the software tacho to work, or the tacho in the dash. :?

I did my wiring over a period of time, so I've only just realized that I could have the PIP and SAW connections back to front (I soldered it up, put heat shrink over it, and am unable to test the wiring). So, I'm trying to determine whether or not I've got my connections the right way round. My wiring colours don't align with anything on here, so I'll label my wires 'red' and 'white'.

If I look at the Troubleshooting Guide, it states:
5.You can also check the PIP signal using the AC setting of a multimeter. with the engine running you should see an AC reading that goes away when the engine is not running.
I've checked the other items, except for using an oscilloscope (I don't have one) and confirming the wiring (which is what I'm currently attempting to do).

I've also found plenty of sites online - including here and here - suggesting that the PIP line should give a +12V signal. :?

My first testing was using a LED. It worked when earthed from the Red wire, but not the White wire. The Red wire gives a +12V reading with my multimeter. But it doesn't give an A/C signal. :? In fact, the White wire gives the A/C signal. :shock: My original setup was to have White as PIP, but after many checks of connections, it didn't give me anything to indicate I had it correct. :(

So... I'm wondering if anyone can advise on the multimeter and LED tests, and which way they'd hook it up.

I'm also wondering, does the Tacho Out (from the MJLJ) require the Coilpack hooked up to function? Or should it work regardless of whether or not there's any signal going from the EDIS to a coilpack?
Mini A series rpm tacho software edis pip saw - search terms

brentp
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Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

having the PIP and SAW wired backwards is a common error and would certainly result in a "No RPM" condition.

Did you figure out your problem?
Brent Picasso
CEO and Founder, Autosport Labs
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Tadhg
Posts: 9
Joined: Wed Aug 15, 2012 2:38 pm
Location: SE Queensland, Oz

Post by Tadhg »

Hi Brent, been on holidays since the day you posted, only back tonight. Hope to get at it in the next couple of days...

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

Post by Tadhg »

Ok, problem solved. Both PIP/SAW and the VR Wires were crossed. So, my description of PIP is that it gives off an output that will light an LED test light (+12V), whilst SAW won't light an LED test light. Regardless of polarity.

The VR wires are only giving off about +1.5V (DC) on the choke (about 1200rpm), but they're still working, and the tacho's working, too, off the MegaJolt, in spite of the coilpack not yet being connected. However, with the MegaJolt now reading everything, I think it's time to set the timing and hook everything up. :D

Now, to figure out why every time I plug the laptop in, it's forgotten the Auxiliary Input data (the scale's always corrupted, the advance correction's always zeroed, and the user output one's always changed)... :?

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

Post by Tadhg »

Update - vehicle's running. :) Running beautifully. 8)

I did manage to mix up six of the wires total in the installation - obviously PIP and SAW, plus the VR wires, and then I mixed up EDIS 10 and 12 at the coilpack. None of the wiring colours matched what I had. No drama, no damage done, all running well.

There was one bit that was a little surprising. In setting the timing, we (myself and a mate who's got an MJLJ v4 on his Hilux) found that you can't retard the timing beyond what the MJLJ thinks is 0º. So, if you've got 5º of advance, you can use the offset in Global Parameters to get back to 0º. But if you're at 0º, then you can't offset back to -1º. Not a big deal, just interesting to note. :)

Now to ask about Auxiliary Input tables... Time for a new thread. Or at least a different one.

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