No rpm shwing in configiratir...

Spitty · Post by **Spitty** » Sun Apr 14, 2013 12:12 pm

Hi,
Have installed MJLJ in basic mode ie Ford Edis and MJLJ with simple +ve, -ve, pip and saw connections.
Now, the edis must be working as the timing is rock steady at 10 btdc with the MJLJ disconnected.
However, when i plug the MJLJ in, i don't get anything showing on the rpm dial in tbe configurator setup; i get manifold pressure but nothing else?
The VR must be working for the edis to control the advance but why don't i get any rpm's showing and no ign control from the MJLJ?
I can 'get' the default map shown in the unit and write to it to, but why no control over the advance or rpm figures??
Co-incidentally, could this tie in with the fact that my cars rev counter also doesn't work when in MJ mde but dies in conventional?

Any help is much appreciated!

Alex B · Post by **Alex B** » Sun Apr 14, 2013 4:49 pm

First of all check if the MJ is getting the PIP-signal. Look at the Installation Guide for the correct pin and the voltage.

http://www.autosportlabs.net/MJLJ_V4_ve ... tion_guide

Disconnect the Molex plug. Use a multi meter to check the signal. With engine not running it should be ca.12 volts, during cranking or running ca 5.5 volts.

Alex

Spitty · Post by **Spitty** » Sun Apr 14, 2013 6:37 pm

Thanks Alex, will check and let you know; i'm always meticulous about connections but have been known to get them wrong. Trouble is, it's sometimes hard to see ones own mistakes!

Spitty · Post by **Spitty** » Tue Apr 16, 2013 7:00 pm

Right, i've checked the supply to the MJ and thats wired correctly.
I've checked the PIP & SAW connections and they're wired to the correct pins on the Molex plug.
I've checked the voltage for PIP at pin 6 of the Molex and thats 12V.
STILL no rpm showing in the configutator and STILL no ign advance control ie STILL sat at 10 degrees BTDC.

I'm kinda getting stressed now at what should be a simple install; HELP anyone PLEASE!

Spitty · Post by **Spitty** » Sat Apr 20, 2013 6:19 pm

Checked all wiring and its as it should be.
Still no rpm showing and no control over ign advance.
Voltage at pip static is 14v and 7v when running.
Any deas other than chuck it in the bin and buy a competitive unit?

Post by **brentp** » Sat Apr 20, 2013 6:59 pm

Hi Spitty,

Sorry you're having problems with your install. So you're saying you can communicate with the Megajolt using the software (read / write ignition map, verified across power cycles), but it's not showing RPM while the engine is running?

The Megajolt gets the RPM signal by measuring the PIP signal, and controls ignition advance by replying with the SAW signal.

Is there another Megajolt user nearby (there must be 100's within a 10 mile radius

) with a known good install that can test your unit on their engine and vice versa? It could help also by tracing and comparing installation wiring as well.

let us know what you find out!

Alex B · Post by **Alex B** » Tue Apr 23, 2013 8:55 pm

Spitty, take the circuit board out of the casing and scan both sides in high enough resolution. It is easier to look for faults when you have the board larger than life on your screen. Publish the pictures also here, it might help. I had MAP-sensor issues which were due to a pin of one of the ICs that had folded up during installation of the IC. I hadn't noticed myself but Brent picked it out straight away.

Reheat all the soldering connections, it is always possible that a joint is not as solid as you think.

Alex

Post by **brentp** » Tue Apr 23, 2013 9:11 pm

Alex, it may be a unit that is pre-built and pre-tested - not made from a kit.

Spitty, let us know what you find out. As before, it would be good to find someone to test the Megajolt on their car and vice-versa.