i am getting properly annoyed with my MJ unit.
I cant get the rpm to read on the configurator and have run out of ideas. I have:

checked shielded cable and that it is earthed
cleaned all connectors
checked all connectors
checked connectors are in right place on mj and edis
pulled out my hair

Any ideas?

As it is displaying no rpm on the configerator then my understanding is that the engine is running in limp mode home

Is the engine running, and you are only missing seeing an RPM figure in the configuration software?

ETA : If the engine is running, the EDIS is working just fine along with the crank sensor and wiring. The problem is somewhere between your EDIS and MJ. If the EDIS is not getting a signal from the MJ then it will just run at 10 degrees BTDC.

[Edited on 14/7/12 by scudderfish]

Can you simplify the wiring down to this?



If the MJ is talking to your PC then the power to the MJ is correct. Is the MJ earthed to the same point as the EDIS?

does the cursor move around the map with load and rpm change and does the indicated advance value change. could also double check with a timing light.
i think when its in limp type mode the advance shows 0 but the eds has given 10 deg. may be wrong though.

If you change the map and commit the change does the idle change?

Does the software find the mj on the com port?

If its tps can this be calibrated?

What version of mj is it?

Just a few bits of info which will help us to help you.

Cheers

R

it runs and so yes seems to be the connection between the MJ and the edis. I have just made it so they use the same earthing point. I have also following the autosports guide which says no rpm is due to a pip error. It says to measure voltage across it to earth which should be 12v. I have 11.5v but didnt think that would hurt?
ive just been messing with it and when i blip the throttle it almost stalls and almost sounds like its firing on only 3 cylinders but not quite so bad. arrrrrrrrrrrr

when i push the pedal it moves on the tps so i know its communicating.
I used the mj supplied shielded cables and twisted the wiring wrapping into a point and put a connector on it to put to earth. Could i of not used thick enough cables to earth it?

When you measure 11.5v is that at the EDIS end or the MJ end? If you unplug both the EDIS and MJ, do you definitely have electrical continuity along the PIP line between the plugs?

Regards,
Dave

i ired in the tacho out on the megajolt but that didnt work so used the connector on the edis instead. For the mj unit to power up that tacho cable has to be earthed. Could it be a problem caused by that? i will try removing it tommorrow.

The tacho is unlikely to be the problem, but unplug it until you have proved that nothing else is wrong. Right now, the engine runs so from that we can deduce that the EDIS works, the coil pack works, the crank sensor is working. If you have a timing light you could probably confirm the 10 BTDC timing as well. You aren't seeing an RPM in the config software, so the problem lies between the PC and the EDIS as the EDIS is seeing the engine turning. The MJ is powered and the serial connection is OK as the PC is talking to it (assumption) The problem then is either the wiring between the MJ and the EDIS, or there is an internal fault in the MJ. The PIP signal tells the MJ the revs, and the SAW tells the EDIS how to swing the timing. I would disconnect everything from the MJ apart from the connections shown in the diagram I previously posted. With that wiring, the engine should run, and you should see RPM in the config software. If you don't, you have a lot less to check, double check, and triple check. If you ever find yourself saying 'I know that is right', don't believe yourself and check it again. Once that works, test it all again each time you reconnect something. If it stops working, take what you just connected back off again and examine it.
There is a fault somewhere, and it can be found. Just approach it from the position of trust nothing until it has definitively proved itself to be correct, and only change one thing at a time between tests.

Regards,
Dave

thanks dave, thats what i will do today then and let you know how it goes

good news. I cut the wires from the megajolt connector off and temp fixed the basic one and hey presto it works.
Just waiting for a new connector from trigger wheels.

Thanks for the help....big relief