Megajolt, was running, now dead?

[DaleB]

Hi All,

I installed megajolt a few months back and have been running a good few hundred kilometers with it already. Over the holidays I was in the mountains doing some rather wet mountain exploring in the Eastern Cape (South Africa). The 3.9i Range Rover went well all day, parked that night but would not start the next morning. No spark. Fortunately I still had the dizzy and coils so I went back to that for the rest of the trip.

Getting home after my 4000km trip ) of which only 1000kms were with the megajolt, I have started looking for the fault. If I run the system in tandem I still have no spark although I can see the revs in the megajolt software so the VR sensor seems to be working. That was my first thought. I have power on the coils and on the EDIS 8 module, obviously also on the megajolt unit. Still no spark. All wiring seems sound.

How realistic is it that the EDIS 8 module is buggered? They are scarce here in ZA so not so easy to swap out just for the hell of it?

Any ideas?

[nicksmelly]

The EDIS module on it's own should make the engine run, in limpy mode without the Megajolt connected as long as the VR sensor is sending the correct signal to the EDIS.

I'd be checking the wiring between the EDIS and the coilpacks. Not too difficult with a multimeter to check continuity.

[FridgeFreezer]

What Nick said, if you unplug the EDIS from the MJ the EDIS on its own should run the engine at fixed timing. If it doesn't, then you need to check the wiring for the EDIS.

The fact that you are seeing RPM's means the VR is OK and the EDIS is seeing the VR signal and passing the PIP signal to the MJ, so the EDIS and MJ are probably working OK. I'd check the coil wiring. It's possible that the coil-driver side of the EDIS is burnt out, but very unlikely as they are incredibly reliable and self-protecting.

[DaleB]

Thanks. How does one go about monitoring the firing of the coils with basic equipment(no scope)? I have power on the coils. How do I see if the EDIS is telling the coils to fire?

With a test lamp to a known earth I get 'light' off all three pins.

Will run through everything again tomorrow. Good to known that the EDIS is normally not the cause.

[DaleB]

Rechecked the wiring. I have a 0,05v drop from battery voltage on the positive to the coils, so that is ok. I have a 0,3 ohm resistance in the coil triggers between EDIS and the coils. So that is ok.

I wired the coils directly to battery earth, thinking maybe a bad earth.

Nothing, na-da, zip... no spark from Megajolt system, starts and runs well on Dizzy. I can still see the rpm's in the software.

I guess I have to import a replacement EDIS 8?

[elbekko]

So with a spare/old spark plug in one of the leads, you don't see any spark?

Do you have a multimeter that can record maximums? If so, set it to that function, and put it on the sender wire between MJ and EDIS, and see if anything registers.

If that gives the expected result, then it's time to start sourcing a new EDIS module I'm afraid.

[Bowie69]

With 12V to the centre of the coil pack, and a lead and plug resting on the engine, short one of the outer pins to 12V and then release, you should get a spark.

It is possible that you have had both coil packs die, I suppose, hence the above test.

Then as above, probably time for a new EDIS8, good job you still have the dizzy!

If it is indeed the EDIS, I would triple check the wiring to it, there maybe something daft in it which has caused the failure, they are very robust units TBH...