No spark with megajolt.
Turbo Mini Forums

Hi all,

I have a bit of a problem with getting a spark with megajolt. I have tested the wires and all are good. i have power at the coilpack and edis module. I have been trying to get a spark without megajolt connected. I only have a tester light to test for a current and im not sure what the voltage is to the vr sensor. I getting no current (i presume) from the vr sensor even when i turn the engine over. Ive tried swapping the vr sensor wires over but no joy. Im starting to think the sensor is dead. i bought it off ebay withh the coil and edis module. Supposedly tested and working. Is there any way to test the sensor? I have the sensor set up so it is really close to the trigger wheel (0.25mm). Could this be too close?

Any help will be greatly appreciated.

CHEERS!!

Is the sensor polarity correct? It only works one way round. worth swapping the wires over to check.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Ive tried it and i still get nothing. new sensor i think next.

Probably , as if you reverse the polarity on the sensor it has had it !

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

As per Wil, they are not powered devices (unlike an electronic dizzy which you will fry if you connect the polarity wrong).

They are passive devices and if wired the wrong way around the ECU/EDIS can't understand the missing tooth signal as the "zero crossing point" is the wrong way around.

A couple of simple tests,

1 - does a steel washer stick to the end of it ??? They have an internal magnet to generate the very low output voltages from the teeth passing the coil and a good one will grab a washer easily.

2 - if you can borrow a DVM or multimeter, measure the resistance between the two pins, it should be about 3-400 ohms from memory. If the coil inside the VR sensor is open circuit (infinite resistance) the sensor is dead.

EDIT - only do the resistance test with a proper DVM/multimeter. Don't try a simple "lamp test" as (a) the coil resistance inside the sensor is too high to pass enough current to light a normal bulb anyway and, (b) the current a normal bulb and 12V would try to pull could burn the VR sensor's coil out.

Edited by Rod S on 18th Mar, 2010.

Schrödinger's cat - so which one am I ???

Another fact learned by making a prat of myself !

If you do get a multimeter measure the ohms at the coil pack. measure between pins 1 and 2 then 2 and 3.should be about 0.4 and 0.6 ohms.if you cant do that its best to change them for new items.

silly question, however it is something that got me twice. is your trigger wheel set at 90tdc as mine kept on slipping, check it with a timing light.

Is your power supply for the EDIS and coil wired separately from your MegaJolt box?

Mine isn't so if I disconnect the MJ the EDIS dies as well.

at the moment i don't have the megajolt plugged in. i have power the the edis module though and the coilpack (both off the top pins on the fusebox on the bulkhead) . i changed the sensor and still no joy. even if the timing was out i would still get a spark wouldn't i? I have'nt got a proper multimeter so i will struggle with that! i'm sure i can borrow one from somewhere. Cheers. i'm totally lost now.

Yes you will get a spark regardless of the timing wheel position. Have you tested the coil pack?

Another good test to see if the EDIS is working is to hook it up to the megajolt. With you laptop connected and monitoring the RPM you should see around 300rpm while cranking. If not then the EDIS is not communicating correctly and possibly not working.

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can you use the phone line type connection to your laptop or do you have to have a converter to usb? i have tried plugging it in but i get ''could not open port''. Cheers

ah another megajolt cunundrum!
i wired my edis in backwards,
its an easy mistake.....

cheers for all the advice. got it solved now. My edis module doesn't have a connection for a rev counter so i had coil 2 wired into the ground and the ground was wired into the live. Switched it all round and it works a treat. Thanks again!