Help Please no spark in Megajolt

javierant3 · Post by **javierant3** » Mon Dec 27, 2010 12:40 pm

Hello I have installed recently megajolt in my car. It`s very straightforward in my case because I have a Ford engine with marks in the flywheel, so the installation of sensor is very easy.
If it makes any difference I have installed my unit with the internal rev limiter board and it`s a megajolt E.

However when I come to start the engine I have no spark, and the engine obviously won`t start.
I have made some comprobations, and I don`t know where the fail is...
I have conected the edis module alongside with my original distributor and started the engine with the original ignition and the megajolt functions correctly. It shows the rpm of the engine correctly, and controls my shift lights.
I have ohm the coil and think is good. About 1.0 ohm primary and 13 Kohm secondary.

Also I have checked the coil outputs and my multimeter shows about 12 volt with engine stopped, and about 13.7 with engine running, which I presume is the same voltage as the rest of the electrical installation of the car.
The coil output would not show lower or fluctuate as the EDIS fires the coil?
I have tested two differente EDIS and both do the same.

At this point I am lost, and don`t know what to do, maybe the two EDIS are fault? However it communicates with megajolt correctly.

Please if anybody have any suggestion, I will be glad to hear.

Thank you very much in advance

Post by **brentp** » Wed Dec 29, 2010 8:20 pm

Hello,

On the ford coil pack, the center terminal is the one with the 12v feed. with the car to 'on' but not running, are you reading 12v here?

Also verify proper power and ground for the EDIS module.

Finally, your problem describes ' no spark' yet your engine is running? A bit confused by this- do you have the engine running on a different engine management system while working to adapt the Megajolt / EDIS system?

javierant3 · Post by **javierant3** » Wed Dec 29, 2010 8:54 pm

Yes, I am running my engine with the original ignition while I am adapting the megajolt system.

If I measure between central pin and the sides with the ignition in on , but with the engine stopped I have battery voltage in the two sides. The +12v switched for the edis is taken from the original feed for the coil in my car, and the +12v for the DIS coil goes from the megajolt, because I have installed the rev limiter module. The ground is exactly the same point for megajolt and edis.

Next thing I want to do is to drive the coil directly from +12v switched and disconnect the megajolt and see if there is spark, but at the moment I haven`t had the time to verify. Rechecked all the wiring and all is connected in the right place.

javierant3 · Post by **javierant3** » Thu Dec 30, 2010 9:34 pm

Hello again, today I got the system to work! I have connected directly the coil to +12v switched directly, via the same line that the EDIS is connected to (+12v coil original connection of the car) bypassing the rev limiter module.
First place I have checked spark without megajolt connected. The engine started, but with the 10 degree fixed it ran not very well. Second I have connected the megajolt and all were perfect and the engine response is great!

Need to open the megajolt and check the rev limiter module. One strange thing is that with the ignition in off position if I ohm the coil output of the megajolt and a direct ground I can measure about 44 ohms. If I put the ignition in on the circuit goes to infinite ohms, open circuit.
Is there any method for checking the rev limiter module?

Thanks again for all.

Post by **brentp** » Thu Dec 30, 2010 10:43 pm

Glad you made progress, but your additional comments are not entirely clear.

With the hard rev limiter module installed you need to power the coil via the terminal "Coil Power" on the Megajolt connector.

See:
http://autosportlabs.net/MJLJ_V4_vehicl ... Jr._Wiring

Make sure the power to the Megajolt provides enough current (10A ) to also supply power to the coil.

With the coil pack connected in this manner, you should measure +12V on the coil supply with the ignition to 'on'.

javierant3 · Post by **javierant3** » Thu Dec 30, 2010 11:32 pm

Thank you for your support. Sorry for my English I`m Spanish, but I`ll try to be clearer in my writing.

I already have connected the coil positive terminal via the Coil power terminal of the megajolt. Strange thing is with ignition in on position I have +12v on the coil supply but there is no spark.
The power for the megajolt and coil is taken from +12v switched with a 15 amp fuse.

The only thing I am suspecting is I have taken the +12v switched for the edis from the original connection to the car`s coil, but this is a switched +12v.
The megajolt and coil +12v switched are taken from the ignition switch directly. Maybe different locations for the supply can lead to this fail?. I don`t know, but the two supplies are from the same electrical circuit.

Is there any method for checking with a multimeter the rev-limit board?

thanks again and merry christmas!!

Post by **brentp** » Fri Dec 31, 2010 6:00 am

This is a simple test, but make sure you have 12V at the coil **when the engine is cranking**. Sometimes the power might be interrupted when the ignition key goes from 'ON' to 'start'.

javierant3 · Post by **javierant3** » Fri Dec 31, 2010 1:23 pm

I have tested and I have +12v when cranking.I Think that the rev limiter is at fault because when I put the ignition to on there is no current from the coil output of the megajolt. I have tested it with a halogen bulb and it doesn`t illuminate at all.

javierant3 · Post by **javierant3** » Fri Dec 31, 2010 2:53 pm

Strange thing , I have opened the megajolt unit to examine the rev limiter and check it. Curious thing is if I feed the rev limiter board directly it seems to work ok. Between +12v and coil output the multimeter goes to almost zero ohm. If I cut the power to the board there is about 18 ohm between +12v and coil output.

Strange thing is with the megajolt connected to the car when I turn on the megajolt ,+12v and coil output terminal goes to 44 ohm.

Post by **brentp** » Fri Dec 31, 2010 3:45 pm

Thank you for the update. What do you mean by "feed the rev limiter board directly"? Which connection on the rev limiter board are you applying 12v to?

A picture or diagram of what you are working on would be helpful.

javierant3 · Post by **javierant3** » Fri Dec 31, 2010 4:31 pm

Forget the last post, I was wrong. I have finally checked the output of the rev limiter. It can turn on a led, but for example not a H7 55 watt bulb.

Definitely, I think the rev limiter board is defective. Maybe the mosfet, and always the current is pasing through the resistors?

Post by **brentp** » Sat Jan 01, 2011 2:06 am

Thank you for the update.

When you are performing this test, do you have a proper and consistent ground connection to the Megajolt unit at the same time?

Also- did you ever only have +12V connected to the megajolt *without* ground connected while doing this test?

javierant3 · Post by **javierant3** » Sat Jan 01, 2011 4:32 pm

Thanks for the response Brent. When I was checking the rev-limiter the megajolt and EDIS had the same ground connection to the chasis with a bolt. With the megajolt connected and the green led illuminated I checked between COIL and +12v connections at the rev-limiter board and my multimeter showed about 9 ohms. With the megajolt disconnected it showed 18 ohm.

At this moment I have disconnected the rev limiter and connected the +12v connection to the COIL connection inside the megajolt, making a bypass, and the car runs perfect. Much more stable idle than before.

Post by **brentp** » Wed Jan 05, 2011 5:53 pm

After further testing if you're convinced the rev limiter board is defective, please email us at [email protected] - we would like to receive it for further testing.

Thank you for your patience debugging this issue!

javierant3 · Post by **javierant3** » Wed Jan 05, 2011 6:36 pm

Thank you for the offer Brent. I purchased the megajolt kit and rev-limiter from trigger wheels. I emailed them and agreed with them to sent the board for testing.

Now I am using the car every day and made about 100 km and what a difference! Much more stable idle and my engine is smoother than before. Also it revs up better.
In the next days I want to tweak the map a bit to get the max of my engine.

I`ll update with the results of the testing.

Thanks again!