CDI problem, no spark.

[vr423q]

Hey guys,

I have recently purchased a Vr4'd lancer gsr that has a M&W Pro 12 CDI installed and am currently having problems getting it started. There was an initial problem with the cdi unit and that has now been fixed after sending it back to be repaired.

I have followed the wiring diagram from M&W, as seen here http://www.mwignitions.com/pdf/Pro12_S3.pdf however still cant get any spark. The car is running an EMS dualsport and the stock vr4 coils.

The unit has a number of inputs and outputs including 2 12V's, 2 grounds, 2 triggers, 1 ignition and 2 Positives and 2 negatives for both Coil A and B plus a few others. I have wired the 12V and grounds directly to the battery, the 2 trigger wires from ignition 1 and 2 off the EMS, ignition wire from a 12v switched ignition source, and finally the 2 positives and 2 negatives individually wired directly to the respective terminals on the coil pack. Also for the trigger edge selection I have left falling edge selected on both cdi and ems.

I have also followed the test procedure off the website which has led me to either faulty wiring or ecu not triggering the cdi unit. I was initially confused with the stock wiring on the coil pack, as it had separate wires from both negative terminals to the 3 pin plug but had only one from both positive terminals including a jumper between the 2 and also a third wire to a small capacitor on the side of the coil pack.

Am I missing something after removing the stock wiring and wiring the positive and negative for the coils from the cdi directly to each coils respective terminals?

Another thing that is confusing is that there is a pulse being sent from the ecu to the cdi unit, however no signal coming out of the positives and negatives for the coils from the cdi.

Hopefully someone that has wired one in can help out. Any help is greatly appreciated.

Cheers

 

[EVO-00X]

Do you still have the OEM ignition module plug with wires hanging off it where you cut it off.
If so cross reference the following pinouts from the oem ignition module to the colour of the wires you have wired into the M&W plug.
The M&W diagrams look pretty straightforward. If its wired up right, then it be a dwell/ timing settings in the ECU.

 

[vr423q]

There wasnt an ignition module in the wiring, as was told from EMS that it isnt required, as the cdi acts as it. Have since played around with the wiring and cross referenced the pinouts from that handy diagram of yours plus the circuit diagrams from the workshop manuals to the wires off the cdi unit and still cant get any spark.

Need the car going to get rego so have wired in a J122 ignitor for the mean time till i can get my hands on a J722T or get the cdi to work. Car starts first crack with the ignition module wired in.

 

[EVO-00X]

Any reason why you want to run the CDI? huge boost?

 

[vr423q]

It was on the car, so thought I'd try and use it. Will worry about getting rego and the car all sorted out first, running wise and then throw it back in and have a play. Thanks for the help though mate.
Was trying to avoid going for a tune straight up, as would like to throw a few more mods on before going for one.
Would running the ignition module instead of the CDI have an effect on the tune? I'm thinking it might considering the greater energy and spark the CDI provides.

 

[EVO-00X]

I would have thought that CDI would really be a benefit at higher rpm to provide a quicker, cleaner and more efficient spark.
I know its better all round than your normal ignition system, but our oem systems seem to be pretty good even at 1.5 bar boost.

 

[khubner1]

i wouldn't expect it to have an effect on the tune as long as you set the timing the same from std to cdi

 

[bazeng]

It may improve efficiency with a better burn.

It might also allow more boost without spark blow out.
It doesn't mean you can run massive gaps or anything like that, treat it as a standard system when tuning. My CDI system still gets misses and needs a gap of about.6 to.8mm

 

[caged]

Im not a big fan of CDI unless running fat with meth, they put out an intense but very short spark duration and yes it can change the tune slightly. Just run a set of 80$ ls1 or ls2 coils if you want good spark, I run about .9mm plug gap with 37psi of boost now with no missfires. What plug leads are you using because the CDI's dont like carbon cored resistor leads and not all spark plugs, I wouldn't even bother running it on shitty std coils and would defiantly wire it up using shielded twisted paired wire.