probs getting tacho working with motec m4 and m&w ignition

[86psi]

hey fellas ran into a major headache and am after some tecnical advice. ok i have installed a m&w coil over plug cdi set up on my evo 3 running a motec m4 the way i have it running is a dual trigger setup running coil 1&4 on ignition output 1 and coil 2&3 on ignition output 2 the car runs great.

the problem is if i connect the tacho to either of the ignition outputs my tacho only reads half the rpm and for some unknown reason it wont even get a reading from the tacho output on the cdi.

so my question is can i get the signal from ignition output 1 and maybe use a signal manipulator to double the signal this is what im talking about

My link

or can anyone think of a way i can get both trigger signals to the tacho without interfering one another

thanks in advance

Tim

 

[bazeng]

You should only really be connecting your dash tacho input signal wire to either the m4 tacho output or your ignitor tacho output. Are you running cdi? If so, your cdi should also have a tacho output.

You are only seeing 1/2 the rpm simply because the tacho is only receiving 1/2 of the ignition pulses.

 

[86psi]

yeh but for some reason its not reading the signal from the tacho output on the cdi and im out of outputs on the motec to make a tacho output

 

[bazeng]

Which cdi is it? pro14?

 

[bazeng]

The other option is to get a motec expander unit to run seq ign and also free up that output for ign 2 to use for tacho instead.

 

[86psi]

yeh mate its a pro14 hmmm never thought about the expander unit thats actually a good idea

 

[bazeng]

They are quite cheap also. Only about 300 or so.

 

[86psi]

awesome is there anywhere online i can get one from

 

[bazeng]

Hmmm. Where are you based? I get my motec stuff from Springy Motors. At least if anything goes wrong, warranty is easy.

 

[86psi]

im based in townsville i think dynolink is the motec distributor up here so will get onto them. thanks for your help champ

 

[bazeng]

$333.00 for the unit from Springy Motors.

 

[bazeng]

Thats the rrp in the motec book.

Good luck bud. Also remember to use falling edge on the motec and cdi.

 

[86psi]

awesome thanks heaps mate yeh already on falling edge. i cant believe how much better the engine runs now over the stock ignition deffinatly well worth the dollars pitty i never thought to do a back to back to see if there is any performance gains

 

[runuts]

Another option is to run the factory ignitor. It will give you a tacho output. You'll just need to change the firing edge of the CDI. No drama really.

 

[86psi]

back on this subject i have just wired in the iex expander and it wont start. my guess is cause the motec is firing ignition outputs 1 and 2. do i have to change this in the motec for it to fire all signals from ign1