apex tach wire

[Turbor]

anybody can tell me the tach wire color? from what ive seen, its looks to be the blue/yellow, but if im right and god knows i hope im wrong, that wire comes straight from the ecu and drives other stuff also. Now, my problem is we installed a stand alone management system on my sled and neede to modify the flywheel to get it to work, so i now have half less teeth on it than before , so my tach reads half of what its supposed and my headlights dont go on at it idle, only when i rev up the engine... i know whats the wire that comes out of the crack sensor, and thats the onle id like to double the pulses, but its only a 1.16volt signal, and i cant find a pulse doubler for that kinda low voltage. so im thinking of doubling the pulse right before the tachometer and plug the sleds lights on an ignition power. But i need to find the tach signal wire gefore the tach tho, thanks!

 

[FLYBYU]

Tach of the injectors. Thats how we do it with sledstarts

 

[Turbor]

exactly what i tought and not what i was hoping forr....

 

[FLYBYU]

Easy to do. Are you using stock injectors or running larger. Fuel controller? Fuel controllers changes pulses input to injectors which will make tach read funny even more when you have larger injectors and you have to take fuel out at idle it changes the frequency pulses. If you do that might not be best place either. Coils? They pulse

 

[Turbor]

nah all of that wont work, the apex tach signal going to the tach is sent by the ecu and in that wire, theres other signals also, so you need to change the pulse before the ecu, the cranck sensor is the one that i modified and is the one sending the tach input to the ecu, so because i cant get to the tach directly, i have to modify the signal of that wire. But its a very low voltage signal 1.16v so you cant give it a pulse from an injector or coil, if i could have gotten to the back of the tach, that would have worked... lost alot of time ont this, and have no clue what to try next.

 

[FLYBYU]

These race guys on here run racepaks, they should know how to tap into tach signals

 

[FLYBYU]

msd ignition? They make a tach adapter

 

[Turbor]

all of this wont work with the stock tach... using an aftermarket tach would be a no brainer, but i want the stock tach to work!

 

[FLYBYU]

Haven't seen that yet at any races