im trying to use an msd rpm switch to turn on vtec, problem im having is i cant get the rpm switch to put out its neg. trigger at the desired rpm, i have narrowed it down to the fact that the rpm switch is not getting a good tach signal, i have the tach signal coming from the neg. ignitor wire on the distro. but when i plug it in to that wire, not only am i still not getting the neg. trigger from the rpm switch, my stock tach stops working as well , i un plug it and the tach works again..wtf...msd tech line says my tach signal is weak and i need to buy another part called a tach adapter that amplifies the tach signal to make it work, anyone ever had this problem before? i need VTEC ahhhhhhh......

 

you shoudln't have to use a tach adapter on a honda. its something else.

 

thats what i thought, but i have good power and ground to the box, and i have tried for a tach signal at B15 at the ecu ( ignitor wire) and the blue wire in the 2 pin connector at the distro. (ignitor wire) and like i said that ---- just will not work wtf...

 

bump....someone has had this problem with the msd rpm switch before, SPEAK UP, this ---- sux i need VTEC.....

 

Am I mistaken? ..or does VTEC solenoid not switch ground? I always assumed the solenoid is switched positive.

..and B15 should suffice for tech input to the switch, as it works fine on my shiftkight, and my VAFC, and my datalogging in my ECU. I'm sure it can handle your RPM switch. I think you might have a problem elsewhere.

 

i have a relay wired up to switch the neg. trigger to +12v......but im not even getting a negative trigger out of the rpm switch......---- msd....

 

Off topic, but isnt that a kinda bad way to engage VTEC, I mean, you dont have timing and fuel maps for that.

 

thats what TurboEDIT is for and btw I got the vtec working, bad wire connection....it pulls sooo much harder....

 

You do know you can activate the VTEC solenoid from the PM6 ECu directly right?