MSD into vtec...

Okay, my buddy and I followed the schematic for wiring up vtec in my 91 crx with the msd rpm switch and a relay .... now my tach doesnt work :banghead: ... we followed the directions to a T. Any ideas? Plus how can we tell if vtec is engaging? Thanks.
Vince

You should feel it and hear it engage...If not, you can always put a light from the solenoid wire to a ground and when it engages the light will come on..

Okay, now for this tach problem....

check you connection... and I actually ran into the same problem with other hard ware attached. So I started to use the plug on my MSD A6 box

BTW I highly reccomed and P28 and OBD-1 well worth the money

BTW I highly reccomed and P28 and OBD-1 well worth the money

A great investment.

the minimum I would do to activate vtec is w/ a vafc.
I hope you're not really expecting a noticable gain in power w/ your ghetto rigged msd switch. The motor is not using the correct fuel and ignition tables. If I were you, I'd convert to obd1 which is the simplest. If you have the ability to learn...I'd look into something like BRE, which is free software and cheaper in the longrun, but more complicated to fully understand.

like bambam said, RPM switches are ghetto as hell. One step up from a toggle switch. Like prehistoric time honda swap shit.

Anyway, if you just did a sohc vtec swap, you really wont hear or feel vtec hit, its more of just a increase in the powerband. vtec on a d is nothing like vtec on a b.