CRXtreme20

1. i put a b16 in my rex and before i did it i noticed the tach was real jittery and would jump around and wasnt consistint. well now that the b16 is in there the v-tec wont work. how do i fix the tach signal problem? i do have ful MSD with an external coil. can i tap off the MSD box and run it to the computer????

2. a while back i remember reading where i could get the eoru diamond clear front corners... but cant remember where? also i need the bumper lenses as well.

thanks for the help in advance

1stGenCRXer

First off, where is your tach pulling signal from right now? If you aren't pulling your tach feed off of the MSD box, then the MSD is very likely screwing up your readings if you're still pulling off of the coil. The tach feed under the hood is a blue wire that goes into the main chassis harness [if you didn't already know that].

If that's all gravy, and the wire is fed by the MSD box, then the ECU is already getting a direct feed off of the MSD, which leads to some more questions:

Do you have an aftermarket stereo equipment [specifically, amps]? If so, you may want to look into routing your power cables a little differently, or replace the tach feed wire with an EM shielded wire.

Also how long ago did this start happening?

p'sH23Acoord

Also if you have an engine light on or the speedo doesn't work the ecu won't allow vtec.

katejetta4

check your oil, vtec won't work if you low on oil

CRXtreme20

sorry this took so long to get back... no the tach signal isnt off the msd, so in theory if i just replaced the tach wire going to the motor and to the computer with one from the MSD it would all be good right????? and i have a wire going to the external coil off the MSD box and if i splitt it two MORE times will this effect the strength of the signal? will it be too low for the computer to read it????? thanks again

1stGenCRXer

Do NOT give the tach more than one signal, and with an MSD ONLY use the tach output on the MSD box, do not try to give the tach a signal from the coil anymore.

CRXtreme20

im not giving it two signals ... i said if i was to give it the signal from the MSD and not the factory wires. the MSD box only has one tach output, so can i split off of that wire a total of three times and the strength still be ok??? what type of signal is a "tach signal"? like volts or what, does it pulse or stay constant, if i knew these things i could better fix the problem. thanks for the input

1stGenCRXer

The tach signal is an on-off voltage frequency. All you should really need to do is to take the original tach lead that went to the coil and plug it into the MSD box, the wiring harness in the car should take care of the rest.

CRXtreme20

but the wire harness in the car is what i think is grounding out somewhere... thats why it is gittery while in motion, at idle the tach will work but when i go it is real jittery. do you know what color the wire on the coil so i can be sure thats the right wire going to the MSD box? but remember the tach was doing this before the motor swap.

1stGenCRXer

The tach lead is normally a blue wire.