tach output not working with tach anymore.

General Megajolt Questions and Answers

Moderators: JeffC, rdoherty, stieg, brentp

Post Reply
itzdave
Posts: 1
Joined: Fri May 25, 2012 4:43 am

tach output not working with tach anymore.

Post by itzdave »

Hello. I have megajolt installed on my 87 honda accord with 45 dcoe webers. The car used to run just fine, but I did a wire tuck in the engine bay (wire by wire, one at a time) and now the tach isn't getting a signal so the fuel pump isn't turning on.
The wire I used was the tach output from the megajolt unit, going to a blue wire that used to connect to the oem coil.
The car runs fine, laptop shows rpms and load, all other outputs from the megajolt work fine (shift lights and hard rev limiter).
I'm getting a constant 12v from the tach out wire when the ign is turned on, and when the car is running. What have I done wrong? Could I be missing a ground or something? Thanks in advance.

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

It's hard to say without being able to see the signal. Do you have an oscilloscope to see what the output looks like?

You can also connect to the IDM output of the EDIS module - it's like a 12v tach signal.

Please let us know what you find out.
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

Post Reply