ae86 tachometer with standalone ecu

[Grant #2]

I have been driving without a tach for about a year now and would like to get the thing going. It worked when I had the 20V with oem ECU, but that setup was pretty slow.

What do you guys do to get your tach working? I have been told the voltage output on my stand alone might not be enough to drive the tach? Do I need to sire in a pull up transformer? If so, any idea how much voltage the tach wants to see? My output is probably 5v or 12v coming out of the stand alone.

Thanks!

[Skylar]

search gze tach/o mod. Do that then hook a 12v pull up resistor to the tach line coming out of the VEMS.

[Stain]

what ecu? what ignition system?

if you still have a single coil you can run the tacho off the neg terminal like normal.
if uve got a coil over plug or coilpack setup and a aftermarket ecu like an adaptronic the tacho output signal isnt compatible with the 86 cluster.
but you can make up a tacho booster out of a relay to put in-line to give the correct signal.

[assassin10000]

5v or 12v is not enough voltage to trigger the AE86 tach


Many do the tach booster, see here: http://www.toymods.org.au/forums/showthread.php?t=22574

The MSD 8920 tach adapter does the same thing in a neat package (I have one for sale, if you want it I might be in the bay area this weekend and can bring it to save a few $ on shipping).



Andrew

[Grant #2]

Andrew, how much u want for it?

Do you know what kind of voltage toyota tachs need?

Thanks for the suggestions, I'm running wasted spark so actually I probably will have to do the gze mod anyways?

[assassin10000]

Wasted spark shouldn't matter if your ECU has an output. The ECU should output a signal for EVERY spark event.

I think the tach expects to see between 20-40v back EMF voltage spike from the coil negative when it fires, could be higher but that's what I recall. $43 which is what I paid for it, it's brand new I just opened the package to look at it.

Andrew