Help with Tacho wiring in conversion

[Wizzard]

Hi all,

I have just about finished putting a Toyota 4E-FTE into a Mazda 121 and have all the dash wired up except for the RPM. I believe the issue is similar to the 1JZ-GTE into a Supra 2JZ-GE conversion I have done in the past. The Mazda reads a high voltage pulse from the dizzy every time a spark happens (or its fired), but the Toyota uses a Igf signal back from the igniter (if similar to 1JZ then its a 5v signal). So I am guessing this is my problem.

Do you think it would be as simple as the Supra dash conversion where you link out the resistor in series in the dash, and then the low signal can drive the RPM from the Igf signal?

See I searched!
http://www.toymods.org.au/forums/tec...gine-swap.html

This is the mazda wiring...
Mazda.jpg

[wilbo666]

Usual way is to make and install a tacho booster...

I.e.
http://www.toymods.org.au/forums/tec...o-booster.html



Cheers
Wilbo

[Wizzard]

Hi Wilbo,

I have done my normal trick, asked the question then pulled stuff apart! I have to do it the other way Seems that the tacho has a series 33k resistor (seems to be popular) current limiter on it

I am just going to solder a 1k resistor in parallel for now and see if it works...I will build the tacho booster if I have to.

Justin.

[Wizzard]

Didn't work, have to build the tacho booster

[dumbass]

I've got afew different tacho boosters
They might work but cost abit
If u can tell me what signal u need then I can tell u if this might work
I can look at it all for u if your in brissy or gold coast area but by time I come out and get it all working
Could easily cost 200 to 300 bucks
In the end I just tell people to send tacho to instrument guy to mod it so it works of low signal

[Wizzard]

Thanks mate but I am an electronics guy and just checking out all the solutions. Thanks for the offer though. I will be trying the booster stated here first and if doesn't work I will look more closely at the tacho itself and see how its components are set out.

[Wizzard]

Ok just giving feedback.

Tacho booster works absolutely fantastically for a 4EFTE (off IGn) to Mazda dash. Very happy. At first I thought it was out a bit (reading too high), but then hooked the laptop up to the eManage and saw it matched...found out a throttle cable adjustment was required and hey presto!

Thanks to whomever thought this one up originally! $8 in total with a reused relay (12v 40A).

[alexlegault]

good luck man