rd28 to td42 engine conversion tacho wiring

[Benno7]

Hi guys Im in the final part of my conversion and I cant figure out how to wire up the 4.2 tacho sensor to the 2.8 loom. as the 4.2 sensor has 2 wires and the 2.8 loom has 3 wires.
Any info will be helpful thanks.

[bexi]

Hey benno,
Do you have a thread going on the whole conversion?
I have a complete GQ with td42 and crappy body and am thinking about buying a GU with a cactus 2.8 in it but am just trying to get more info on doing the conversiona nd how difficult it is
cheers
bexi

[Benno7]

Nah not yet mate but I will as soon as its all finished.
Its not a hard conversion if your handy with tools but with putting it in a GU I know you need a GU gearbox.


By the way tacho all sorted.

[bexi]

did you try it with a gq gearbox first to see what would happen/how much of the floor you'd have to cut out?

Also, how did you sort the tacho out?

[Benno7]

Mines a GQ

[bexi]

oh ok ... so what's the trick to the tacho wiring?

[Benno7]

just cut the plug and used two wires out of it. Thought id give it a go and it worked so all good.

[bexi]

ha! ...so the 2.8 harness has 3 wires and the tacho sensor on td42 has 2 wires????? is that correct?
...then you just did trial and error with the wires? do you have the colours?

[Benno7]

I did'nt take to much notice of what colour wires I used. My 2.8 harness had 3 wires But a mates one only has 2 wires. And yeah the TD sensor has 2 wires.

[zacygtr]

hi did this conversion not long ago took 5 days to complete although im having trouble with wiring

out, RD28 (GQ RX2.8)

in GQ TD42 added the turbo after and tricked the pump

struggling with dash

speedo and tacho do not work

any ideas on what i need to do i am still using the 28 lume and dash was told i can get it working with the 4.2 just unsure how

thanks
zac