Gen 2 3SGE to gen 3 3SGTE conversion

Heya,
 
I've got a gen 2 3SGE MR2 I'm currently in the process of swapping a gen 3 3sgte into. The gen 3 is currently having the block machined with ARP rod bolts and studs installed. After that it's assembly and swap.
 
I've got the ECU, engine loom, fusebox and what I believe is a completely uncut gen 3 body loom (terminates at kick panel I think).
 
Is the best way to progress with the swap to completely swap the gen 3 body loom and fuse box in? With this done, what rewiring is required to make it work? I understand cable driven speedo won't work, I can deal with that. Does anything need to be done with the kick panel electronics?
 
I've attached a list of my ECU pinouts. Should all match up and work, asides from engine bay cooling fans I don't have anyway (I will set up engine bay and IC fans).
 
Thanks for the help!

5SGTE
The ecu will still need a speed input, not sure if you could simply use the output from a mechanical cluster.

What does the ecu actually use the speed input for? I don't have abs, traction control or cruise control.
 
As I have a mech cluster my speedo won't work until I find an electronic dash to use.

Eric
There is a wire in the boot that comes from the cluster. Its on the grey plug, pretty sure it's purple. I used this for my 2GR swap.

I've got the pinouts so I know which pin SPD is, I just don't know what the ecu would use it for except for speed limiting. If it'll work fine without it I'm happy to sort it out later- I can't leave it where I'm doing the swap excessively long.
 
Plan is to swap a 93+ dash in later to fix the speedo. Probably gps/phone app in meantime

Mrskylighter
The ecu may use the SPD input to help determine what the idle should be. From memory if you shift into neutral and coast it will idle around 1000rpm but if stationary it will idle around 750rpm.
 
I might be completely wrong though haha

Oh interesting, I didn't think of that. So it'll probably run without it, but may throw codes?

Eric
As above, I believe the Toyota ECU's use it for idle.

Its only one wire, so you might as well hook it up

I'll definitely hook it up. They're in the same pinout on both ECU's anyway.

But that wire won't do anything until I get an electronic speedo dash, I just wanted to know if it would work in the meantime while I find one

The output from the mechanical speedo cluster to the ecu will work fine. It matches the output from the electronic gearbox speedo drive that normally goes straight to the ecu and electronic speedometer in a Rev3 car.
 
I have a Gen 3 3sgte with factory ecu running in an AW11 with a mechanical speedo. No issues at all.