Why did I move my ECU?

[Zuffen]

I've had my ECU mounted in the passenger's footwell of my car for close to 10 years and it has never been a problem.

My youngest son is starting to drive the car so I went with him on a few familiarity runs as it's heaps bigger than his Renault Clio R27.

First thing I noticed was I couldn't stretch my (short) legs out in front of me without hitting the ECU behind the carpet.

His girlfriend has long legs and I figured as she will be riding in it I should move the ECU.

I found a new spot that the wiring would reach which is now over 4feet or 1200mm above the ground behind the dashboard.

This entailed passing the wiring trough a 50mm hole I cut under the dash and relocating the ECU, fuses and relays.

All went well until I started the engine.

Nice rough idle that just didn't make sense.

In the meantime I needed the car to be drivable for him to collect the girl as a surprise at the end of her exams.

I inserted a restrictor in the ISCV hose and got the idle down to 700RPM. It drove well and I thought I could live with this solution.

Slept on it overnight and though "no the cars fully electronic and cheating isn't good enough".

Scanned all the diagrams and finally figured out I'd lost the power feed to the ISCV somewhere behind the dash.

Once re-located and reconnected the engine went back to its smooth former self.

Just goes to show how easy it is to make a simple error and make your life hard.

I did make another dumb error whilst doing this.

When I tried to start the engine it would wind over but no sign of firing.

Took about 10 minutes for it to dawn on me the ECU wasn't plugged in!

Plugged it in and away it went.

 

[George_R]

Nice writeup! But your solution isn't complete. Female legs can reach anywhere in the cabin occasionally. I think that's the reason Toyota eventually moved ECU on all its cars to the engine bay.

 

[krayn]

hahaha, good one George. Its so true, Rod probly doesnt find it so funny though..

Nice writeup! But your solution isn't complete. Female legs can reach anywhere in the cabin occasionally. I think that's the reason Toyota eventually moved ECU on all its cars to the engine bay.

 

[Zuffen]

I think the whole episode demonstrates a little more forward planning and writing down some notes would have seen a different outcome.

Too often we see wiring problems due to people not taking the time to document what they are doing and, just as I did, lose a wire or cross a wire.

If somebody learns by this it was worth it.

My son drives a pretty hot hatch as his DD but he just went off to the Gym in my Rover.

This is one car that brings a smile to your face when you drive it. Totally impractical but that's what most of my cars are.

 

[sideshow]

who needs diagrams
just do more of them and everything will be remembered in your head

I don't think its the lack of documentation
I think its the lack or using good electrical stuff

unless u do this day in and day out most backyarders just goto supercheap or repco to get bits n pieces plus sometimes to jaycar to get wire
very often I see 3 different pieces of wire joined together to make a wire reach from
one end to the other

ive started using deutsch plugs and each time I order a few of each side of the common ones well theres a 500 to 700 dollar bill
a lot of people use fuseboxes which have push on spade terminals
I don't ever go near them, I like my fuseboxes with hard wires on them
also I like to sometime put junction power studs under the dash instead of have 5 or more chunky wires running off the battery or starter motor

its the little things u learn the more you do it
I might not have been so great the first time
but the best thing is get everything before u start the job
this way u wont cut corners and if u need another part to make it more reliable then wait and go get it, don't half fix it till next time which might be in the middle of northern teritory

 

[Zuffen]

Jim,

You're spot on.

A (good) Tradesman makes it all looks so easy and the end result is a beauty to behold.

Us pluggers usually get it done in 3 times as long, with 30 times as many problems and it never looks as nice.

But I do like the concept of doing it myself as it gives me satisfaction that I didn't do a "chequebook" build.

Plus it exercises my brain as I don't use a it a lot since I retired.