S12OC UK Forum - S12 ca18det brief pointers

S12OC UK Forum (http://nissansilvia.co.uk//index.php)

- How-To section (http://nissansilvia.co.uk//forumdisplay.php?f=6)

- - S12 ca18det brief pointers (http://nissansilvia.co.uk//showthread.php?t=849)

S12 ca18det conversion brief pointers

This is a list of pointers for someone who is familiar with basic mechanics

--------------------------------------------------------------------------------

When fitting the ca18det into a ca18et s12 you can use the:-
same s12 gearbox and bell housing,
same s12 engine mounts in exactly the same location.No mods needed
same s12 car loom.
You need the s13 ecu,loom and loom ancileries ie dropping resistor for the injectors and a s13 power transister for the coil packs which you also need and the 3 green top relays from the s13 engine bay to join your car harness to the ecu harness. These relays are used for the fuel pump and ecu.
s12 power steering and alternator can be used. Cut a chunk out the s12 power steering pump bracket to clear the wider det head or find a s13 bracket
The s12 exhaust is compatable. Use the s13 manifolds and turbo & downpipe. You could use the s12 turbo and downpipe but it really is too small#

When wiring in the s13 ecu loom you will see that there is a big plug spare by the ecu and another further down the loom near the air flow meter.These used to connect to the s13 car harness.You need to reconnect some of these to your s12 system.

The connections you need to make are listed below with there wire colours.
BY AFM

Black / Pink stripe
Fuel Pump Relay

Red / Black stripe
ECU Relay

Red
ECU Backup Power

Black / Red & Blue / Red (Note: connect 2 wires to 1)
Main Ignition Power

Black / White stripe
ECU Power

Brown (to O2 sensor)
O2 Sensor Power
Any 12v switched source

white plug

Yellow / Red stripe
Tachometer signal

Orange
Ignition start

Black
Ground

Blue / Black stripe
Water temp signal

The s12 and s13 have 2 looms. A engine loom and car loom. all you essentially are doing is swapping the engine loom over and then powering it up.
You can use the s12 fuel pump but its advisable to uprate it as it will probably run lean under load/boost. You need to change the wiring for the pump round so that it has the new ecu + feed via a green relay and a constant body earth rather than the old s12 wiring that was earth switched.

good job !
Thank you pukka ;)

i still cant get the s12 tacho working in mine. my tuners tried everything.

had to use an after market rev counter.

any ideas...

use the S12 gearbox ;)

the gearbox has nothing to do with the tacho toytoy, thats the speedo :D

I assume its the Rev counter your on about, excuse my lack of tech jargon. If this is the problem then its a sensor located just by where the air intake pipe joins the air flow meter. there is a sensor attached to the loom here & it tends to get corroded. Check this or replace, I think this should cure your problem. I think Silviagod has a pick of this somewere on his web pages.

this was posted by Sam on club-s12 and we both need help.

If somebody could provide us with a pinout instead of colours, that would be very much appreciated.

Quote:

ok, here is the deal. Indy pmed me today asking me about the white plug that comes off of the 18det harness near the plug for the ecu itself. I went back using the old original write ups colors of what should be coming off of the white plug, wrote down what came off of my white plug...and here is where we have an obvious problem. Now I am thinking that what isnt off of the white plug must be spliced into off of the ecu plug itself...anyways, if anyone actually knows what is supposed to be done, that would be nice....cuz i am kind of speculating at this point. Anyways, here is the original pm convo with indy and I Including the wire colors of what is on my plug, what should be on my plug, and pics of everything.

Ok, here is what I did, I went from the top row left to right and grabbed the colors off of every wire and this is what I came up with...let me know if you have the same.
http://i16.photobucket.com/albums/b4...u/PA130002.jpg
note the indenture for the plug is the top...

grey/blue stripe
green wire
blue/red stripe which is the main ignition, but it doesnt combine with another wire like the original write up said it did.
blue
orange
black, slightly larger gauge wire
black, it maybe possible ecu power...
http://i16.photobucket.com/albums/b4...u/PA130024.jpg
there is 2 silver like stirpes near my finger, and the ecu power is supposed to be black/white striped
blue/silver stripe
yellow/green stripe-ac relay
grey/red stripe
red-ecu power back up
light green
black (again possible ecu power, has the same stripes on it)
white
blue/black stripe
yellow/red stripe

for more reference...here is what the original write up said should be there...

Black / Pink stripe
Fuel Pump Relay
missing in action from our plugs

Green / Orange stripe
Transmission Neutral Sensor
mia from our plugs

Red / Black stripe
ECU Relay
mia from our plugs

Green / Yellow stripe
AC Relay
mia from our plugs....but who needs ac?

Red
ECU Backup Power
mia from our plugs

Black / Red & Blue / Red (Note: connect 2 wires to 1)
Main Ignition Power
i didnt see it combine anywhere...but maybe your supposed to combine them? if so which black do you combine it with?

Black / White stripe
ECU Power
2 possible wires, but i am not sure which, or if they are possibles
Blue / Green stripe
AC Relay
mia from our plugs

Black / Yellow stripe
Idle Air Control Valve Power
mia from our plugs

Brown (to O2 sensor)
O2 Sensor Power
Any 12v switched source
I didnt see a brown wire anywhere near my plug

I am prolly going to post this onto the 18det tech forum and see if we can get any response from anyone there....I am thinking tho that what isnt on the white plug has to be pulled off of the ecu plug, but i could be wrong.

Indy

Quote:

it's not the ECCS connector though. It's the white plug beside it. I havne't found a pinout for that yet.

ME

Quote:

Actually, when i first started looking at my harness the colors people gave didnt match up either. I am thinkin that tho if your colors dont match use the ecu pinout and forget the colors. I am thinking its possible that nissan changed harness wire colors on some of the 18dets. That would atleast explain why yours and mine colors dont match anyone elses. The ecu pinout should be the same tho. Anyways, let me know how that works out.

Indy

Quote:

hey sam, I was gonna wire up my car today but ran into some problems.

The wire colours for the white plug on my ca18det harness dont' match up to the ones everybody is using for some reason.

The main ones I'm concerned about are:
ECCS Relay
ECCS backup power
Main Ign power
ECCS power
O2 sensor power wire

The others like Tach and Temp and start signal are there though.

Anyways, you said yours matched up right? Could you do me a huge favour and tell me which wires are which on the plug? Like just let me know like...

"Looking from the back(where the wires go INTO the plug) the ECCS relay wire is on the top row, third from the left."

If you could tell me which ones they are that'd help me so much man. And also, just in case, could you confirm at least the start signal wire as well? the others that are "there" aren't as important as the start signal, and I wanna make sure that's the right one.

If you could do that for me, I'd owe you a big one.

~Tim

I really cant understand all this Jiberish.

What wiring have you got left to do exactly? Thats all you need to say

no worries jon, we've got it sorted out.

basically, the wires for the ECCS relay, IG power, etc.. aren't on that white plug you were describing. They're on the two plugs that are in the engine bay.

The white plug only has the start signal, and the wires for the gauge cluster sensors.

1st place i have looked to do ca18det conversion and there is so much info here!! good job

leo