Hi guys, just picked up an early '94 import. Mechanically it appears all standard apart from an exhaust. I havn't checked but at most I believe one cat has been deleted, possibly not though. I am having a couple of issues with the car which I'm trying to iron out relating to the smoothness of the drive/boost. At the moment no investigative work has been carried out so this could be as simple as a loose hose or maybe coilpack etc.

While I'm getting to the bottom of these things and having servicing work carried out I am trying to decide whether to delete the currently fitted AFC. These are the only pics of my model I could find:








Do I need this fitted to an otherwise nearly-stock vehicle? Setup incorrectly is this device capable of doing serious damage? I just don't see the need to keep an 'air flow converter' with no real mods that require fuelling alterations.

Any insights or views appreciated.

 

yes if set wrong etc.. no need for it no..

appears to have been set to not effect anything at the mo.. but removal best imho.

Simon

 

oh and if it is a slight hessitation / pulse on boost then it is probably the coilpacks or plugs.. get new plugs in it

Simon

 

Hi JGM, cheers for reply.

I acquired those pics from Yahoo Japan... mine is fitted and was set to somethingorother. I gradually backed it off one click at a time until it was back at 0% i.e. not doing anything. If anything the car felt a touch perkier. Will be removed in due course

 

 

Standby for more informationz:

After running well on 0% for a while I decided to unplug the unit. Stopped, keys out, unplug the Apexi, startup. Idle was very lumpy and erratic... eased the clutch out in first, extremely uneven power/no power etc. clearly not happy, turned the car off within about 10 feet, stopped, off, plug back in and away.

Next step was to find out for sure what this was doing so I followed the Apexi wiring back to the ECU to see for myself.

My ECU:



To recap the Apexi has four wires; red, black, yellow and white. All four of them are spliced into the group of wires (in a variety of ways) that are on the right-hand plug going into the ECU.

Red:


The red wire from the Apexi is the one going into the top-left of the 'Y' connector on top of my thumbnail. It looks like this is spliced into the original Subaru wire which is yellow with blue stripe and silver dots. This yellow/blue/silver dot wire goes into the plug on the top row, second in from the right. The first in from the right looks vacant.

Black:


The black wire from the Apexi looks to have been spliced in in a similar manner with a 'Y' connector. As we look at the picture it is the 'Y' connector on the left hand side. Again, from our viewpoint the 'Y' looks upside down; the black Apexi wire is coming out of the left-side... you can see follow it back and see it group up with the other three Apexi wires. The Subaru wire it is spliced into is also black, it has silver dots and goes into the plug on the top row, second in from the left.


The yellow and white Apexi wires appear to differ from the black and red; black and red look to be spliced in i.e. the original wire is still in the circuit but is being tapped into... the yellow and white look to be actually cut-in, that is the original circuit has actually been altered.


Yellow:


The yellow Apexi wire here is shown connected directly to a Subaru ECU wire... It goes into the ECU plug on the top row, third in from the left.


White:


I have no solid information on the white Apexi wire. It is cut in to a Subaru wire (also white) and disappears off into the loom/taped up.


The control unit itself:
This picture is a generic library pic, as seen in my original post:


Here is my actual unit:


The 'Car Select' seems to be set to 'A'?


My guess:
The black and red are spliced in only as a power source; the yellow and white are the ones doing the work here. It looks like the Apexi is only acting on whatever function is dealt with by the (original) white Subaru wire going into the top row, third in from the left.

Original wiring - note white wire going into top row, third in from the left of the right-hand ECU plug:



My guess at how this is wired now:



So... any takers to confirm/correct? What does this white wire govern?

 

the white wire is maf signal..

wiring diagram here

unply red and black, unplug yellow and white and connect white original to original... if lucky the plugs connect together

you are correct

Simon

 

Awesome, many thanks!

For the record I've made a tidier diagram, anyone feel free to save it off for future use/archive:

 

have removed a fair number when installing a replacement ecu to map the car etc.. far worse is removing a piggyback ecu.. several more wires.

Simon

 

I have one of these aswell but its slightly different, it has a type select section with 8 jumpers, these are set to

1 = up
2 = up
3 = down
4 = down
5 = down
6 = up
7 = down
8 = up

.

Has anyone got any idea what these should be set to for a 95 uk turbo, this came off a s14 nissan? I have set the car select to A but i have no idea about the jumpers and i cant find any info on this.

Any help would be appreciated