Hey Guys -
Can someone tell me how to correctly wire the Z32 MAF into a 99'-00' when using a Power FC? I've been all over the internet and all I can find is the wiring for the 92'-96' MAF. This is a 4 wire MAF on a Version 6. Here's what I've got on the OEM MAF:

Yellow/Green = 12V (Sensor Power)
Black/Green = Ground (??)
Green = AFM Signal (??)
Blue = 5V (??)

Voltages were measured with the key on. The 5V blue wire doesn't makes sense as the MAF should only require 12V/ground/ouput to function. However, with the blue wire cut, the car will only fire and run for a second with the OEM MAF/Power FC. Any help would be greatly appreciated!!

Ryan

 

Have responded to your pm

 

Is there a better MAF for 99-00.

 

yes Q45

 

I agree... Ive been using a Q45 for the past 3 years with out a hiccup plus it’s a 90mm diameter compare the 80mm of a Z32

 

At least on my J-spec, Version 6, the Z32 is a better fit. The 80mm Z32 is a drop in replacement where my OEM airbox was. Apex makes an adapter/air filter which puts everything back where it should be. If I went with the 90mm Q45, I would have to buy some additional couplers to neck it down. The inlet on my turbo is the factory 60mm, so I don't really see the point (other than the Q45 MAF is cheaper).

For tuning, I'm using a Datalogit and my Innovate wideband air/fuel gauge. I'm looking to purchase the Gizzmo knock amp/headset for rolling road tuning. For right now, I'm not planning on advancing the timing up to the ragged edge. Just a nice conservative tune to get the car running sans the flaky OEM MAF.

So back to wiring, any thoughts? I'm going to give the Z32 a shot, minus the blue wire this morning and see what happens. The blue wire has 5V on it, I don't necessarily want to send that to ground. We'll see what I uncover.

Ryan

 

sorry said I would dig out the wiring info I have

300 ZX MAF connector has 6 pins A-F:
A - Not Used
B - MAF Output Signal
C - Gnd
D - Gnd
E - +12V
F - Not Used

hopefully with a volt meter you can find the matching wiring on the OE plug?

just don't connect the two grounds together and on the OE wiring.. does strange things

Simon

 

Success!!

OK, here's one for the archives as I've yet to see it unearthed via search.

99'-00' STI Version 5/6, J-Spec MAF has four wires:

Yellow/Blue = 12V sensor power
Light blue = 5V NOT USED, do not ground, just cut and cover with heat shrink
Green = Airflow signal back to ECU. This easily discovered once you pull back the electrical tape from the OEM connector. It's shielded, OEM's always shield the AFM signal wire.
Black/Green = Ground. I guessed on this one as every Subaru wiring diagram before and after mine denoted ground as black/green.

Z32 Maf harness. This is an easy one as a google search will turn up a ton of links as to correct wiring. Anyhow:

A: Not used.
B: White shielded wire. Connect to Subie's green wire.
C/D: Black wires. Grounds. Twist and connect to Subie's Black/Green wire.
E: White UNshielded wire. 12V, connect to Subie's Yellow/Green wire.
F: Not used.

I hooked everything up as shown above, selected Option "3" in the Power FC (80mm VG30 MAF) and she fired right up. Air Fuel's are in the high 12's which is consistent with a cold start. The car free rev's fine and airflow rises with a stab of the gas. Of course they'll be some tuning to get it dialed back in but it looks like I'll be good to go.

For the techies out there... read on. As for the blue wire, I have two theories. Measuring the resistance at the OEM AFM, I show 4.6K ohms between pins "B" and "C" (blue & black/green wires). This could be one of two things.

I could be measuring the voltage drop internal to the MAF circuitry. This circuitry may utilize the 5V (fed FROM the ECU) along with the 12V, for proper operation of the MAF. This makes sense as even the Power FC won't run the car with the blue wire disconnected.

The other option, which I found referenced on a Legacy bbs, is that the blue wire could identify to the ECU whether it's running say...a JECS or Hitachi MAF. IE: If the blue wire is "grounded" within the MAF, it's identified as a Hitachi MAF. If the Ecu sees say...4.6K ohm of resistance, it could identify it as a JECS Maf. With the pin open, it's just confused .

That's my theory anyway. Irrelevant to the three paragraphs above, the wiring should get you running again.

Cheers

Ryan

 

i have a z32 maf spare if anyone needs one.

 

Not sure if anyone can help I've Fitted a z32 & have switched over in the pfc ecu to the correct setting number 3 using datalogit . I'm running 440cc injectors & afr's are super lean at idle I picked the values vs volts up to 200. it's not correct though. Does anbody have these values that I need. Also do airflow curves need adjusting??



Any help would be greatly recieved..

J

 

Bump

 

I've just had the Z32 Nissan Maf this fitted to my Version 5 Type R due to it eating 3 standard subaru MAF's in 6 months after my 2.5 conversion :s

This info has been copied form wrx.com.au, and thought it may be useful to post here incase other memebers were looking for this info

PS
Big thanks to the scoobyclinic boys for fitting the MAFand remapping my motor
-------------




FITTING A Z32 TO 99/00

What is an AFM?
Afm stands for ‘Air flow meter’, occasionally known as MAF. Its what the computer uses to measure the quantity of air entering the engine to determine how much petrol to inject and how much timing to apply.

What’s a Z32 afm? Why would I need to upgrade to one?

The z32 is a very common upgrade with Nissan cars, 200sx's, GTR Skylines, 180sx's etc.
They are generally upgraded on those cars more since they support larger amounts of power compared to the stock afm.
Subaru Wrx owners usually upgrade to z32 to remove the problematic stock 99/00 afm. The quantity of engines these afm's have taken is endless.

How does at faulty Afm cause the engine to detonate/ping?


If it reads less air than is actually entering the engine, the ECU puts less fuel in, and while it also sees less air it also assumes less load and adds more timing, both bad, the engine knocks and boom!


z32 AFM onto 99/00 what do I need?

First of all, you need a Apexi Power fc for this modification.

The Nissan z32 is an 80mm afm and the 99/00wrx uses a 90mm, so unfortunately it won’t bolt straight up. The bolt spacing is wider on the 90mm afm aswell.
The 97/98 wrx uses an 80mm afm, so you can just use the parts from that model on your car.


Option :
My97-98 Airbox Lid, don't need the bottom as its the same part number as 99/00.
My97-My98 Aps Cai
Modified My99/00 Aps Cai (need to drill 4 holes for afm)
My97-My98 Pod filter with (80mm adapter around $15 Autobarn)

Option for other side
Use existing 99/00 inlet + Some silicon used as a spacer.
My97/98 Inlet pipe 80mm
Aftermarket Silicon bend 80mm


How do I wire it up?

The best way to wire one up is to splice into the factory loom. A lot of people just cut the factory plug off which is Unnecessary and pointless. Splicing leaves the standard plug still attached, so you can revert back if need be.



Once wired up, what now?

Before trying to start the car, you need to change the settings on the power fc itself.

On your hand controller go to settings\ airflow highlight option 3 which should read VG30.

The car should start, however you will need to get the car on the dyno for a slight tweak tune to make sure all is good with the new afm.


Why not use the Q45 afm, isn’t that a straight bolt in?

The voltage tables on the Power FC need to be tweaked before you can run this afm, so that means the tuning shop needs the power fc laptop tuning software, you can’t tweak the voltage tables via the hand controller itself.

The Q45 AFM is very large and can cause a lot of tuning issues on small engines at low rpm. The q45 can be fitted and can work with wrx, however, most tuners cant get around the fact that the same cells used around idle, are used on light cruise.
So for example: when the idle is tuned right, the light cruise is rich, and when I say rich I mean like 12 afrs. Should ideally be 14.7, then if you fix the light cruise, the idle will go very lean. So in a nutshell, you can fit one up, but don’t expect good fuel economy while cruising, 02 sensor feedback helps, but its far from perfect.

Some tuners can however tweak the voltage tables to cure this issue, but doesn’t work on all setups and most tuners will recommend to steer clear of this afm.

Also Many people have thought to believe that because the q45 is 90mm, it supports more power than the z32 but this is false.

 

Maybe 5 volts is for self clean of afm that I think some afm s have?