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Maf And Ecu Guide

Started by firefox · Sep 6, 2008 · 20postsSMF 2010–26

firefoxSep 6, 2008, 1:59 am · #1

You can only use an 86 300zx n/a ECU and any year MAF

if you have an s12 ECU and a 300zx maf  it will run lean and burn up eventually
if you run a 300zx ecu and an s12 maf  it will run rich and will burn your exhaust valves

YOU MUST RUN BOTH ECU AND MAF

All gen 1 300zx run the same MAF sensor as an s12. The difference is MAF housing size
running just a 300zx MAF is like having a MASSIVE air leak past the MAF.  

if you plan to use a different year ecu..  this is how you do that

basically everything is the same except the o2 sensor

our car runs a 17mm Titania O2 sensor which is a 0-1v voltage based o2 sensor
any other n/a ecu besides the 86 runs a 22mm Zirconium o2  which is a resistance based o2

Titania is a 3 wire (4 pin clip).  positive, ground, and 0-1v feed line which runs to ecu  pin # 24

Zirconium is also a 3 wire.  positive, control voltage, and modified voltage
control runs to pin # 115  and modified voltage runs to pin # 24

to run another year n/a ecu you must
1. weld a 22mm bung to your exhaust
2. cut existing o2 wiring clip
3. check for continuity between pin # 24 and the o2 feed line
4. use that line and connect to modified voltage (#24) line from the new o2
5. run a new line from pin #115 to the control voltage from the new o2
6. run existing power to the new o2
7. cap off ground or ground out on the frame
8. DONE

posted image

the turbo ecu can be made to work
i will be covering it later

ArroSep 6, 2008, 2:09 am · #2

Very nice write-up man. Good job

firefoxSep 6, 2008, 4:52 pm · #3
Arro
Very nice write-up man. Good job

sticky?  

i'll add the turbo stuff soon
ArroSep 7, 2008, 5:33 am · #4

No, I'll move it in the "VG30E How-to" section or whatever it's called

FrankensteinZ31Aug 1, 2009, 7:07 am · #5

So say I have an ecu out of an 84 turbo 300zx and I have nistune on it if I wanted to do a rear mount turbo set up?

firefoxAug 1, 2009, 12:59 pm · #6
FrankensteinZ31
So say I have an ecu out of an 84 turbo 300zx and I have nistune on it if I wanted to do a rear mount turbo set up?

read up on nistune shit and you'll see.

you can use like any maf.
Wolf DilworthApr 4, 2010, 1:32 am · #7
firefox
You can only use an 86 300zx n/a ECU and any year MAF

if you have an s12 ECU and a 300zx maf  it will run lean and burn up eventually
if you run a 300zx ecu and an s12 maf  it will run rich and will burn your exhaust valves

YOU MUST RUN BOTH ECU AND MAF

All gen 1 300zx run the same MAF sensor as an s12. The difference is MAF housing size
running just a 300zx MAF is like having a MASSIVE air leak past the MAF.  
if you plan to use a different year ecu..  this is how you do that

basically everything is the same except the o2 sensor

our car runs a 17mm Titania O2 sensor which is a 0-1v voltage based o2 sensor
any other n/a ecu besides the 86 runs a 22mm Zirconium o2  which is a resistance based o2

Titania is a 3 wire (4 pin clip).  positive, ground, and 0-1v feed line which runs to ecu  pin # 24

Zirconium is also a 3 wire.  positive, control voltage, and modified voltage
control runs to pin # 115  and modified voltage runs to pin # 24
to run another year n/a ecu you must
1. weld a 22mm bung to your exhaust
2. cut existing o2 wiring clip
3. check for continuity between pin # 24 and the o2 feed line
4. use that line and connect to modified voltage (#24) line from the new o2
5. run a new line from pin #115 to the control voltage from the new o2
6. run existing power to the new o2
7. cap off ground or ground out on the frame
8. DONE

posted image

the turbo ecu can be made to work
i will be covering it later


Glad I found this.

Wolf
GrantApr 4, 2010, 1:36 am · #8

Glad somebody found it instead of posting another topic.

SlickS12Dec 20, 2010, 5:09 am · #9

Just a note on swapping any z MAF for another, according to autozone, the 84-87 MAF is part number 74-10002 but then it changes to 74-10003 for the later z31 models. 

Couldnt tell you what the difference is mechanical-wise between the two, but it sounds like those would be out of the question as a replacement for a pre-87 ecu swapped car.


Post Merge: 05:17:30 AM / 20-Dec-10

Im currently having bogging issues after swapping to an 86 ecu/maf and am wondering if it has anything to do with the maf.  Had no issues before the swap (besides timing being off)

Weird thing is, the maf I grabbed (86 z) has 6 pins on the connector. 

BUT

My existing maf plug (original 88 se) only has 5 pins to connect to

BUUT

Looking at another se, it HAS the wire Im missing...

Im wondering what the heck that extra wire is for and maybe if thats what is causing these issues.

The extra wire is yellow/red and is at the end of the plug. 
MaxpowDec 20, 2010, 12:02 pm · #10

Yellow/Red going to the 30pin on the ECCS is missing for his maf pigtail as well as there is nothing in the 30 pin on the plug for the ECU. I think someone was dicking around and fucked it up and removed it possibly because I have 2 other SE's at my house to confirm it should be there, as well as a 1988 FSM for the s12 that is saying it should be there.

Any help would be appreciated I am thinking that if we get a 1986 ecu plug and replace the one he has currently with it the car should be working better or at least have all intended stock wires.

Wire is the variable resistance wire coming off the MAF. 88FSM confirms. What kinds of issues could one expect with this missing?

SlickS12Feb 24, 2011, 12:00 pm · #11

another question to add that someone might be able to shed some light on..

Ive been searching for a replacement o2 sensor since my old one is basically useless but since I have an 86 MAF and ECU Im not sure which part to use as a replacement.  Can and 86 model year sensor from autozone work even if it has the three pin connector?  I cant seem to find any with the 4 pin connector on it.  any ideas?

edit:

Just because there is some confusion as to what o2 sensor goes with what maf/ecu combo I ask: which one of these: http://www.autopartswarehouse.com/shop_parts/oxygen_sensor/nissan/300zx.html would work with an 86 MAF and ECU?  My first thought was maybe the first and the last ones on the first page?? 

I could really use the help and my gas tank would benifite a LOT if i can figure this out!!!

thanks  :grinwink:

SlickS12Feb 28, 2011, 10:26 am · #12

**BUMP**

MaxpowFeb 28, 2011, 11:28 am · #13

Just find a STOCK SE one.

That's what you want man. The whole point in getting the year 86 is so that we can retain our stock O2 Sensors.

SlickS12Feb 28, 2011, 11:51 am · #14

And pay $8x.xx for an oem replacement? Comeon man I thought you knew me better than that, Im looking for the least-spendy option. 

Id go pull one from the yard if I wasnt totally sure it wont work but theres so many different companies out there making and selling god knows what.

If possible it would be nice to find a (working) universal replacement.... like the ones in the link.  what do you think about that first one for ~$50?

MaxpowFeb 28, 2011, 12:11 pm · #15
SlickS12 on 11:51:17 AM / 28-Feb-11
And pay $8x.xx for an oem replacement? Comeon man I thought you knew me better than that, Im looking for the least-spendy option. 

Id go pull one from the yard if I wasnt totally sure it wont work but theres so many different companies out there making and selling god knows what.

If possible it would be nice to find a (working) universal replacement.... like the ones in the link.  what do you think about that first one for ~$50?


Yeah I know better. That's why you can't buy cheap shit. Throw 80 at it and not have to do it for a long time or throw 40 at some junkyard/cheapo that doesn't fit the application correctly, never have proper air/fuel and never run correct.

I'm all about getting it done right as cheapy as possible, avoid the jank. That never went well for us ;).

IE: Quicksteel.

Post Merge: 10:11:50 AM / 28-Feb-11

parts numbers are parts numbers by the way, its not gonna be more just because its for a s12.
SlickS12Feb 28, 2011, 4:59 pm · #16
Maxpow on 12:11:21 PM / 28-Feb-11
IE: Quicksteel.

hey that shit worked! lmao the only thing Im hung up on is the fact you can use an se o2 sensor w/ 86 components, why not use an 86 300 one??  it just makes sense it would work and it is oem (kinda w/ mods) and CHEAPER! ;)
MaxpowFeb 28, 2011, 5:27 pm · #17

you're positive its the same threading and whatnot?

Try it. Then we'll all know.

silvertonFeb 28, 2011, 5:56 pm · #18

Just out of curiosity, what kind of gains can be seen from this?  A bigger MAF does flow more air, but will it be more of a placebo effect?  Or does doing this make running nistune easier and that's the purpose...?  I see they have the z31 listed, but not the s12...

MaxpowFeb 28, 2011, 8:55 pm · #19

I have 6 setups for sale by the way.

Ju_S12_TurboMar 3, 2011, 2:42 am · #20

I run the same set up on my car, I had to run hella timing to get it to the right marks. But I passed CA smog (Sniffer/dyno) with it on. I had a friend over look the cone filter and missing Charcoal canister.

Edit: also I am pretty sure the s12/300zx o2 are the same BUT the wire length is different (300zx is shorter)