S14 Sr Running pinned at rich, wont lean out.

[Destructodc74]

My s14 sr20det was freshly machined by a shop and replaced with all new oem internals. i never saw the motor run before that but after i installed it in my s13 chassis it just doesnt want to cooperate. everything is pretty much stock with normal bolt ons and a fmic. but i am running a z32 maf with a apexi safc2 to compensate. i had it set for the z32 maf using the safc manual but it still runs pinned at 10 on my wideband. sometimes it will jump around as high as 10.8 or so. it has a rough idle as well most likely because of running super rich, i swapped out the maf for my buddys z32 and the same thing happened again, any ideas? sorry for the huge paragraph.

its a zenki s14 sr20det btw. could i possibly have the wrong ecu or wiring harness for my motor and this be the cause? my friend who knows how to tune with the safc tried leaning it out and said the safc wasnt affecting anything no matter what he did. and i checked the safc wiring today and it was right.

[Sileighty_85]

Verify the MAF was wired correct,
Almost sounds like you have the 12V wire swapped with the 5V signal wire

[Destructodc74]

Verify the MAF was wired correct,
Almost sounds like you have the 12V wire swapped with the 5V signal wire


thanks, i re wired the maf according to some diagram i found online so i thought it should be right but i will double check that for sure.

[slider2828]

Check your fuel pressure and any leaks in the fuel rail.....

[Z U L8R]

a bad coolant temp sensor can make it run uber rich like that. (2 wire for the ecu)

if you look at the maf plug and the wires are facing your belly. the two humps will be on the top and the three humps will be at the bottom and on the maf it'll say

FLOW ===>

it has 6 slots so in order from left to right it should be

1=empty
2=maf signal
3=ground to chassis
4=ground from ecu
5=ignition 12volts
6=empty

make sure your grounds aren't twisted together because that's not correct and that too can cause the car to run jacked up.

also double check your safc wiring that the white wire goes to the maf sensor side of the maf signal wire and the yellow wire goes to the ecu side of the maf signal wire.

also make sure your brown and black grounds aren't twisted together either. they're supposed to be spaced apart.

the safc settings should be on hotwire 2 in 5 out, calib 1:1

when you back out of setting the car select make sure hotwire is still highlighted. if you go back and you set the hotwire then scrolled down to like karman or pressure then you're setting it to karman or pressure. a lot of people do this for some reason.

oh, i've had a few n62 maf's run better at 4 in instead of 2 in..... i have no idea why but that's how it went down. it's a night and day difference so if it doesn't really change much then leave it at 2 in cause you have a different problem.

hope that helps, gl

Dave

[Destructodc74]

Check your fuel pressure and any leaks in the fuel rail.....

good idea. theres no leaks for sure but ill check the fuel pressure, what is stock supposed to be any idea?
a bad coolant temp sensor can make it run uber rich like that. (2 wire for the ecu)

if you look at the maf plug and the wires are facing your belly. the two humps will be on the top and the three humps will be at the bottom and on the maf it'll say

FLOW ===>

it has 6 slots so in order from left to right it should be

1=empty
2=maf signal
3=ground to chassis
4=ground from ecu
5=ignition 12volts
6=empty

make sure your grounds aren't twisted together because that's not correct and that too can cause the car to run jacked up.

also double check your safc wiring that the white wire goes to the maf sensor side of the maf signal wire and the yellow wire goes to the ecu side of the maf signal wire.

also make sure your brown and black grounds aren't twisted together either. they're supposed to be spaced apart.

the safc settings should be on hotwire 2 in 5 out, calib 1:1

when you back out of setting the car select make sure hotwire is still highlighted. if you go back and you set the hotwire then scrolled down to like karman or pressure then you're setting it to karman or pressure. a lot of people do this for some reason.

oh, i've had a few n62 maf's run better at 4 in instead of 2 in..... i have no idea why but that's how it went down. it's a night and day difference so if it doesn't really change much then leave it at 2 in cause you have a different problem.

hope that helps, gl

Dave

ill have to see if i can get ahold of another coolant temp sensor to try it out.

my safc settings are correct, also the grounds are at least a cm apart on wire, i possibly have the safc wired up wrong? i thought the pink and orange wires were the ones for the airflow? i had the white and yellow hooked up before but i read in the safc manual it was the other two? anyways some clarification would be amazing. and also note that unplugging the maf sensor doesnt change the cars behavior at all.

[240sxrb25]

how much length between maf and turbo. my maf is currently RIGHT before the turbo and im fixing it tomrrow.

aem wideband pinned rich ALL the time becuase of this mistake i made.

the turbulance of turbo is cause mad MAF readings.

idk if you did the same or not....

let us know

[slider2828]

Well did the car run fine before? Stock FP is 43 PSI with the vacuum off....

[Destructodc74]

how much length between maf and turbo. my maf is currently RIGHT before the turbo and im fixing it tomrrow.

aem wideband pinned rich ALL the time becuase of this mistake i made.

the turbulance of turbo is cause mad MAF readings.

idk if you did the same or not....

let us know

my maf has at least a foot clearance before my turbo but my piping is aluminum from the turbo to the maf so could that be it? the car runs like the maf is unplugged though i cant rev it past 3.5k rpms
Well did the car run fine before? Stock FP is 43 PSI with the vacuum off....
i never saw the motor run before i dropped it in, but it has to be some sort of maf/fuel problem and i think it has something to do with the maf wiring... ill get on checking the fuel pressure but i doubt its that.

[Z U L8R]

your safc is wired wrong.

identify your maf signal wire, cut it and connect your safc like so

your safc's white wire goes to your maf side of the signal wire

your safc's yellow wire goes to your ecu side of the signal wire

Dave

[Destructodc74]

thats how it was wired before and it still made no difference. its as if my maf is unplugged and my ecu is in limp mode

[Z U L8R]

you may have a burnt maf circuit in your ecu, but you definitely use the white/yellow safc wires for a hotwire nissan mass air flow sensor.

if you've already tried another known good maf, it's wired correctly, and your safc is wired correctly, then the only other thing you can do is

1. test continuity on your maf signal and ecu ground wires, then make sure you have power and ground on the other 2 wires. if that checks out ok

2. try known good ecu.

best of luck,

Dave

[Destructodc74]

does anyone have knowledge of how to indentify what year a motor is from by the vin on the side of the motor? i found out my ecu is from 10/93-2/95 and thats zenki.... and my motor has the fins on it meaning its kouki... so if anyoen can help me identify that i have the wrong ecu thatd be great. the code on my motor was

SR20 263365W

thanks in advance.

[Z U L8R]

man.....you can run an s14 sr with an s13 ecu and vice versa.... whether you have vvt or not doesn't change that it's an sr20 motor with basically all the same sensors and almost identical internals. as far as the maf's being different the safc calibrates that, so that's deduced as a culprit as well.

i have also seen safc's not send any signal back out to the ecu , even though it's saying everything's kosher with the voltages on the sensor check option.

first off, lets stop guessing and start testing. that's the only way you're gonna fix this without throwing a bunch of random parts on here and stumbling across the problem eventually.

make sure you have continuity on all your stuff. if you wanted to throw a new coolant temp sensor on there just to deduce that, it's cheap and do that. moving on.

do you have the factory maf? you can try without the safc....that would deduce whether the safc is bad and your wiring has a short. if you wire back in the stock maf, put it on and it still runs this way, then we can start testing other things.

i'm trying to give you tips and ways to test to isolate your exact problem without you spending any money aside from a coolant temp sensor. everything else is just not being lazy and testing this stuff.

if you ask for help, and we help by suggesting you test relevant things pertaining to your issues, and you don't do any of these tests....who's dropping the ball?

if we're leading you to water but you refuse to take a drink? how can we fix your thirst problem? lol

if our advice is outlandish , foolish, and has nothing relevant to do with your issues..then yeah...don't waste your time...but if it's good advice...don't waste ours...

best of luck,

Dave

[Destructodc74]

about what you said, no you cant, my friend cannot even run his blacktop sr with a redtop harness. the pins on some of the clips line up differently or something. so im pretty sure you cant run motors without having at least the vital parts the right one. so im not so sure you could run it smoothly with the wrong ecu...

[Z U L8R]

http://i214.photobucket.com/albums/cc313/Z_U_L8R/seans14srs13ecu.png (http://s214.photobucket.com/albums/cc313/Z_U_L8R/?action=view&current=seans14srs13ecu.png)

here's a stock s14 sr with a z32 maf, running off of a s13 ecu with an safc making almost 300hp on the stock s14 t28 @ 15psi lol

it can be done and it was done 2 years ago! i tuned the thing and here's the dyno sheet.

i didn't say it was all plug and play, but it can be done.....pretty easily. anyways that's not the point.

the point is i said the ecu's don't matter because you have an safc and since you won't do any continuity tests, you're assuming your wiring is correct. this was in response to you saying you have the fins in your head (so you have a blacktop s13 sr20det head) and you think you're running an older red top s13 ecu....therefore thinking that this may be the reason you're running super rich.

you think it's because the ecu is from a different year s13 sr20det. i would love to see the differences in the ecu pinouts of a red top s13 sr20det ecu vs a black top s13 sr20det ecu....:D

i agree, the problem may be the ecu, but not because it's a different s13 sr20det ecu, but because the maf circuit is fried in the ecu because some jack ass didn't wire in the z32 maf correctly the first time, had it backwards and fried the maf circuit, but since you won't do any tests on what would tell you what the problem is, all we can do is argue about irrelevant details and you're still guessing and throwing parts on your car hoping and praying it fixes it.

makes no sense lol, good luck tho nonetheless, eventually you'll install the right part on it that fixes the problem...

you could just do some more tests and isolate the problem, but what do i know.

Dave

[army240]

What I like about mechanics, is that we can test almost everything before changing parts. Like what is the resistance of the coolant temp sensor? What is you maf voltage to the ECU? What is your TPS voltage to the ecu? If you don't know how to do the test, or use a multimeter, I made a write-up for this.

http://zilvia.net/f/tech-talk/311598-how-electrical-diagnosis.html

Also, like I said in one of my other post, if you ask for help, please, at least listen to us. If you don't want to listen to us, it's your right. But be aware that it's very frustrating for us, who knows our shit.

So in my opinion, got to a shop.

Frank

[Destructodc74]

What I like about mechanics, is that we can test almost everything before changing parts. Like what is the resistance of the coolant temp sensor? What is you maf voltage to the ECU? What is your TPS voltage to the ecu? If you don't know how to do the test, or use a multimeter, I made a write-up for this.

http://zilvia.net/f/tech-talk/311598-how-electrical-diagnosis.html

Also, like I said in one of my other post, if you ask for help, please, at least listen to us. If you don't want to listen to us, it's your right. But be aware that it's very frustrating for us, who knows our shit.

So in my opinion, got to a shop.

Frank


first off, its a s14 sr and i believe im running a zenki ecu in place of the kouki one. not s13 sr if you had read. and i ordered a new coolant temp sensor because i need an s13 one anyways so my gauge will read correctly. my maf reads about 12 volts where it should and relays 4.9 volts to the ecu when the key is on. i havent tested the tps sensor yet but i will soon.

[army240]

first off, its a s14 sr and i believe im running a zenki ecu in place of the kouki one. not s13 sr if you had read. and i ordered a new coolant temp sensor because i need an s13 one anyways so my gauge will read correctly. my maf reads about 12 volts where it should and relays 4.9 volts to the ecu when the key is on. i havent tested the tps sensor yet but i will soon.

Where in my post it says that you have an S13sr?!? Anyway, FYI, there is two coolant temp, one for the gauge(1 wire) and one for the ECU(2wire). According to the FSM, MAF voltage should be 0.8 to 1.5V at idle, and 1.4 to 2V at 3000 RPM.

But yeah, what do I know...

Frank

[Z U L8R]

5 volts going back to the ecu for your maf signal is the problem. that's like the voltage for wide open throttle maxed out pegged out getting 100% air flow, no wonder the ecu is compensating by dumping fuel, it thinks you're flowing a crap load of air

yeah the last two posts i forgot which sr you have but the points i was making are still the same.

anyways.

at idle, get your safc into ETC. then go under SENSOR CHECK, what's your in and out maf voltage at 2 in 5 with the white/yellow wires wired in. what voltage does it say to you?

and Frank's correct about the sensors, there's a coolant temp sending unit (1 wire for guage) and a coolant temp sensor (ecu 2 wire). the one for your ecu can go bad and usually when they do they tell the ecu it's -40 degrees outside so the ecu dumps fuel.

anyways, i'm not mad at you, i'd like you to fix your car, and let everyone know what the problem ended up being that way it helps someone else who has a similar symptom.

i'm glad you're testing voltage measurements, ~5 volts at idle seems high to me lol

Dave

[Destructodc74]

Where in my post it says that you have an S13sr?!? Anyway, FYI, there is two coolant temp, one for the gauge(1 wire) and one for the ECU(2wire). According to the FSM, MAF voltage should be 0.8 to 1.5V at idle, and 1.4 to 2V at 3000 RPM.

But yeah, what do I know...

Frank

sorry i was referring to z u l8r with the s13 sr thing.

5 volts going back to the ecu for your maf signal is the problem. that's like the voltage for wide open throttle maxed out pegged out getting 100% air flow, no wonder the ecu is compensating by dumping fuel, it thinks you're flowing a crap load of air

yeah the last two posts i forgot which sr you have but the points i was making are still the same.

anyways.

at idle, get your safc into ETC. then go under SENSOR CHECK, what's your in and out maf voltage at 2 in 5 with the white/yellow wires wired in. what voltage does it say to you?

and Frank's correct about the sensors, there's a coolant temp sending unit (1 wire for guage) and a coolant temp sensor (ecu 2 wire). the one for your ecu can go bad and usually when they do they tell the ecu it's -40 degrees outside so the ecu dumps fuel.

anyways, i'm not mad at you, i'd like you to fix your car, and let everyone know what the problem ended up being that way it helps someone else who has a similar symptom.

i'm glad you're testing voltage measurements, ~5 volts at idle seems high to me lol

Dave

i figured 4.9 sounded high, but that wasn't at idle that was with the key on accessories. im going to test some more today so ill update with some numbers. yeah sorry if i sounded impatient or something im pretty frustrated at this point..

but anyways for the maf plug i had the key on accessories and it read this

- - - - - -
1 2 3 4 5 6

1- not used
2- 12 volts read at about ~11.1 with the car not actually running
3- ground. sufficient enough to get the 11.1 volts
4- ground. also sufficient
5- it read 4.9 volts with the key on accessories... this sounds completely wrong as you said, not to mention it wasnt even plugged into the maf so where was the voltage coming from? it should be relayed from the maf to the ecu correct?
6- not used.

but im pretty sure thats the order off the top of my head viewing from the harness side. i have a diagram so it should be wired up correctly.. im going out to rewire the safc now and to see if i cant get some more readings and a maf voltage off the safc while the car is running and etc. thanks guys for the continuous help.

[Z U L8R]

sounds good,

double check your maf wiring to my first post and if it's not wired that way, plz wire it that way and do the white/yellow safc wires how i explained too.

thx & gl,

Dave

[army240]

Check what Dave told you, if it don't work, tell us what's the voltage at : maf pin 5, right before SAFC, right after SAFC, and directly at ECU?

Reading 1 & 2 should be the same, reading 3 & 4 should be the same.

Tell us that!

Frank

[Destructodc74]

the car was idling at about ~ 2k rpms or so and the maf relayed 1.6 volts at the maf plug. and also the same on the safc for the in 1 reading. so thats right around where army240 said it should be. except the voltage from the safc to the ecu was 5.1 or something crazy, im assuming thats where my problem is then? if its not freezing tommorrow im going to wire up the sr maf and just unplug the safc and see what my results are. or do i need to wire back together the maf signal wire to have the safc actually unhooked?

[army240]

Good, you've narrowed down the problem!

Yes if you but back the SR maf, it would be better to run the maf signal directly into the ECU(not via the SAFC)

I'm not the SAFC Expert, but make sure all the setting in the SAFC are good, and your MAF signal is connected to pin 27... White Wire to the MAF, Yellow Wire to the ECU(As Dave said it earlier). I would double check that before trying the other MAF.

Is the SAFC new? Maybe it's just not good...

Frank

[Z U L8R]

hotwire, 2 in 5 out

[Destructodc74]

Good, you've narrowed down the problem!

Yes if you but back the SR maf, it would be better to run the maf signal directly into the ECU(not via the SAFC)

I'm not the SAFC Expert, but make sure all the setting in the SAFC are good, and your MAF signal is connected to pin 27... White Wire to the MAF, Yellow Wire to the ECU(As Dave said it earlier). I would double check that before trying the other MAF.

Is the SAFC new? Maybe it's just not good...

Frank

the safc is wired correctly now, but i think im going to try to wire the maf signal wire straight to the ecu like you said and put the stock maf on. possible even just unplug the safc altogether. that shouldnt create a break in the circuit right? but even though,

hotwire, 2 in 5 out
yeah thats what it was set at. maybe some other settings throughout the safc are set up wrong... im not great with it but ive read most of the manual and did the basics that it describes for setting it up for my car.

[bradyd15]

hey i was gonna ask you how to wire a e60 maf with a sr20det. ive got a apexi neo as well.