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View Full Version : My SR is hitting fuel cut/2 stepping at 2-2500 rpm but Idles Fine????


VegasDrifterS13
01-16-2014, 10:28 AM
OK. So I replaced my hot pipe and put on some new couplings and Tbolt clamps in necessary places. I Also Sold my SAFC-II because My ECU is tuned by Redline and all the Values were at 0% and my car doesn't lean out anywhere so it was unnecessary. I only disconnected the plug. the harness is still piggybacked onto my harness. The Vacuum Ports Are All T'd/Connected together (got it this way, ran fine before). After EVERYTHING was Back Together I started It with the MAFS unplugged. Ran Like Shit Just like it does now. I killed it and searched. Found MAF unplugged and plugged it In. Started it up and NO DIFFERENCE.

THINGS I HAVE TRIED:

1. All my Couplings Are TIGHT.
2. MAFS SEEMS TO NOT BE WORKING, Runs the Same REGARDLESS of it being Plugged In or Not.
3. My Fuel Pressure Is Fine, No ISSUES.
4. Idles Fine so My Coils And plugs are working...

MY QUESTIONS

1. IS my ECU in a LIMP mode because I started it without the MAFS Plugged In?

2. FROM MY UNDERSTANDING, TO GET THE ECU TO FLASH ME CODES, I TURN THE LITTLE SCREW ALL THE WAY RIGHT THEN ALL THE WAY LEFT???

3. HOW DO I TEST MY MAFS ?

di-devol
01-16-2014, 10:34 AM
If you had safc installed but did not removed the harness, your maf wire is cut. Removed all wiring from the safc. The safc intercepts the maf wire then sends the modified signal back to the ecu. No safc, no connection.

And a side note, nissan ecu's do not have fuel cut -_-

dorkidori_s13
01-16-2014, 10:52 AM
car is in safe mode. ECU isnt reading the MAF. do like di-devol said, remove all SAFC wiring and put back to factory spec.

side note, i would HIGHLY recommend you buy a Nissan data-link cable for your car and get a copy of either NISTune or ECU-Talk. This will make diagnosing your motor issues about 1000000x easier! being able to see all your read outs/ecu faults (including seeing your MAF voltage to check if faulty) on a laptop takes any and all guess work out of things. no more throwing parts at the car!

rwtf
01-16-2014, 11:11 AM
facepalm....obvisouly a fucking MAF issue.... jesus....

di-devol
01-16-2014, 11:25 AM
facepalm....obvisouly a fucking MAF issue.... jesus....

Obviously, but to him he didn't seem to know that the maf wire is intercepted by the safc. Now he learned something new!

You don't have to be a dick, especially after the question was answered.

dorkidori_s13
01-16-2014, 11:34 AM
facepalm....obvisouly a fucking MAF issue.... jesus....

Perhaps you should chill out with the insulting tone and learn a little patience with people who are actually asking for help after exhausting their own knowledge!

VegasDrifterS13
01-16-2014, 01:56 PM
Thanks Di-Devol, and DorkiDori. I have Had A Nistune Daughterboard Before and that was my Best Running SR. Ill google where to buy one, I have the E5 ECU now.

I will disconnect all the SAFC-II subharness & update. thanks Again.

VegasDrifterS13
01-16-2014, 02:06 PM
facepalm....obvisouly a fucking MAF issue.... jesus....

Your rudeness is quite unnecessary. OBVIOUSLY I knew it was related, I SAID IT WASNT WORKING IN MY OP. FACEPALM back at ya for Your inability to read. Ive Never Had a Piggyback controller before, Now I learned how they alter signal, How they are connected, WHY I shouldn't USE one - lol, and how to Diagnose issues in the future and Help others having similar issues.

please be Constructive with your criticism. Destructive criticism just makes you look bad and Doesn't put Either persons foot forward EVER.

Kingtal0n
01-16-2014, 02:09 PM
Yeah, the minute someone says anything about that magic number "2500rpm" you can usually relate it the maf sensor.

And it is a fuel cut. Nissan ECU stops injecting fuel to limit the RPM.

ultimateirving
01-16-2014, 03:56 PM
e5 might not have a diagnostic light too.. so get that consult cable wired in

RalliartRsX
01-16-2014, 04:34 PM
Please the excuse the worthless human being "rwtf". As you progress through Zilvia, you will realize there are ALOT of assholes like him on Zilvia. Just ignore them. I commend you on your response and taking the high road :)

Anyways, typically I don't help out "newbs" but you seem like a cool guy

1) Look up and download the AFC (Neo or whichever one you had before you sold it) PDF manual. This manual will have the wiring diagram, associated wiring and their use, etc
: Page 6 of the AFC NEO manual here may help: AFC NEO Manual (http://www.apexi-usa.com/manuals/electronics/neo_diagram.pdf)

2) For the S13 based ECUs (E5, #62, etc), the correct pin number is listed below and should be one of several white wires. Use the below and the manual above to to trace the wire for the MAF signal (it will either be tapped, spliced or whatever the previous owner did) and reconnect the wire. This should fix you right up!
http://i9.photobucket.com/albums/a90/kingtal0n/62toJ4.jpg

Good luck!

Kingtal0n
01-16-2014, 05:01 PM
Please the excuse the worthless human being "rwtf". As you progress through Zilvia, you will realize there are ALOT of assholes like him on Zilvia. Just ignore them. I commend you on your response and taking the high road :)

Anyways, typically I don't help out "newbs" but you seem like a cool guy

1) Look up and download the AFC (Neo or whichever one you had before you sold it) PDF manual. This manual will have the wiring diagram, associated wiring and their use, etc
: Page 6 of the AFC NEO manual here may help: AFC NEO Manual (http://www.apexi-usa.com/manuals/electronics/neo_diagram.pdf)

2) For the S13 based ECUs (E5, #62, etc), the correct pin number is listed below and should be one of several white wires. Use the below and the manual above to to trace the wire for the MAF signal (it will either be tapped, spliced or whatever the previous owner did) and reconnect the wire. This should fix you right up!
http://i9.photobucket.com/albums/a90/kingtal0n/62toJ4.jpg

Good luck!

I made this diagram in photoshop years ago after needing to use the J4 on a 62 harness. Sight for sore eyes, let me tell you the days of S13 sr's is gone for me... rip

VegasDrifterS13
01-16-2014, 06:46 PM
Thanks to you as well KingTalon / ralliartrsx. I removed it all and soldered the MAF lead back together. !!!!!!!RUNS GREAT!!!!!!

Thanks Again Guys. Saved Me Tons of time.

di-devol
01-16-2014, 08:01 PM
Right on, good work.