sr20det running lean? positive feedback would be appreciated

[hbg240sxtuner]

ok guys, here's the run down, im a nissan tech so i deal with usdm stuff on a daily basis, but this one has me stumped because its only my second sr build.

i have a 91 hatch with a s13 redtop and the following modifications:

-legit greddy mani
-fmic
-mr ex. mani and elbow
-s15 t28
-stock inj.
-stock tune
-z32 fuel filter
-walboro 255 fuel pump
-greddy bov(located on hot pipe)
-s13 maf(located on cold pipe)>to allow for atmospheric blow off without running rich
-stock boost

-the issue is that my air/fuel ratio's are showing about 118%-130% when hooked up to the consult II factory scan tool. i have a feeling that the injectors aren't large enough for the volume of air put out by the bigger turbo, but i know for sure that there are no air leaks after the maf. i also have a feeling that the stock injectors might not be putting enough fuel into the mix. i was told by import intelligence that i would be ok to run the car with the afore metioned modifications with no issues and not have to get it tuned untill i upped the boost/inj size/changed maf/etc...

so if anyone has any useful information or has run into similar issues, let me know what you think/ found.

thanks

[kognition]

It sounds like your injectors are leaning out. Are you also running stock cams?

ok guys, here's the run down, im a nissan tech so i deal with usdm stuff on a daily basis, but this one has me stumped because its only my second sr build.

i have a 91 hatch with a s13 redtop and the following modifications:

-legit greddy mani
-fmic
-mr ex. mani and elbow
-s15 t28
-stock inj.
-stock tune
-z32 fuel filter
-walboro 255 fuel pump
-greddy bov(located on hot pipe)
-s13 maf(located on cold pipe)>to allow for atmospheric blow off without running rich
-stock boost

-the issue is that my air/fuel ratio's are showing about 118%-130% when hooked up to the consult II factory scan tool. i have a feeling that the injectors aren't large enough for the volume of air put out by the bigger turbo, but i know for sure that there are no air leaks after the maf. i also have a feeling that the stock injectors might not be putting enough fuel into the mix. i was told by import intelligence that i would be ok to run the car with the afore metioned modifications with no issues and not have to get it tuned untill i upped the boost/inj size/changed maf/etc...

so if anyone has any useful information or has run into similar issues, let me know what you think/ found.

thanks

[hbg240sxtuner]

also incase it helps

nissan factory closed loop air/fuel operation

80%-90%= running extremly rich

91%-99%=running slightly rich so the computer is leaning up the fuel mixture

100%=ideal, not adding fuel or taking any away(14.7)

101%-109%=running slightly lean so the computer is trying to richen up the fuel mixture

110%-120%=running extemely lean

normal operation should bounce around anywhere from 91%-109% and not be detrimental to engine operation

so as you can see i am way out of normal operating range.

sorry again, but i am mainly school in the factory nissan stuff for the usdm.

[hbg240sxtuner]

yes sir stock, stock engine except for the bolts ons

i just wanna make sure there isn't something dumb that i'm over looking before i get like 550's and have to get the ecu tuned

[slider2828]

You are 10000% correct. S15's had 440cc injectors. 370cc for redtops.

[blackej7]

http://img27.imageshack.us/img27/2362/103dutycycle.jpg

stock sr, stock tubo/injectors/ecu, top of 3rd gear.

id imagine with a bigger turbo, your injector duty cycle is even higher than 103%. my a/fs were safe though, around 11 i think.

[hbg240sxtuner]

ok, so here's what i found. i have a buddy with an s13, so i tried changing out parts from his car. known good parts that is.

-swapped maf sensors.. still ran lean
-swapped his fuel rail with nismo 555cc injectors, as well as tuned ecu.. still ran lean

so i was just curious <since buddy has basiclly the same setup as mine, but with the injectors and tuned ecu> if my mounting of the maf on the cold pipe has anything to do with my issue, because that is the only other difference between our two cars as they sit in my drive way.

let me know if anyone else has run into this issue (running lean) when mounting the maf on the cold pipe to accomidate atmospheric blow off without adverse driveability issues

Bump for some advise!

[clark]

ok, so here's what i found. i have a buddy with an s13, so i tried changing out parts from his car. known good parts that is.

-swapped maf sensors.. still ran lean
-swapped his fuel rail with nismo 555cc injectors, as well as tuned ecu.. still ran lean

so i was just curious <since buddy has basiclly the same setup as mine, but with the injectors and tuned ecu> if my mounting of the maf on the cold pipe has anything to do with my issue, because that is the only other difference between our two cars as they sit in my drive way.

let me know if anyone else has run into this issue (running lean) when mounting the maf on the cold pipe to accomidate atmospheric blow off without adverse driveability issues

Bump for some advise!

your placement of the MAF right before the throttle body puts you at risk of getting oil/gunk/shit on the MAF element so maybe hte MAF isn't reading properly...

did you happen to test with both HIS MAF and HIS fuel rail with the 550s??

how do you know you are running stock boost? do you have a boost controller and boost gauge?

what is your fuel pressure?

make sure your TPS is within spec.

[cotbu]

Get a wideband...! You are still guessing, just like the ecu with the narrowband. You can probably get away with tuning feedback on an N/A engine, but it's much easier with a real afr sensor.

[hbg240sxtuner]

in responce to clark: my maf is about 12 inches in front of the throttle body, but its right after a bend, and from what i know,<may be enough> turbulant air isn't easily read by a maf of that design. all my readings are within spec,
so i'm just gonna move the maf to the intake and i'll let you guys know what i find. and get a wide band on order

thanks for the suggestions, they are greatly appreciated

[0wn3r]

well i would recommend almost anyone w/ an SR to recirc..but at this point sounds like it may hurt you.

i have an S14 motor w/ S15 turbo and still have the 370cc injectors in there and run rich. are you sure 370cc injectors are the smallest in an S13 motor? maybe make sure they are flowing right as well

it's the right MAF right? just asking cuz i had ONE character off and mine ran super rich.

[hbg240sxtuner]

ok guys, so i moved my maf sensor back to by the air filter, and now the thing runs like a top. went out and drove it around for a little to break in the new turbo and clutch.

so i guess moral of the story is:

-don't run your maf sensor on the cold pipe because <at least> the stock maf can not acuratly monitor the air and will make it run lean due to its inabilty to monitor the turbulant air from the turbo<boost pressure>

so thank you all for your assistance and information, still have a speedo/odometer/tripometer issue, but shouldn't be difficult to figure out.

[reccakun08]

glad you figured it out. what you probably got confused with is that often people suggest relocating your bov to the cold pipe and not your maf.