Air-Fuel Guage readings....
 

guys, i'm about to rip my hair out, please prevent me from being called "baldie" and help!...

basically i called my local RX7 shop and they are saying the max i can run with stock injectors is 12psi, ok ok thats fine but he went on to tell me that on my air fuel guage it should read MAX rich, all the way too the right at WOT.... mine doesent, it reads the end of stoich or the begining of rich, is this ok?...

he said i could be leaning out, but i severely doubt i am, i boost at 10psi in 1st and 2nd, spike for a hal second in 3rd too 12psi and 4th-5th spikes at 15psi and slowly comes down, needless to say i dont go WOT or anywhere near it in 4th and 5th....

what you guys think, my mods are as followed....


Mods:

- 3" Racing Beat Turbo-Back Exhaust
- Blitz SS BOV
- Coilovers ( Tein rear, Ground Control front )
- Centerforce Dual-Friction clutch
- HKS PFC F-Con
- HKS GCC
- HKS Turbo-Timer
- FCD
- FD Flywheel
- JDM Brake Booster
- Stainless-Steel Braded Brake Lines
- SRP Boost controller
- Autometer boost and A/F guages
- MazdaSpeed steering wheel
- MazdaSpeed racing pedels
- Manaray 6spoke 16" rims
- Ractive tornado cone filter
- Yokohama AVS ES100 Z-Rated rubber
- Greddy ProfecB SpecII Boost controller
- Walbro 255lph Fuel Pump
- MSD 8.5cm Race-Wires
- Strut-Tower Bar

i will have greddy front mount in 2weeks aswell as a profecB specII, only thing i dont have is injectors.... yet....

all input is greatly appreciated!...

oh, and whats the max PSI i can run with everything but the injectors...?


I want to know if the way my car's running right now is infact leaning out....

thanx!...

Too much boost, not enough fuel = lean!

What really did you want us to say?

i want to know if what i'm running right now is infact leaning out my car....

yes i know too much boost will make it lean out, but with my setup and mods, does it sound right that the guage should be reading all the way burried into the RICH side...?

Very possibly, have you tried adding more fuel with the PFC at higher rpm's/higher load?

no not really, the air/fuel guage doesent move or change no matter what the revvs are....

right now it runs, like i said, at the end of stoich and sometimes the begining of rich....

really, dont risk it on that peice of shit narrowband gauge, get/borrow a wideband to be sure.

i'm just wondering if the readings i'm getting front my narrowband is legit, i mean it's on the rich side and no where near the lean side, isnt that enough?... it doesent go any lower then 3/4 of the stoich.... the car runs very rich 24/7.... i'm not understanding how i could be leaning out, i always hear "if your running more then 13psi+ you could be leaning out" but i'm just at 10psi....

i'm running 94octane aswell and my car runs very, very rich 24/7 but i think i already mentioned that.... shoots fire too....

you need a wideband to be sure.

*sigh*....

now i'm pretty worried, all seams normal and i thought i would be cautious not to pin it in 4th and 5th to get that 15psi spike and all....

frig.... mabe i can get a boost controller and keep the boost at 10psi for now to be on the safe side....

You might have a slight ground differential between the AFR gauge and the O2 sensor.
I would recommend tying in the O2 sensor with the gauge ground.
Easiest way is to crimp a male spade or male flat crimp onto a piece of wire, use a hose clamp to clamp the fitting onto the O2 sensor, and then run this wire with the ground on the gauge.
This eliminates any ground differential between the two and will give you a more accurate reading.

Single wire O2 sensors are notorious for this, as it has to ground through the exhaust system of the engine!


-Ted

You're slackin Ted, you didn't bitch about the fact that a boost controller doesn't lower boost!

Even with a boost controller you're going to get those spikes, the only way to combat is to port the wastegate.

Godfunit, it's 2AM here, and I'm working my second 8 hour shift after getting off the first one. :P


Of course, you are correct!


-Ted

the new turbo with 35mm ported wastegate will be installed in about a week, mabe 2....

sorry, forgot to mention that....

What was said about the grounding of the 02 sensor is very true. I used to monitor the afr using a digital meter. I could see there was something not quite right. So I installed a ground wire on the body of the 02 sensor using a water hose clamp. Grounded the other end to the engine. The readings improved considerably.

I got that idea off this site. I was a doubting Thomas. After all the exaust is metal, the trubo gasket is metal, everything is metal. CAn't be true. WAs true. Do it.

if I were you I would just go with 720cc secondaries or something. they fit into the stock rails. and you need to get a wideband :p:

i'm not tuning the car or anything, i'm going to run minimal boost, 10psi untill next year when i drop the 860cc's in the secondary's and tune the SAFC-II that i will be installed to give enough fuel for the BNR Stage 3....

in the mean time i think it's alright.... i get somewhat a dithered display on my AF guage too, it lightly lights up a few boxes around the solid colored one....

your not getting it, the stock o2 doesn't read the real air/fuel ratio....you could be runing lean and it won't even show it as lean

your better off using a EGT gauge

i guess i'm not getting it then....

fine i'll change the O2 sensor then....

mabe i'm completely not understanding how my car could be running lean though i spit fire like a mofo and have the presence of gas 24/7....

oh, thought i would also mention, when i get off the gas and all the AF guage goes far lean, no lights are lit so basically it disapears to the far left, when i'm at different throttle positions it will read differently, 20% throttle it'll read near lean, 50% throttle will be middle of stoich, and full throttle will be end of stoich or begining of rich....

If it wasn't for that "piece of shit" he would have no idea there may be a problem. He never said anything about tuning so there's no need to go out and blow money on a wideband. People seem to have a hard time grasping the fact that an A/F gauge is a very useful warning and diagnostic tool.

Archangels, the best way to confirm you mixtures is with a wideband A/F meter, and the cheapest and easiest way to do that is on a dyno. Stay out of that high boost too. That's just asking for trouble, partucularly with suspect mixtures. Get that new turbo on ASAP.

You guys needs to do your research before spouting this bullshit.
The narrow-band O2 sensor is VERY ACCURATE at stoic - 14.7:1.
To be claiming otherwise shows you're very ignorant of the facts.


-Ted

you guys are my hero's....

i never boost in 4th or 5th for now, i'm going to be getting 860cc injectors and my BNR installed aswell as the SAFC-II installed and tuned, till then i should be good with this, no more then 10psi in first 3gears, thanx alot for your guys' help!...

Just as a side...

You mention you're running a Walbro...

Can you confirm the Walbro is getting full voltage?
Did you rewire the fuel pump power side?

I only mention this, cause I recently found out my FC only sees *8.0* volts, and if the stupid two-stage voltage relay happens to switch over (which is NOT consistent), it barely registers *10.0* volts!

My EGT gauge was first to show there was something wrong. :(
I was only able to get a dedicated voltmeter to watch the fuel pump power levels.
This is scary SHIT! :(


-Ted