Still running LEAN at idle...

[rn240sx]

Ok, I removed the MSD box, but the stock distributor back on and put my 6 heat range plugs back in, the motor idle's SMOOTH and have no hesitation at all... Boost comes on quick and no more throttle problems...

But here is the other deal. Im still running 19.9 on the wideband at idle. I have to tune the afc to +50 to get the a/f at 14-15 for it to run smooth..

Is this an indication that the narrowband output from the wideband has gone bad..??

I can swap out the wideband for the regular O2 sensor, but thats like an hour job for a 30 second swap..

b4 i do this i wana be sure that the 02 sensor is the main culprit for this lean idle mixture...

What else can cause this lean mixture at idle..??

[:: orion ::]

O2 sensor is ignored at idle and WOT...

Check your fuel pressure...(?)

- Brian

[WDRacing]

Huh, I thought it was WOT only. Learn somthin everyday.

[s13sr20chris]

where are you reading your a/f?

if that really is your a/f the car should idle bad.

[rn240sx]

where are you reading your a/f?

if that really is your a/f the car should idle bad.

Where, ahh from my wideband O2 which is on the downpipe...

Yes it DOES idle bad as i stated b4, UNLESS i tune the afc +50 % so that i can get it to 14-15... then it idle's perfect.

But there shouldnt be any reason to mess with the afc to get it at that a/f ratio during idle... Ive never had this problem b4..

[uncle_louie83]

at idle your a/f ratio will bounce back and fourth between lean and rich....all my turbo cars have done this and all my all motor cars have too.

lewis

[rn240sx]

at idle your a/f ratio will bounce back and fourth between lean and rich....all my turbo cars have done this and all my all motor cars have too.

lewis

Yeah thats on a standard narrowband a/f gauge.. A Wideband does not do that. Mine since day one has been solid at 14.6 at idle and has gotten worse over time and i cant figure out why. Even with tunning the afc to +50%... its not helping anymore. Now its gotten to the point where i sound like i have lumpy cams and the car will barely idle..!!

[S14tat]

i remember anthony's wideband 02 sensor went bad like last year. it was driving him nuts casue he couldn't figure out why he running 12-13:1 afr no matter how much he tuned it at WOT.

he said the main symptoms for a bad wideband 02 sensor is that it would not read the extremes on both ends. that means that at first it wouldn't go to AIR or RICH. then it wouldn't go to 19:1 or 10:1 then 18:1 or 11:1 and so on. the range it would read gradually gets smaller and smaller

i think the reason why his failed was because he runs alot of race gas and race gas leaves that white film in your tail pipe. do you run alot of race gas?

[rn240sx]

i think the reason why his failed was because he runs alot of race gas and race gas leaves that white film in your tail pipe. do you run alot of race gas?

I run 100 octane (cam 2) un-leaded gas all the time cause 93 pump limits me to ~14 psi. This car is not a dailr driver, its my weekend street racer so i dont even bother running pump anymore. Since im always pushing over 14 psi when im racing...

[S14tat]

does your wideband show extremes on either end of hte spectrum though? like dead rich or dead lean?

[emperor_lunchbox]

off topic rn240sxwhere are you in orlando?

[rn240sx]

does your wideband show extremes on either end of hte spectrum though? like dead rich or dead lean?

Well, when i let the pedal go (closing the throttle plate to decelerate) the wideband goes to LEAN 19.9 and stays there for a while until the car comes to a stop, then it will jump back to mid 14's... This i think is new and i dont recall it ever dropping to dead lean like that b4... Or maybe i just didnt pay too much attention to it when i come off throttle... so it may be normal..

Also when i 1st hit the gas pedal, it will go to pig rich for a split second then go to mid 14's as normal if im in vacuum mode..

Hope that was what u were looking for...

off topic rn240sxwhere are you in orlando?

Im on the border of orlando and kissimmee. Hunters creek community. John Young and Deerfield.

[S14tat]

hmmm then it seems like your wideband is working fine. but whats odd to me is that when your letting off, it read lean. haha even though mine is recirculated, it still reads RICH when i let off then it stablizes it self. thats why whenever i go to the dyno, when they let off, theres a big puff of black smoke.

anyone else can chime in here and see what the car is suppose to do when you let off on boost? or just letting off the throttle in general?

[Structure240sx]

my jwt ecu is the same way at idle. i have +50% on my safc for idle

[S14tat]

did it go up? i remembered you having to go like +27 before or something like that becsaue i'm at +25 on idle. or did i just remember it wrong?

[DammitBobby]

Well, when i let the pedal go (closing the throttle plate to decelerate) the wideband goes to LEAN 19.9 and stays there for a while until the car comes to a stop

I have JWT ECU 72lbs program, SAFCII and mine will go 21 when I let off the pedal and will stay there until I reach stop point. I turned my DEC setting to 0 because the bov is recirculated. I know I have to richen mine as well at idle because it will read around 18:1 and wont idle. I think I have mine set to around +30% at 1k. When I had a open atmosphere BOV I had to turn mine all the way up to +50%.

S14tatI don`t have any black smoke when I let off the pedal.

[rn240sx]

Well, when i let the pedal go (closing the throttle plate to decelerate) the wideband goes to LEAN 19.9 and stays there for a while until the car comes to a stop

I have JWT ECU 72lbs program, SAFCII and mine will go 21 when I let off the pedal and will stay there until I reach stop point. I turned my DEC setting to 0 because the bov is recirculated. I know I have to richen mine as well at idle because it will read around 18:1 and wont idle. I think I have mine set to around +30% at 1k. When I had a open atmosphere BOV I had to turn mine all the way up to +50%.

S14tat

I don`t have any black smoke when I let off the pedal.

I guess im NOT the only person with this IDENTICAL MIRROR image problem..!!! Thats 3 of us with this problem and all of us are running the jwt ecu with over 370cc inj program. I didnt have this problem with the 370cc program..

Well i guess its normal and there is nothing physically bad... Just have to either deal with it or dump jwt.

[S14tat]

yeah when i first had the JWT, it freaked me out. i was like wtf is going on, why won't the thing idle. i had it sent back twice for inspection. then i'm just like F.. that i wanna run more then 10 psi so i just band aided with my safc. as it turns out like a few weeks later, anthony got his JWT program back and he had to do the same thing.

and dammnitbobby, i see mine is the one thats alittle weird. hmmmm we'll as long as it doesn't stall and i'm still getting 21+ mpg i'm fine. but thats definitly something i should look into when i'm really bored.

[DammitBobby]

I have a snap shot of my data log in this threadhttp://forums.nicoclub.com/zerothread?id=161172 I tuned it this weekend.

[rn240sx]

The bottom line is we should NOT have to use an afc to fine tune the a/f curve to stabalize the idle...That is a problem with jim wolf's tunning and it needs to be fixed. Their 370cc program is flawless at idle, why can the 550,615 and 740 programs be the same. I can understand having problems with something like 1000cc+ sized injectors especially at providing a smooth idle, but c'mon... Again, we should NOT have to use an afc to tune this...

[S14tat]

went i sent the ecu back to them, they seem to run it on some kind of simulator, not on a actual car, and they're telling me that its the right program and that its works flawlessly on their computer. i mean how else can i argue with that right?

well thats were scott enthalpy comes in. when nissanfanatic got his tune, it started right up and almost everything was right on the money.

[DammitBobby]

Yep I am with you on that one idle should be the same for all programs no matter what turbo you are running. To be consistantly off that much they need to make a change to there simulator. Answer is JWT and SAFCII or Scott Enthalpy. If I had to do it again I would go with Scott I have yet to hear anything bad about his tuning abilities.

[rn240sx]

went i sent the ecu back to them, they seem to run it on some kind of simulator, not on a actual car, and they're telling me that its the right program and that its works flawlessly on their computer. i mean how else can i argue with that right?

Flawlessly on a computer vs testing it on an actual motor are 2 totally different things. Thats their answer to "they cant fix it".

Im gonna switch to enthalpy's tune..!! There is no reason why we should have to run an afc to get smooth idle.. thats rediculous.

[klattr1]

O2 sensor is ignored at idle and WOT...

Check your fuel pressure...(?)

- Brian

i thought it was only ignored at WOT (open loop) and would operate in closed loop at idle and partial throttle situations.

at idle when warmed up, the 02 voltage oscillates (rich to lean)...whenever i had a bad 02 or wiring was funky, i would produce a low voltage at idle (around .33 volts steady...not oscillating like it should) and my car would in turn run rich (due to wideband readings and black sut on my rear bumper hehe).

now whats causing Robert's (rn240sx) situation...im not sure...my old cobra mafs/72lb JWT program idled very nice (around 14:1-15:1)...i imagine that if his 02 was bad and was sending a high voltage signal to the ecu, that his car could actually run leaner in result (causing some rough idling)...

i never liked the idea of using a wideband to simulate the narrowband voltage...thats why i always kept mine separate (two bungs, two different sensors)...

dont turn this into a JWT bash...even Enthalpy ecu's have had some problems...not every tune will be perfect.

BTW...both Enthalpy and JWT offer retunes...its not the end of the world.

[Structure240sx]

im very happy with my results with my jwt