Wideband max LEAN, but blowing black smoke?

XpL0d3r

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B18B stock internals running 9psi on a T3/T4 .60 trim. Walbro 255lph fuel pump. Injector Dynamics 720cc injectors.

It's been cold lately. I mean COLD. High of 15 degrees or so all week, sometimes below zero at night. Anyways, got my car back from an oil change yesterday and drove it to work fine. On the way home, I noticed that the wideband gauge was stuck at 20 (max lean). This was at idle, on the gas, or off the gas just coasting. When I let off the gas driving, the gauge would sort of jump around, even hit 10 (max rich) for a few, but would jump right back up to 20 again.

Started her up this morning and the same thing -- wideband gauge is reading 20. Noticed a lot of smoke coming from my car, which happens when it's really cold -- but this time I noticed there were puffs of gray / black smoke as well, indicating fuel. Why would I be burning fuel if the gauge is saying I'm running lean? I revved the car once, got out to look at the smoke from my exhaust, and by the time I got back in my car (left the door open), it smelled like fuel in there.

I let the car warm up and the smoke pretty much went away, but the gauge was still reading 20. A couple of times it dropped down to 14.8 which is pretty much normal, but would shoot back up to 17-18 briefly and then back to 20... Calibrated the gauge -- same results.

Any thoughts? Things to check? Thanks guys.
 

2slo4u

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no exhaust leaks right?
has to be your sensor......or if you have an exhaust leak you could be going completely rich because the o2 sensor is reading only air "hence lean reading on your sensor", and the computer is compensating for the lean air by dumping fuel, therefore your running rich which could have fouled your wideband sensor.
 


XpL0d3r

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Yeah no exhaust leaks afaik. Although when I picked my car up from the shop it was parked off to the side of the shop (dirt spot) and I scraped my exhaust backing out... was OK on the way to work though -- started happening on the way home.

I didn't calibrate the sensor right either -- I did it with the sensor IN the exhaust lol. I probably should remove it and then calibrate.. It's freezing right now so maybe this week I'll get to it and update. I'm nervous / afraid to hit boost right now though.
 

b16lewis

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recalibrate your wideband
 


XpL0d3r

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Forgot to mention it's tuned open-loop.. the only o2 sensor in my car is the one for the wideband, lol.

Anyways -- she started rough a few minutes ago. Sat there and the idle fluctuated +- 500 rpm's or so. It stopped for a couple minutes, idled fine, and then did it again for another couple minutes... then idled fine again.

Didn't get a change to recalibrate the sensor yet, but it's supposed to be in the mid 50's mid-week so I'll hopefully get to it then!
 

mc360

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Like others said you could have fouled the wideband. Just curious what brand wideband are you using, I have a glowshift and its crap and I have herd the arm wideband isn't to good either
 

XpL0d3r

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Like others said you could have fouled the wideband. Just curious what brand wideband are you using, I have a glowshift and its crap and I have herd the arm wideband isn't to good either
I have glowshift. lol.

Car was fine this morning, other than the gauge reading 20. But I noticed something pretty strange -- when a passenger stomps there feet over there (not even that hard), but RPM's fluctuate. My gf even got my car to STALL by doing it. Pretty sure there's a wiring issue over there. The OBDII-OBDI wire harness was cheap so that will be the first thing that I check. On Wednesday. When there isn't ice and cold weather. lol.
 

obracer12

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the passenger issue = Loose ECU clip ( happened in my turbo B) My friends think their Neil Pert...

The rich condition in cold weather is an over compensation from the ECU, mine ( S300) does it all the time when the temperature drops between 10-20 degrees F. Can't get it to not do it. When it's that cold the air is saturated in Oxygen/Nitrogen, the ECU simply pins into the AFR even if you run an open loop or have a X-Bar MAP sensor.

Having said that you should at the most get little puffs of black, not Diesel soot.

To be sure check your oil and coolant for intermingling fluids , you could have a hairline in one cylinder head gasket causing a slight oil burn + rich cylinder.
 

mc360

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I have glowshift. lol.

Car was fine this morning, other than the gauge reading 20. But I noticed something pretty strange -- when a passenger stomps there feet over there (not even that hard), but RPM's fluctuate. My gf even got my car to STALL by doing it. Pretty sure there's a wiring issue over there. The OBDII-OBDI wire harness was cheap so that will be the first thing that I check. On Wednesday. When there isn't ice and cold weather. lol.
stupid auto correct ( i ment aem) anyways i would ditch the glowshift and get a innovate mtx-l or other model i have herd alot of good things about them. as soon as i get money i will be ditching my glowshift and getting the innovate wideband since i noticed that my wideband was off 2 points from my tuners dyno setup, his would read 14.0-1 and mine would read 12.0-1 .

i would ditch the cheap obd conversion harness and get a good one like boomslang or get one from xenocron.com which is where i got mine and have no problems
 

XpL0d3r

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the passenger issue = Loose ECU clip ( happened in my turbo B) My friends think their Neil Pert...

The rich condition in cold weather is an over compensation from the ECU, mine ( S300) does it all the time when the temperature drops between 10-20 degrees F. Can't get it to not do it. When it's that cold the air is saturated in Oxygen/Nitrogen, the ECU simply pins into the AFR even if you run an open loop or have a X-Bar MAP sensor.

Having said that you should at the most get little puffs of black, not Diesel soot.

To be sure check your oil and coolant for intermingling fluids , you could have a hairline in one cylinder head gasket causing a slight oil burn + rich cylinder.
Yeah. I figured the car would run a little rich, but previously it never did it when warming up. I'd be driving 30 minutes to work, and maybe 10 mins into the drive the AF gauge would just drop right to an 11 or 12 which is pretty rich. But the kicker.. when I took my foot OFF the gas, instead of shooting up to a 20 like it should, the gauge actually DROPS to a 10 (max rich), and I can feel the car acting goofy. There's no o2 sensors in the car either (open loop tuned), so I'm not sure why it would do that...

stupid auto correct ( i ment aem) anyways i would ditch the glowshift and get a innovate mtx-l or other model i have herd alot of good things about them. as soon as i get money i will be ditching my glowshift and getting the innovate wideband since i noticed that my wideband was off 2 points from my tuners dyno setup, his would read 14.0-1 and mine would read 12.0-1 .

i would ditch the cheap obd conversion harness and get a good one like boomslang or get one from xenocron.com which is where i got mine and have no problems
Yeah I got all good parts when I did my turbo build... minus the gauges :/ figures haha :smackself I think I fouled the sensor though.. going to test it either today or tomorrow afternoon hopefully.
 
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TokyoSkies

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I too suffered from fuel curvature and temperature fluctuations. I used to park my turbo integra outside. I'd get up at like 5:30 for work, warm the car up for about ten minutes, and I'd notice that my idle would be a bit.. off.. I never got black smoke (little puffs here and there, as to be expected), but the car ran strange until it was warm enough outside for proper combustion. I didn't know what the hell was going on until I consulted our local tuner. I guess this is a common occurrence for cars that aren't boosted factory.
 

XpL0d3r

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I too suffered from fuel curvature and temperature fluctuations. I used to park my turbo integra outside. I'd get up at like 5:30 for work, warm the car up for about ten minutes, and I'd notice that my idle would be a bit.. off.. I never got black smoke (little puffs here and there, as to be expected), but the car ran strange until it was warm enough outside for proper combustion. I didn't know what the hell was going on until I consulted our local tuner. I guess this is a common occurrence for cars that aren't boosted factory.
Hmm that makes sense. I didn't think it would be THAT rich though... it's hitting max rich on the wideband, not just a little rich. I got 220 on my last tank, which is TERRIBLE lol.
 

TokyoSkies

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Hmm that makes sense. I didn't think it would be THAT rich though... it's hitting max rich on the wideband, not just a little rich. I got 220 on my last tank, which is TERRIBLE lol.
That is definitely running super rich. Sounds like the Wideband is fouled to me!
 

XpL0d3r

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Fixed the ECU issue.. car is running normally! Wideband sensor s**t itself though -_-
 

emerican

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glad to hear the car is running right
what did it end up being with the ecu?
sorry to hear about the wideband good time to get a better one though
 

XpL0d3r

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glad to hear the car is running right
what did it end up being with the ecu?
sorry to hear about the wideband good time to get a better one though
Yep haha. The conversion harness was loose. The ECU was put in upside down so it was actually resting on the harness / wires.
 


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