I have noticed the wideband does not read unburnt/raw fuel through the exhaust. I think depending on the condition, misfires can show up a lean reading on the meter. Would that be correct?

 

It depends on how much the WB output has been filtered. At low engine speeds a single cylinder with a lean misfire (such as just after a cold start) is easily seen as a lean spike. If heavily filtered that spike may be lost.

At higher engine speeds a lean condition on all cylinders (not enough fuel) can have a WB bouncing off the rails. It will show from greater then 25.5 AFR to less then 10.0 AFR and back and forth.

RBob.

 

Ok, well I was messing with my cold start trying to get the a/f right. The wideband reports 20.0 as my mixture the whole cold start(no matter the pulse width). I suspect it is lean misfires caused by my old plugs.

On a sidenote my friend was having problems with his car backfiring through the intake under heavy load cruising(t-56/MR). I tuned the chip so the fueling didn't change. There was a few holes in the main spark table in the 85-100kpa area @ 1000-2600. I fixed the timing and the bog/pop was gone. Now that I look at the log data, the blms are very lean. I know the ve tables are really, really close. Nothing was changed since the last time I logged data. So I'm thinking misfires will show a false lean condition on the narrowband O2(just like the wideband). In turn I think he needs new plugs...... they look a bit old and glazed. Rest of ignition is fine.

So do you agree that a fouled plug can create a false lean through an O2 sensor?

 

Tim, when I have bad plug wires causing a missfire the would instanly show on WB and stock o2 as a lean condition because of the unburned 02.

 

that is exactly what I thought. Didn't want to ASSume it though. Very important thing to know


So how is the t/a doing?ever bust a sub 1.5 60ft?

 

NAA , NOT YET.
The converter that I sent back before that TCI said there was nothing wrong with finally stopped locking all together. grrrr
Also found it was stalling around 5100 - engine is over powering it.
That would explain why it won't hook - I have since installed 90/10's and hoosier 27 x 11.5 QTP's and still no good, If you leave soft it pulls wheels real nice - then spins.
I have made about 15 passes this year , Not one pass have I not spun from stk susp. to where I am now.
If you leave hard its all spin before any transfer takes place.
So now they are sending me a brand new Super street fighter with a 12" lock disc that weighs 4 lbs more . That converter is rated around 3800 but should give me about 4200 at full torque seeing as how I was stalling later on the other 2.
Just hope that 4 lbs on crank does not hurt me.
Its so fun pulling out your tranny about 6 times a year. The up side to that is I got her down to below 1.5 hrs to change a converter.
Hmm, wonder if John Force is looking for a tranny changer