396V8

Hi all

still tuning the engine....

when i started, i noticed, that my BLMīs was always on 108, not moving up...i leaned the engine in the VE tables, that it nearly stumbled out, still no movement.

i take a look at the datalogs, compared to others, and i noticed, that the "forest" of o2 voltage up and downs was more dense at .900 V than on the low side...

i changed the o2 sensor to a brand new one, adjusted the ve tables slightly and i was on 128 in idle...

my questions now...

can a o2 sensor goes bad and show always rich, although exhaust gas isnt? (seems it can)
the sensor showed good cycling (obviously ok....somehow rich side was preferred)

i found this very informative paper http://www.autodiagnosticsandpublish...or-testing.htm

point #9 says it pretty clear..

so, that would make perfect sense for my problem...

sensor reads very rich, blm goes down to take fuel out...
the car ran great in this way, also WBo2 showed good numbers...it seems, that i was just on the very edge, and the VE was spot on with the outtaken fuel...

will do it over once more, hopefully the 128 thing will work for now

my cam have 66° overlap, so thats not extrem for an ī727 ecm..


anyone agreeing?
would be good, just for peace of mind..

thanks

RBob

iTrader: (1)

Yes, had it happen to me. The O2 sensor was poisoned with silicone and reported rich. Drove the BLM & INT down so far that the engine would cut out.

RBob.

396V8

ok, im not alone!

thank you

EagleMark

Wondering if it was poisoned with silicone (or another chemical) if it effected the WB O2 sensor as well?

Could it be cleaned? Or are they ruined after silicone?

Or was this one just a faulty O2 sensor?

Another guy had the same thing that happened here with a Denso O2 sensor ordered from RockAuto and shipped to Finland. It was just a faulty O2!

396V8

Hi

my wbo2 is not poisoned for sure, i install it only for tuning the engine, the nbo2 is permanently in the car..

my guess is, that the nbo2 have seen traces of acetic acid that comes from gasket making silicone..(i know, there is sensor safe silicon available, but the acid based silicon is much stronger bonding to metal)...

the nbo2 was functional before, after rebuilding the engine and test driving, it did nothing...

always something new to learn ....