Yes, I saw on the oscilloscope the other day that it wasn't cycling, but it was leaning the mixture as I biased the pump positive. I am going to reset the pending fault, I think I had too much bias on when ECU ran the check. If the pending fault sets again I may abandon the effort, but not without an economy test run and biasing up the map sensor.
Oxygen Sensor P1133 No MAP, IAT, ECT, TP, Fuel trim, Misfire, Cam, 100 seconds after closed loop DTC Type B
System - Too Few EGR, CCP, Voltage and crank DTC's enable, Once per ignition
O2S R/L and L/R Closed loop
Switches 02 Voltage low threshold .300 V
High threshold .600 V
Flow > 7 g/sec
1500 < RPM < 3000
100 seconds after closed loop DTC Type B
enable, Once per ignition
0 V to 1.0 V This DTC
02 sensor switches < 10 counts
determines if the 02 sensor
is functioning properly by
checking its switches
Rationality Check
1.4 is the equivalence its the ratio compared to Lamda ~ 22:1 FAR.
Burning lean is more efficient because air has a lower heat capacity than burnt fuel products, therefore Gamma in the efficiency equation for an Otto cycle is lower. More work is done on the piston per unit of fuel because it heats the leaner mixture hotter, thus producing higher pressure. There is a limit, though because the flame speed slows down as the mixture is leaned, ignition becomes more difficult and combustion is less stable. Max efficiency is at 1.4 times more air than a stoichiometric mixture. Hydrogen, though has a much faster flame speed than gasoline and with an equivalence of over 2, has a thermal efficiency near 50%. There is a lot of research being done to develop a throttleless lean burn engine that meets air pollution standards without a catalyst by mixing hydrogen and gasoline or cracking hydrogen from reformulated gasoline. Peak temperatures in a lean burn engine are lower, thus less NOx is formed. Diesels are not lean burn engines because combustion occurs in rich areas around fuel droplets.
Where:
n = thermal efficiency
r = compression ratio
, gama, specific heat ratio
read, learn:
http://en.wikipedia.org/wiki/Otto_cycle
http://en.wikipedia.org/wiki/Lean_burn
Quote:
Originally Posted by mwebb
an AFR sensor can not be substituted for an 02 sensor
the waveform output is different
the ECM that is looking at a AFR waveform will not be happy with the waveform of an 02 sensor and vice versa .
your ECM will become angry if it does not see the 02 sensor cycling
150mv to 850mv and back in 100ms or less OR
what ever the time that is listed in
GM MODE 6 under front 02 sensor testing
-look up
"GM MODE6" select your system from the application list - study , learn.
what do this imply ? 1.4 what ?
...."Maximum efficiency for lean burn gasoline engines is near 1.4"...
|