Occasional High Idle Speed - $8D 383 fully modified TPI

[JeepsAndGuns]

I can not speak for all of them, but on the 4 wire bosch sensor I used, the heater element wires were both the same color. In my case, both were white.

[zaut]

I got the three wire O2 yesterday. Two wires were black an the other was blue. The two black wires read 15 ohm between each and open to the blue and the O2 case. The blue read open to everything, like the old single wire O2 I was replacing. I connected the two black wires to the heater circuit and the blue to the O2 input. Everything is working fine. I have not been droping out of closed loop and have ajusted my closed loop timer to very short times and so far all is good.

[zaut]

On another area related to the O2 sensor. I kept the air injection system on the car. I see a scalar for Air Divert O2 rich/lean reduction in millivolts. Does this offset the point where the EMC thinks the AFR is when air is being pumped into the exhaust headers? If so, is there a way to determine if the value in the scalar is correct?

[RobertISaar]

yes, that's what it is for, essentially a correction since the O2 sensor is mounted after the AIR introduction point, so it will read the true AFR plus the external air being injected.

to correct it, if it's needed, i would tune the fueling with it off, then when you have that done, turn on the AIR system and then adjust that value until the fuel trims are back inline.

[zaut]

I did tune with the AIR, EGR,CCP etc. off. Thanks to the advice from EagleMark. Now that all the emissions equipment is turned on, I do see high and low BLMs compaired to what I had tuned to. Now that I have a heated O2 sensor, I am looking into that closer. By the way, the heated O2 is great. On hot restart, I am in closed loop in two seconds and about 30 seconds on a cold starts. What I am wondering is if there is a way to see the sensor output shift when the air is turned on. Once in closed loop, I would think that the ECM will adjust the AFR as soon as it sees the shift occure. My thought is to set the closed loop timer to a very long time and the scalar set to zero; start the car until the O2 is ready then cycle the air on and off and see the voltage shift. Would keeping the engine in open loop stop the AFR adjustment that you get in closed loop? Does this sound lake a good approch?

[RobertISaar]

i would assume staying in open loop would make the ECM stop accounting for it, but i haven't checked the hack to confirm it.

think of it this way, if doing it in closed loop, you can just watch the BLM/INT react to it and then just move the AIR value up or down to get them to return to their normal values.

[EagleMark]

AIR Pump is not used that often and only open loop, like cold starts for emmissions. Some were plumbed in after O2 sensor to add air to exhaust before the CAT for added heat, not sure if this type is open loop only? So what type does your car have? What type does the new ECM and bin have? I ask because I vagely remember an AIr pump system that did pump air during decel?

In Open Loop there is no fueling adjustment. Watch your BLM and INT should be 128. It runs strictly off VE table with no adjustment.

High and Low BLM changes will occur after a tune is done do to weather changes.

[RobertISaar]

having the AIR pump run before the O2 will actually help heat it up faster...

now that i think about it, that offset may be for entering closed loop, since to do so, the O2 voltage has to go so high or so low compared to 450mV.... perhaps it takes ~100mV away from that requirement?