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[tmsmini]

I just put my MPi engine back in after having it rebuilt and I am seeing some strange readings from the the ACR4

O2 VOLTS.BNK.1 1.95
E.C.T. : 101
I.A.T. : 63
M.A.P.SENSOR : 52.0

O2 VOLTS.BNK.1 1.91
E.C.T. : 101
I.A.T. : 63
M.A.P.SENSOR : 52.8

R.P.M. : 3033
O2 VOLTS.BNK.1 0.02
I.A.T. : 75
M.A.P.SENSOR : 34.3

R.P.M. : 2859
O2 VOLTS.BNK.1 1.94
I.A.T. : 75
M.A.P.SENSOR : 29.9

The reading is changing, but it is way out of range. It is a new O2 sensor and a new temp sensor. Is it possible that the O2 is reading correctly and some other sensor is causing the over fueling?
The car otherwise appears to be running Ok but I only have 100 miles on it and have not taken it over 3500 RPM. The rebuilder said there was were significant deposits in the combustion chambers, so the cause likely existed before the rebuild.

I guess at a minimum I could verify the voltage readings with a multimeter.

[tmsmini]

I guess my confusion results from the O2 values being listed in most locations in volts, but it appears the ACR lsts them in millivolts which still does not make sense. If I divide by 1000 I get

1.95 / 1000 = .00195

Which still does not make sense...

From Sprockets post on lambda sensors:
With the engine running, you should see the voltage go high to around 500mv and then drop to around 200mv. The time period should be at LEAST once a second (sensor is getting tiered at this point). The voltage numbers are not important as long as they go hi/low.

I guess I just do not know what scale the ACR is actually using.

Edited by tmsmini, 03 November 2008 - 05:18 PM.