02 voltage and maps 3.5 v8

[Hybrid_From_Hell]

^^^

What he said

Mine - <cough> Too much Shiraz

Nige

[Hybrid_From_Hell]

Nige

[gav-]

I have now moved the lambda probe to the new location, and still no difference. The gauge for the front bank o2 sensor does move when I slowly rev the engine and when i release the throttle it reads approx 0.6v for a second or so.

When the engine is idling, the gauge reads approx 0.22-0.25v and this corresponds when a volt meter is put across the signal and earth wire at the lambda sensor.

I have checked the sensor with a blowlamp and that reads ok, and also checked the outer casing of the sensor with a temperature gun when power is supplied to the white wires of the lambda sensor. It reaches 150deg C. I have also noticed a very very small leak on the exhaust manifold (can just feel it against the hairs on the back of my hand). The could possibly be adding some 02 into the exhaust. I will fix this when it has cooled.

I also noticed that with the lambda completely disconnected from the ecu the front bank 02 sensor reads 0.2v on tunerstudio. I have played around with various earths but they make no difference. So it would appear I have a 0.2v error already. Checking the voltage between battery earth and engine earth there is a 0.08v voltage difference.

Is the lambda actually working ok? What would yours typically read when idling (I dont run the engine long as the neighbours dont get too happy, but the coolant temp reaches 70degC.)

I am thinking of investing in a wideband now as this would help me out- The car is not road legal (installing megasquirt was the first stage to get it on the road) but i guess with a wideband I can do some tuning on idle and in my garden!! (bear in mind that the iva test is a stand still CO test, which is all i need to pass initially!)

[gav-]

one thought i have had is whether the engine is running rich, when the engine backfire it affects the lambda probe as it doesnt like the backfire situation and then as a result reads a lean number.

It doesnt answer why when disconnected the gauge still reads 0.2v

[FridgeFreezer]

Try connecting the gauge wire from the MS to the sensor ground, should get 0v.

I'm assuming all your sensors are grounded back to the ECU plug as per my last post.

[gav-]

yes fridge all the sensor grounds are connected to the ECU grounds. I put the lambda signal wire from the ecu and one of the grounds from the ecu together yesterday and it still read 0.2v.