Lambda Voltage

[ms33]

Does anyone know how to check the condition (ie voltage) of the lambda's?

Or does the car need to be connected to a diagnostic machine?

[blind_elk]

Check with a multimeter. +ve connected to the middle wire of the O2 sensor -ve to earth. Engine at operating temp.

The (standard, narrow-band) O2 sensor ranges 0 - 1V. (I think) 0 = lean, 1 = rich.

From idle, punch the throttle, O2 should go rich. Back off (snap throttle closed), O2 goes lean. Hold revs @2000, O2 should oscillate between lean and rich, averaging 0.5V. This is the "closed loop" that gets mentioned often.

Jaycar has a kit that you can hook into the O2 sensor - gives you a pretty "dancing lights" display to indicate what the O2 sensor is seeing.

[89CAL]

0-5v I think my AEM is with Bosch wideband

[ms33]

Check with a multimeter. +ve connected to the middle wire of the O2 sensor -ve to earth. Engine at operating temp.

The (standard, narrow-band) O2 sensor ranges 0 - 1V. (I think) 0 = lean, 1 = rich.

From idle, punch the throttle, O2 should go rich. Back off (snap throttle closed), O2 goes lean. Hold revs @2000, O2 should oscillate between lean and rich, averaging 0.5V. This is the "closed loop" that gets mentioned often.

Jaycar has a kit that you can hook into the O2 sensor - gives you a pretty "dancing lights" display to indicate what the O2 sensor is seeing.

Not wanting to seem thick, how do I connect the multimeter to the sensors, with the multiplugs still connected?

[Moodles2]

These come in handy: http://ecutalk.com/consultlcd.aspx

[blind_elk]

If the probe on the mm doesn't fit, you can often use an opened-out paperclip into the back of the plug, then connect the mm via alligator clips.

To measure / observe closed loop, you will need the O2 sensor plug connected, but for the others, you can unplug and measure off the O2 itself.

[Beer Baron]

forget the multimeter. you are best off just hooking up a consult/ecu-talk device. that will give you the 02 sensor voltage. will also allow you to check operation of other sensors and solenoids too. even just the consult cable will be fine (just plug it into a laptop and your consult port near the in-cabin fuses).

otherwise if you have a power FC the handcontroller will let you do the same stuff (sensor check etc).

[Beer Baron]

there you go, $80 will get you the cable with USB plug delivered to you. even cheaper on ebay etc. http://ecutalk.com/interface.aspx

edit, the chinese ones are like $30. but need serial to USD adapter if no serial RS232 port on your laptop.

[mad082]

i use an ecutalk one. definitely worth the money over the cheap chinese ones.

also, often a multimeter can't register the change in voltage fast enough.

[ms33]

Thanks for the input guys, most appreciated.

[ms33]

Little update, did the tests, and the rear lambda is screwed, so will swap it out asap.

Thanks again guys.