A question for the electronic gurus
Submitted: Friday, Mar 18, 2005 at 16:03
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cwebb
Hi all
I am wanting to
check some vital engine components with my multimeter (o2 sensor, air flow etc). The manual states what the expected resistance should be. How can I verify the accuracy of my multimeter, short of buying a resistor or something from DSE to
check? Or perhaps this is the solution?! I have asked a workmate to borrow his Fluke multimeter as a reference, but then how do you
check the accuracy of his?
I've reason to believe my second vehicle (RB30e engined Skyline) has some engine issues, and am sure that due to its very high mileage that it is a critical sensor as opposed to my pretty good servicing record.
Thanks in advance
Chris
Reply By: hl - Friday, Mar 18, 2005 at 17:44
Friday, Mar 18, 2005 at 17:44
Hi,
You can't
check the oxygen sensor with a multimeter properly. You can get some idea by putting a high impedance analog meter on it while the engine is running, the voltage will be quite low, but the important thing is it should vary between zero and whatever it is about 6 to 10 times in ten seconds.
A stuffed oxygen sensor actually has not a great effect on engine performance. It might idle a bit rough, but that is all.
As for the airflow meter, if it is the bosch as used in the VL commodore, you can see the wire in it glow briefly when you turn the ignition on or off. If it does that, it is probably ok.
Cheers
AnswerID:
102948
Reply By: Mike Harding - Friday, Mar 18, 2005 at 17:46
Friday, Mar 18, 2005 at 17:46
If you have a Fluke meter then for your application I wouldn't worry about it's accuracy providing it reads less than 0.5R when you short the probes and open circuit when they are open circuit it will be
well good enough for your requirements.
The oxygen sensor is a consumable item - I cannot remember their expected life but it _should_ be replaced at some point, a Google search will indicate when. I'd be a bit doubtful of the value of a simple resistance reading to tell me the health of an O2 sensor - they are a pretty complex bit of engineering.
Mike Harding
AnswerID:
102951