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-   -   '86 coupe O2 test (https://www.corvetteforums.com/forum/corvette-c4-forum-14/86-coupe-o2-test-3968/)

mech259 11-22-2006 09:39 AM

RE: '86 coupe O2 test
 
Well, really you shouldn't need it. 1st, you need to unplug your sensor, KOEO, check voltage on harness side of connector. GM sends a bias voltage to the O2 and measures reaction against it. Check for DC volts around .2v to .5v . If you are not getting bias voltage, then you have probably one of 2 things. Either there is an open to the ECM or the ECM is trash. Might need to pull the ECM out and do a circuit check from O2 to connector. Do you have a pin out of the ECM connectors? :)

rwolak 11-22-2006 09:59 AM

RE: '86 coupe O2 test
 
Ok, clue me in. KOEO????? I looked at the ECM yesterday and, as far as I can tell, I don't have a pin out of the ECM connectors.

mech259 11-22-2006 11:35 AM

RE: '86 coupe O2 test
 
KOEO .... Key On Engine Off... If you have a fax number available, PM it to me and I will fax you diagrams and diagnostic procedure. [8D]

BigRed90 09-19-2007 11:55 AM

RE: '86 coupe O2 test
 

Old post but relevant.I just did the warm up test..after a few minutes the voltage from the o2 sensor moved up to about .68 to .71 and just kind jumped a little up and down from time to time,+/- .03v .I doubt the vacuum test with the brake booster line would work on a non MAF car,but I tried anyway and the voltage didnt move much.I then blipped the throttle same thing..not any real noticeable voltage increase.I then gave a quick,small spray of starting fluid and the voltage jumped a little to like.79v.The reason I'm doing this is the car is running rich,does this sound like the O2 sensor needs replaced? It's a '90 with about 110,000 on it.The voltage from the ecm was steady at .4v also
Thanx for any help

cwb 09-19-2007 02:48 PM

RE: '86 coupe O2 test
 

ORIGINAL: BigRed90


Old post but relevant.I just did the warm up test..after a few minutes the voltage from the o2 sensor moved up to about .68 to .71 and just kind jumped a little up and down from time to time,+/- .03v .I doubt the vacuum test with the brake booster line would work on a non MAF car,but I tried anyway and the voltage didnt move much.I then blipped the throttle same thing..not any real noticeable voltage increase.I then gave a quick,small spray of starting fluid and the voltage jumped a little to like.79v.The reason I'm doing this is the car is running rich,does this sound like the O2 sensor needs replaced? It's a '90 with about 110,000 on it.The voltage from the ecm was steady at .4v also
Thanx for any help

The O2 sensor on a properly tuned car does just about zero.

Exactly what all is going on with the motor, besides the rich burn?


And welcome into the forums there!


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