O2/Fuel trim problems
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Logistics Pro
Joined: Mar 2005
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From: Mexico, Missouri
O2/Fuel trim problems
I've posted about this similar problem in the past. It was running lean it said, but in fact, it was running rich.
This problem is with my '92 302
I hooked up my DVOM to the O2 sensor harness and got a steady voltage of .91 to .85. I have done everything to this to try and figure why it is not switching. I finally tried something else besides vac leaks and sensors. On the truck, the passenger side manifold has a port for a signaling O2 sensor just as it leaves the block. This isn't correct according to my manuals and diagrams. Someone has swapped something at some point. So with the DVOM still connected and showing .87v, I pulled the unused O2 sensor for the exhaust. 2-5 seconds after doing so, my DVOM starting switching.
Now granted, it has an exhaust leak, but why does the truck run so much better now that it was removed? I'm stumped. The rolling idle has disappeared, the higher levels of unburned hydrocarbons is null.
I'm hoping someone can help with suggestions, cuz I have none to further my diagnosis.
This problem is with my '92 302
I hooked up my DVOM to the O2 sensor harness and got a steady voltage of .91 to .85. I have done everything to this to try and figure why it is not switching. I finally tried something else besides vac leaks and sensors. On the truck, the passenger side manifold has a port for a signaling O2 sensor just as it leaves the block. This isn't correct according to my manuals and diagrams. Someone has swapped something at some point. So with the DVOM still connected and showing .87v, I pulled the unused O2 sensor for the exhaust. 2-5 seconds after doing so, my DVOM starting switching.
Now granted, it has an exhaust leak, but why does the truck run so much better now that it was removed? I'm stumped. The rolling idle has disappeared, the higher levels of unburned hydrocarbons is null.
I'm hoping someone can help with suggestions, cuz I have none to further my diagnosis.
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