adsm08
Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
- Joined
- Sep 20, 2009
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- Dillsburg PA
- Vehicle Year
- 1987
- Make / Model
- Ford
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- 2WD / 4WD
- 4WD
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- 31X10.50X15
Almost.So since the wire isnt carrying voltage, the ECM thinks the motors lean...therefore dumping tons of fuel to compensate, therefore causing rusty the person a PITA. Correct?
That wire is a ground, so it should never have voltage. The voltage should drop across the load, which in this case would be the computer's circuit for monitoring O2 sensor voltage. But it is still needed to see the voltage.
Think of it like a hotwater-radiant heat system. You have a water pipe with a pressure gauge (voltage is electrical pressure). A pipe is burst after the gauge, but the last shutoff valve is before the gauge. You have pressure, you know it's there, but since it can't pass through the gauge without a way to return to the other side of the system, you can't see that pressure.
The hot side is your pipe to the shutoff valve. The voltmeter is the pressure gauge, and the burst pipe is your ground that isn't working.
So the hot wire is carrying the voltage, the ground is malfunctioning, and so the computer can't see the voltage, causing Rusty the computer a PITA when none of the things it does to make the O2s react do anything, making it run stupid, causing Rusty the person a PITA.
I have gone through the exact symptoms you have described in chasing this twice in my life. Both times it took me way too long to find the problem.
The first time I found my oxygen sensor broken in two. The second time that ground got damaged during an engine replacement.