Intermittent rough idle
10-23-2016, 10:25 PM
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Racer
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Join Date: Oct 2014
Location: Columbia, Missouri
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Intermittent rough idle
Over the last couple weeks I have had a rough idle after warm up on my '80 US A/T. I sounds a bit like it is pulsing or maybe missing. I don't see any change in RPM on the tachometer. The oil pressure drops a 0.25 to 0.5 bars each time it pulses or misses. I first noticed this issue after I cleaned the grounds on the front near the headlight arm 
They needed a good cleaning. I have also had some loss of power and surging over 4,000 RPM. I found that my WOT throttle microswitch is opened when fully released and fully engaged. But when it is slightly engaged, it closes. Before I go diving into pulling plugs, doing compression tests, etc., could this cause an rough idle? I understand the WOT switch turns off the O2 sensor input. Does this mean my O2 sensor is off with a 12% fuel increase at idle? I thought the idle would hunt with out the O2 sensor. Thanks in advance.
They needed a good cleaning. I have also had some loss of power and surging over 4,000 RPM. I found that my WOT throttle microswitch is opened when fully released and fully engaged. But when it is slightly engaged, it closes. Before I go diving into pulling plugs, doing compression tests, etc., could this cause an rough idle? I understand the WOT switch turns off the O2 sensor input. Does this mean my O2 sensor is off with a 12% fuel increase at idle? I thought the idle would hunt with out the O2 sensor. Thanks in advance.
