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  #16  
Old August 19th, 2020, 15:31
efjellanger efjellanger is offline
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Re: Throttle hanging

Started it up today after trickle charging, and it idled just fine, drove, parked, turned off and restarted, came back home. Once home I left it idling and checked voltage at the battery. With the A/C on at idle it was low (12.5 V), after I turned the A/C off it was still low (12.8 V). Even when I revved it up to maybe 3000 RPM, it showed only about 13.6 V. I think it should get up to at least 14? This would seem to suggest at highway speeds it's never able to charge properly.
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  #17  
Old August 24th, 2020, 09:29
efjellanger efjellanger is offline
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Re: Throttle hanging

I replaced the alternator yesterday and now it's getting over 13 V sitting at idle, comfortably above 14 V at normal driving revs. So far the idle has been normal now, I may still have some issue with the throttle body sticking, we'll see.
So the picture I have now is the old tired alternator was providing almost enough juice, but not quite enough. The battery would slowly discharge over the course of a couple weeks, until the PCM would start idling high to keep the volts up, it would still not be enough and the charge would eventually get too low to crank the engine.
Can anyone verify the PCM would try to raise idle in order to provide enough voltage?

The lesson I think I take is to make sure you're getting enough voltage before doing any other electrical troubleshooting. Lots of you knew this already but sometimes I have to learn things the hard way.
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  #18  
Old October 12th, 2020, 11:06
efjellanger efjellanger is offline
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Re: Throttle hanging

Final update in case anybody's been losing sleep:


Throttle kept hanging, so I wound up replacing the entire throttle body with a junkyard unit from Ebay. It came to me with all 3 sensors so now I have extras. It was dirty so I had to clean it up before installing. Now the engine has been reliably returning to proper idle so far.


The alternator and battery still seem perfectly reliable too.
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