93 250 5.8l

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Dec 13, 2008 | 11:17 PM

jellybean66

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From: Tobaccoville

93 250 5.8l

At idle speed, what would cause the engine to lope and at the same time the voltmeter will pulse from about 13 to 17?

Dec 14, 2008 | 05:05 AM

Opossum

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From: Renton, WA

A bad alternator/voltage regulator

Dec 14, 2008 | 02:31 PM

jellybean66

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From: Tobaccoville

Thank you. Wanted to confirm what I had suspicion of.

Dec 14, 2008 | 06:12 PM

Conanski

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From: Ottawa, Ontario

I doubt the 2 things are related actually.. but who knows. Lopey idle on these things is ofen related to a dirty IAC valve and/or weak spark. If the alternator has a bad regulator the voltage will always increase with rpm.. which should be pretty obvious.

Dec 15, 2008 | 04:14 AM

Opossum

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From: Renton, WA

Quote:

Originally Posted by Conanski

Voltage should still never go over 14.5, so many of the sensors are voltage sensative that such a big swing in voltage could be playing havoc on them, noy to mention the huge variation in drag on the engine. Bottom line he has a bad voltage regulator, which on his truck is internal with the alternator. The lopey idle will probably go away when the regulator is fixed if not he can then address that but the alt needs to be fixed first.