3.9 V6 Stalling Out

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MackieChan

Junior Member
Joined
Oct 27, 2016
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20
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Location
Canada
Ram Year
1997
Engine
Magnum 3.9
Anytime I come to a stop, a little too hard or even normally, my truck just stalls out. It's been like that since I bought it but has gotten progressively worse in the last month or so. I asked the guy I bought it from why it did that and he had no clue. Just start it again and drive off was what he did. There's the odd time where it dosent do it and the truck runs beautifully. And there's other times just putting it into gear stalls it out. I've been told to try unplugging the MAF or an O2 Sensor and driving it around the block to see if that's the problem but I'd like more input before I try that. Thanks in advance
 

Yeret

The Village Drunk
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Oct 2, 2014
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Location
Under the hood fixing/breaking something.
Ram Year
1999
Engine
5.9 Magnum
Me, I'd start with replacing the idle air control (IAC) valve. You can get one for as little as $10 on eBay. I wouldn't actually recommend running it for any length of time because they're cheesy and don't work well for long but brand new, it'll work good enough to verify if the old one is the problem or not.

Our engines don't use a Mass Airflow (MAF) sensor but rather use a Manifold Absolute Pressure (MAP) sensor. They more or less serve the same role but use different methods. Anyway, don't try unplugging it. I can verify from experience that unplugging the MAP sensor WILL kill a running engine within about 5 seconds. If it was really the problem, the engine would probably not run at all. Also, a failure within it or the circuit should set the Check Engine Light.
 

dudeman2009

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Arizona
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2001 1500 Sport with enough electrical modifications to make my brain hurt
Engine
Magnum 360
+1 to IAC

An easy way to test the IAC, when the truck is giving you problems pull the hose for the PCV valve off the intake or pull the brake booster hose and see if that fixes the problem. If it does, the IAC is bad.

Also, like Yeret said, you can get cheap ones, but they will fail quickly, you're better off getting a quality part and replacing it once.
 

dudeman2009

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Arizona
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2001 1500 Sport with enough electrical modifications to make my brain hurt
Engine
Magnum 360
It only works on vehicles with MAP sensors as they are sensing intake pressure instead of measuring the flow of air.
 
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