1992 Chevy Astro Why

1992 CHEVROLET ASTRO
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HARLEYMAN1075
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Engine Performance problem
1992 Chevy Astro V8 Two Wheel Drive Automatic

I have a 1992 Chevy Asto that has a 350 TBI motor in it. When it idles it idles up and down (irrationally idles). Also when driving it wants to fall on its face. I have checked vacuum lines, fuel pump, and the timing. What else could be wrong?
Jul 9, 2010 at 12:17 PM
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JACOBANDNICKOLAS
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Since the 350 isn't factory, it could be a thousand things. Was the computer replaced when the engine was? Have you checked things like the throttle position sensor? Has a check engine light come on?
Jul 10, 2010 at 10:01 PM
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HARLEYMAN1075
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[quote:b6aa27c44b="Jacobandnickolas"]Since the 350 isn't factory, it could be a thousand things. Was the computer replaced when the engine was? Have you checked things like the throttle position sensor? Has a check engine light come on?[/quote:b6aa27c44b]

The computer was changed when we put the motor in. The trottle position sensor is new. And my check engine light is not on. I checked the injectors, fuel regulator, and vaccuum lines. This is a new problem.. It just started doing it.. the motor has been in the van for a year now. we put it in the van in 2009.
Jul 12, 2010 at 10:45 PM
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JACOBANDNICKOLAS
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The only things I can think of are the TPS, IAC, or even the EGR valve. If there are no vacuum leaks, it has to be one of the things I mentioned.
Jul 16, 2010 at 10:56 PM