my truck will only run if the check engine light is on

1989 CHEVROLET TRUCK
155,000 MILES
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JMKASINGER1
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the truck will start fine, but if the check engine light dosn't come on it will die within 10 seconds. but if the check engine light comes on and stays on it will run all day, but it runs very rich when light is on.
Jan 12, 2012 at 6:17 PM
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JDL
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How long since a tune-up? Any applicable trouble codes? You may need to check voltage and grounds at computer?

If it refuses to start, do you have spark, engine cranking? If you have spark, check fuel pressure and injector pulse.
Jan 12, 2012 at 7:03 PM