1995 GMC Suburban running poor

1995 GMC SUBURBAN
146,000 MILES • V8 • 4WD • AUTOMATIC
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TB3
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  • 1 POST
after initial startup idols well, turn off then restart and it floods , black smoke, will run if left alone but if you give it gas it will want to die. it will run an idol fine eventually but if you turn it off and try to restart, same thing happens and gets worse when it up to full operating temp. new fuel pump, new FPR, new plugs, hand code 54 we cleared it it has not comeback in about an 1/2 hr of run time. Any idea

Thanks, Tom
Sep 20, 2009 at 8:01 PM
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RASMATAZ
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  • 75,992 POSTS
Check the fuel pressure and for a clogged return line

Running rich:

Possible causes include a bad O2 sensor, excessive fuel pressure (bad fuel pressure regulator or plugged return line), leaky fuel injectors, dirty air filter or restricted air inlet, or a defective coolant sensor that prevents the engine management system from going into closed loop mode.
Sep 20, 2009 at 9:28 PM