1994 Chevrolet Silverado 350tbi Engine Truck S Idle Little Rough Bad Driving

1994 CHEVROLET SILVERADO
142,000 MILES
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TRISTANBOYD
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350TBI engine.

The truck's idle is a little rough but not bad. driving the truck at 45mph or slower is not a problem as long as we are easy on the pedal. If we try to give it gas as to pull into traffic or drive any faster that 45ish, it sputters and bucks and seems to be missing severely. It has no power really. We have already changed the ECT sensor and tried a few different MAP sensors with no luck. We test the TPS with a multimeter and it appears to be functioning properly and now we are at a loss. Gas mileage is bad, no power and its occasionally smoking black.
Jan 13, 2013 at 8:03 PM
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ASEMASTER6371
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i bet you have a bad cat converter.

have the back pressure checked.

Roy
Jan 13, 2013 at 8:45 PM
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TRISTANBOYD
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Forgot to mention, there is no cat on this truck.
Jan 13, 2013 at 11:38 PM
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ASEMASTER6371
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ok, still look for exhaust restriction in the system

Roy
Jan 14, 2013 at 12:06 AM
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TRISTANBOYD
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We couldn't find any restricitions in the exhaust. Free flowing and loud like always. Gotta love a catless system with flowmasters. Anywho, what would you suggest us trying next?
Jan 17, 2013 at 4:13 PM
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ASEMASTER6371
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lets start with basics.... compression, fuel pressure and spark.

verify all 3 are good and we go from there

Roy
Jan 17, 2013 at 11:06 PM
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