C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Sluggish acceleration

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Old Mar 1, 2015 | 10:12 PM
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Default Sluggish acceleration

Hey guys..I have a 94 roadster that has become sluggish on acceleration. The gas mileage as well has gone way down and the engine is running very rich as there is black soot on my bumper. Any ideas on likely cause/fix? TIA
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Old Mar 1, 2015 | 11:50 PM
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Originally Posted by Doughan
Hey guys..I have a 94 roadster that has become sluggish on acceleration. The gas mileage as well has gone way down and the engine is running very rich as there is black soot on my bumper. Any ideas on likely cause/fix? TIA

my guess is the standard response is going to be an injector stuck open. I'd hit it with a leakdown test on the fuel rail. pressure testing kit is cheap, 15 bucks, and its fun. google how to test fuel pressure.

or

if you have an exhaust leak ahead of your (first??) o2 sensor (sucking fresh air into exhaust ahead of the sensor but after combustion has taken place), it could be thinking you have a high 02 concentration and is enriching the fuel mixture. try the leak down first.

my experience is with the L98 so not sure if its applicable.
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Old Mar 1, 2015 | 11:58 PM
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Bad plug wire. Check for arcs in a dark garage.

If you pull out the spark plugs you will probably find one that is wet with fuel because it hasn't been firing.
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Old Mar 2, 2015 | 12:06 AM
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Thanks for the replies...I will add that it sits for 2 to 3 weeks at a time as well..
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