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Black Smoke...

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3.8K views 4 replies 3 participants last post by  Revredneck  
#1 ·
Hi Guys,

So i have a 2001 GMC Sonoma with a 4.3 V6. That is now sluggish on take off and blowing black wet smoke out the tailpipe. The code scanner is saying it detected a random misfire has anyone had this problem before??
 
#2 ·
Black smoke is usually a sign of incomplete combustion. Could be from a poor, or no, spark; could be from too much fuel in the fuel/air ratio.

If the code reader is saying you have a mis-fire, that's the place to start.
Are the plugs old?
What are the condition of the plug wires?
Condition of distributor cap (I think the '01 used a cap)?
 
#5 ·
If I were you , I'd put a fuel pressure gage on it first. Key it on and check the pressure, then make sure it holds pressure when off. It sounds to me like your fuel pressure regulator is leaking pressure and fuel into the intake.
Good Luck and God Bless