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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: joshcr30 on October 30, 2021, 11:34:38 AM

Title: smoke out of both exhaust ports
Post by: joshcr30 on October 30, 2021, 11:34:38 AM

i’ve got a 87 350 tbi with true dual exhaust, so i can tell smoke is mainly coming out of the passenger side, but when i rev it it gets thicker and comes out of both sides albeit more out the passenger side still. it’s not a ton of smoke, but definitely not a normal amount of just condensation. i’ve replaced the cts, egr valve, pcv valve, oil looks good, injectors are pulsing at idle, about to do the ecm, but i’m doubtful. it doesn’t smell like oil, smells like fuel and has a blueish tinge to me but my father says it looks more black to him. any help would be appreciated

Title: Re: smoke out of both exhaust ports
Post by: bd on October 30, 2021, 11:53:31 AM

First off, stop throwing parts at it!  Are you a long-time owner and the exhaust smoke is a new development?  Are you alarmed by smoking at cold start-up, or is this after the engine and exhaust system are at operating temperature?  When first started cold, is there an initial puff of bluish exhaust smoke that then turns white until warmed up?  Is the check engine lamp on?  Are there any trouble codes stored in ECM memory?  Does the ECM have an aftermarket PROM installed?