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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: five0roller on March 17, 2009, 12:45:03 pm

Title: Back firing adn smoke from my engine
Post by: five0roller on March 17, 2009, 12:45:03 pm

i purchased an 85 C10.  Great exterior but the engine is giving me problem.  idles very high constantly and then backfires when i shut it off.  There is a hose which runs from the left side of the air filter housing down to the engine which is melted.  I know this may not explain the problem but its the best i can do woithout a picture of it.  The Hose runs to teh exhaust manifold i believe.  I thought this was supposed to be metal.  And would this hose being detatched cause it to melt and would it cause my Idle/backfire problem?

Title: Re: Back firing adn smoke from my engine
Post by: VileZambonie on March 17, 2009, 01:03:00 pm

Post a pic. The stove pipe is metal. Do you have a.i.r.? Pix would really help. Check for vacuum leaks.

Title: Re: Back firing adn smoke from my engine
Post by: 406 Q-ship on March 20, 2009, 01:45:05 am

Sounds like just a high idle speed to me, reset the idle speed to about 700-800 RPM.  I bet the backfiring you are hearing is the engine run-on.  The hose you describe is the fresh air for crankcase ventalation, if it is in that bad of shape I bet the vacuum hose aren't doing that well either.......replace them all too (cheap insurance).