what would cause a valve to stick open? its on a custom deluxe truck of a friend of mine. hes getting no compression in one cylinder but all the other are 1psi from each other so...its backfiring when he gets on or off it so maybe its a intake valve stuck? what could we do to fix this?

 

Bent valve?

Pull the valve cover

 

sounds like either a bent or burnt valve. either one will require pulling the heads off. good luck. its not a hard job at all but just a pain in the ***.

 

'74-older engine?

Soft valves & seats + unleaded fuel = burnt valve.

 

thats the problem we have no idea how old or what this engine came from...bought it with the motor in it. started life as a 4.3 TBI but now its a 350 with a edelbrock intake and holley carb...thats all we know i havent had a chance to take a look at it close yet but hes talking about buying some heads for 200$ for somebody isay we just fix it if it isnt to hard