I have just replace both head gaskets on my LT1....i also install a set of pacesetter mid length headers while at it. However now after putting everything back together...the engine is backfiring really badly and iv noticed one header getting much hotter then the other.....bent valve....spark plug wires crossed...something else?....wouldn't a bent valve clatter loudly? Backfiring goes away IF i throttle it any higher then idle...

 

valves adjusted too tightly?

 

Well...the first time around i had the valves too lose....i did the spin the pushrod method but forgot to do that extra 3/4 turn after the pushrod started dragging....so i thought that was causing it.....took it apart again and started over....this time adding a 1/2 turn after the pushrod started to drag....idle seems smoother now but im still getting the backfire....also the driver side header is getting hotter faster then the pass side....i still want to go back and check the plug wires again...maybe i crossed one of them

 

little tip take a can of wd40 and spray a small dot on all the header pipes, if you do have the plug wires crossed the wd40 will not burn off as quickly, or if it is a miss it will help you isolate the problem since your saying on side is hotter than the others

 

Thats a good idea...im gonna try that...my guess is the cooler header is where the problems at?

 

Something else?Is the air pump hooked up properly?That is what keeps the car from backfiring during deecceration.Cause the injectors are still pumping gas and are might be the problem.beer time,gotta go.Myo2.

 

well we found plug wires crossed on the passenger side. fixed it and it ran fine last night, headers were equally hot..

he drove it this afternoon and says the backfire is back and it seems like its misfiring...

 

Sorry, this isn't the case. The air pump only operates during start up to heat the cats up faster. It doesn't act to stop backfiring on deceleration....

 

Incorrect. The AIR pump is used for a couple minutes at startup to help the cats heat up faster. After that it shuts off and does nothing. The PCM knows when the throttle closes, and cuts the injectors to prevent excess fuel in the exhaust. Only restarts them when the engine costs down to low RPM.

Might want to lay off the beer.