I have a 86 iroc TPI 305, I just put hedmen headers on her and acdelco rs43ts the ones in the book, first i put the 44s in and it didnt run right, when i yanked them all out one wasnt firing, Now I put the new ones in and it ran fine for alittle bit but now does the same thing, It idles fine no back firing but when i put into gear it starts. When I had it on the road when it got up to 5200rpm the intake would also sound like its back firing. ANY HELP please this is my baby. lol

 

double check the wires it sounds like you have two crossed firing order 18436572 clockwise very easy to cross the wires ,later jimmy

 

I dont think its crossed wires cause i took them off one at a time when i put the new plugs in, Could it be that I put the o2 sensor to close to the primaries? like I put in on the collector. I also cut the wire and extended it. It has power it just pops when I step on it and its reaches higher rpm, It back fires while in gear.

 

do you have the exhaust hooked up? or just straight headers?

 

exhuast is hooked up.

 

o2 sensor should be fine then,jimmy

 

Describe "backfire".. sounds to me more like pops and bangs in the exhuast.. especially if it is happening when you let off at high rpm.

 

ok I found out what the prob was I had the wires crossed, Let the flaming begin! lol, she now runs fine and doesnt pop or anything. Thanks for the help guys.

 

Happens to the best of us. Glad you figured it out.

 

no flaming from me ive been doing this for over 35 years its very easy to do ,good job ,later jimmy