350 back fire problem

[Jesse80]

While I was waiting for parts to be delivered for my G body, I decided to tinker with my dads 79 3/4 tin Chevy plow truck. He had purchased some headers from summit a year prior just never got around to installing them. So I decided to do it for him.
His current stock manifold had no gasket on the passenger side and the donut gasket was completely gone, drivers side was all there and good. Well the job is finished now but upon starting and letting it idle for about 10 seconds (from what I can tell) the passenger side is popping/backfiring.
I don’t know if it was doing it prior because the exhaust was so loud it sounded like open headers. I have changed plugs and wires, new p/s belts, new alt and fan belt, new bolts in the loose steering gear box. None of that should have affected the backfire issue tho.

 

[84slow]

Double check the wiring order and check if the boots are all in

 

[Jesse80]

rechecked to make sure the plug wires were tight and on the correct cylinder, but thanks for the thought 84slow.

 

[MrSony]

Pull a plug wire off one cyl at a time while running and see if it changes, putting it back on of course.

 

[pontiacgp]

warm up the engine and use a infared heat thermometer to check the heat on each exhaust tube to see if any are running cooler. If you find any runner cooler remove the plug and take a good look at it. It could be the ceramic is cracked and grounding the plug

 

[MrSony]

warm up the engine and use a infared heat thermometer to check the heat on each exhaust tube to see if any are running cooler. If you find any runner cooler remove the plug and take a good look at it. It could be the ceramic is cracked and grounding the plug

I'm poor so I use the squirt bottle method, or a water bottle with a hole in the lid. Whichever one sizzles the most or the least is usually the culprit. Only works with headers though, or I guess individual runner manifolds if they're long enough.

 

[pontiacgp]

I'm poor so I use the squirt bottle method, or a water bottle with a hole in the lid. Whichever one sizzles the most or the least is usually the culprit. Only works with headers though, or I guess individual runner manifolds if they're long enough.

yes, the method with a thermometer works with headers........as for the water spray I have use that at night and looked for sparks and that does work.