[mikebunch]

My '65 coupe has recently started backfiring while slowing down in 2nd and 3rd gear. When I step on the clutch it stops.
My timing and points were good to go, and there is no problem accelerating.
Any help appreciated.
Thanks, Mike

[thetvirus]

Is it really backfiring like a loud boom? Could just be if you have mufflers with fiberglass packing, and the inside of muffler recently bit the dust making it louder...

[mikebunch]

It's more of a popping sound. The exhaust sytem is new, so I hope it isn't shot.

[Print Dad]

Originally Posted by mikebunch

My '65 coupe has recently started backfiring while slowing down in 2nd and 3rd gear. When I step on the clutch it stops.
My timing and points were good to go, and there is no problem accelerating.
Any help appreciated.
Thanks, Mike

Hello Mike,
When you say backfire....is it in the carb or in the exhaust.
Are you talking about when downshifting?

When you downshift, it builds pressure in the heads and causes back-pressure.
If it is through the carb ...first check the PVC valve and be sure it is free. (shake it)

It is more likely in the exhaust system however and this could be a characteristic of the muffler.

We need a bit more info..... Print Dad

[mikebunch]

As far as I can tell it's through the exhaust.
It happens when I'm in 2nd or 3rd with my foot off the gas as I slow down.
When I step on the clutch it stops popping.
Any advice appreciated!