Backfire when warm and downshifting

[Prince95GT]

I have noticed that the car seems to backfire or what seems to sound like so very deeply when slowing down for a light why is this?

 

[Prince95GT]

its kind of like a deep growling popping sound

 

[HISSIN50]

When does it happen? As you kick the downshift or after you are in gear and are letting the engine do the braking?

 

[1TallMF]

What's your base timing set at? When I was playing around with mine a while back, it would backfire badly at 6* BTDC when I was slowing down. I put it up to 12* and have had no issues since. But you'd also notice a great loss of power and throttle response if this were the case. Does it seem like its running rich?

 

[Prince95GT]

When does it happen? As you kick the downshift or after you are in gear and are letting the engine do the braking?

yeah its when I let the engine do the braking

 

[smitty_64]

Mine does the same thing. I figured it was normal. Not really a backfire, but more a gurgling sound, right?

 

[HISSIN50]

It can be kinda normal, especially with no cats (they muffle the pops). You could try to clean your IAC to help the dashpot function out a little.

Otherwise, it's kinda normal - you shut off all the air to the motor and are still making it pump. This leads to a rich afterfire occasionally.

 

[Roland69]

mine does this aswell