Backfire when warm and downshifting

Prince95GT

Founding Member

Sep 29, 2001

335

0

0

Canada

Jun 20, 2006

#1

• Jun 20, 2006

• #1

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

Founding Member

Sep 29, 2001

335

0

0

Canada

Jun 20, 2006

#2

• Jun 20, 2006

• #2

its kind of like a deep growling popping sound

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

34

129

Jun 20, 2006

#3

• Jun 20, 2006

• #3

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

 

1TallMF

New Member

Apr 17, 2006

955

1

0

Montreal

Jun 20, 2006

#4

• Jun 20, 2006

• #4

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

Founding Member

Sep 29, 2001

335

0

0

Canada

Jun 20, 2006

#5

• Jun 20, 2006

• #5

HISSIN50 said:

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

Click to expand...

yeah its when I let the engine do the braking

 

smitty_64

New Member

May 27, 2006

75

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0

Jun 20, 2006

#6

• Jun 20, 2006

• #6

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

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

34

129

Jun 20, 2006

#7

• Jun 20, 2006

• #7

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

Sergeant Tangnet

Sep 17, 2005

2,867

3

58

Port Elgin, Ontario

Jun 21, 2006

#8

• Jun 21, 2006

• #8

mine does this aswell