flames from exhaust..
Thread Starter
Racer
Joined: Nov 2004
Posts: 445
Likes: 0
flames from exhaust..
Just finished installing a MagnaFlow exh. system on my 73 big block.
A buddy was following me and he noticed flames coming out from the mufflers while decelerating. I also could hear a popping/backfiring sound.
I haven't had the car long, but it seems to be bone stock.
With the stock exhaust there were no issues.
Do I need to make adjustments to the carb with the seemingly free-er flowing mufflers?
Also, I have attempted to check the ig. timing and cannot see the tab on the timing cover.
Do I need to remove the p. steer pump and/or idler pulley to access the tab, or is there another way that I am missing?!
The tab is there on the t. cover, as it is visible from under the car..
BTW the car starts and runs fine with no ping...just wanted to check.
TIA
A buddy was following me and he noticed flames coming out from the mufflers while decelerating. I also could hear a popping/backfiring sound.
I haven't had the car long, but it seems to be bone stock.
With the stock exhaust there were no issues.
Do I need to make adjustments to the carb with the seemingly free-er flowing mufflers?
Also, I have attempted to check the ig. timing and cannot see the tab on the timing cover.
Do I need to remove the p. steer pump and/or idler pulley to access the tab, or is there another way that I am missing?!
The tab is there on the t. cover, as it is visible from under the car..
BTW the car starts and runs fine with no ping...just wanted to check.
TIA
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Could be a stuck float causing the carb to dump excess gas or the timing.
The timing tab should be able to be seen from above the car without need to remove the items you mentioned.
You are getting gas in the exhaust which is then being ignited, probably by the heat.
The timing tab should be able to be seen from above the car without need to remove the items you mentioned.
You are getting gas in the exhaust which is then being ignited, probably by the heat.
Tech Contributor
Joined: Aug 1999
Posts: 14,379
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
When you free up the exhaust system, the engine leans out, especially on deceleration when you slam the throttle closed. This causes a lean misfire on random cylinders, and these misfiring cylinders will pump unburned air/fuel mixture into the exhaust, where it then ignites and burns. You need to richen up the carb - start by running the idle mixture screws a little richer. If that doesn't do it, richen the carb up 2 jet sizes and then re-tune idle mixture.
Lars
Lars
