Some causes of backfire

**chuckie669** · 05-19-2008, 05:48 PM

What are some of the causes for backfiring?

I notice a backfire/pop when I go med to heavy accel on the throttle and then shift gears. Don't notice everytime but it can be annoying.

**0rion** · 05-19-2008, 08:28 PM

does it do it when you push the clutch in and let off the gas? Sounds like you might be describing the exhaust popping which is normal with free flowing exhaust. What exhaust set up do you have?

**LS2Tuner** · 05-19-2008, 10:36 PM

You didn't state if it is coming out the exhaust or intake. Sounds like you are talking about the exhaust though.

If it is the exhaust there is a couple different causes such as a leak that is letting oxygen in or a rich condition that causes excess fuel in the pipe's. Do you have some large chrome tips.......?

If it is out the intake it can be caused by a lean condition,off timing, and or a cam lobe going out.

Or as Orion stated it could be resonating out the exhaust too.

**chuckie669** · 05-20-2008, 03:18 AM

I was speaking about the exhaust. Well, I do have the LM1 exhaust which is definitely more free flowing, so I'll go through and check to see that everything is tight.

I do have a similar sound if I drive the car immediately after startup which happens maybe 2-3 times a year. when I shift from first to second it gave a single pop and I would never hear it again.

**0rion** · 05-20-2008, 06:07 AM

It's your exhaust popping.

**Spaz** · 05-20-2008, 06:38 AM

Originally Posted by 0rion

It's your exhaust popping.

**01ws6er** · 05-20-2008, 11:25 AM

Originally Posted by 0rion

does it do it when you push the clutch in and let off the gas? Sounds like you might be describing the exhaust popping which is normal with free flowing exhaust. What exhaust set up do you have?

Mine does it every so often on upshift at higer rpms, but mostly when I'm in second and just coasting to a stop and letting the pressure build up so that when I push in the clutch it crackles/pops (god I love that sound)...

My two buddies with t/a's have the same pop as well.

**Spaz** · 05-20-2008, 11:32 AM

Originally Posted by 01ws6er

Mine does it every so often on upshift at higer rpms, but mostly when I'm in second and just coasting to a stop and letting the pressure build up so that when I push in the clutch it crackles/pops (god I love that sound)...

My two buddies with t/a's have the same pop as well.

that is normal...

and it sounds damned good!!! i like to rack second at about 3500 rpm with no brake and slow down that way...

"RRRRRRRRBAPbappbabpbpapbpbapapbpapbppbpaptbpbtapp bapabparrrrrr..."

**chuckie669** · 05-20-2008, 02:45 PM

yeah, but it's not the lm kind of popping as spaz points out above. It's usually just one pop when shifting up and is kind of annoying.

I'll try and tighten everything up and check it over. Thanks guys.

**jigger1166** · 05-20-2008, 02:56 PM

I think it's just your exhaust. I installed the LM, and didn't like the way it popped, and snapped. So I swapped the resonator for the LM II muffler. It sounds better to me.