At least it sounds like a backfire..... Is it something I should be concerned about?

 

Mine does too. From what I've heard, its a Nissan thing.

 

i hope its not bad, but its sound pretty bad **** especially when you get some flames.

 

No its normal, if your vehicle is running rich or you have a blow off valve that vents into the atmosphere its normal.

 

Well, it is rich. But it does it while still on the gas, so I'm not so sure it's the BOV.

 

When I souped up my Turbo Volvo I had that issue, Turned out to be a fouled plug.

 

If your vehicle backfires while your on the gas then you have a spark issue. I would suggest checking your plugs and if your FI then go with 1 or 2 step colder and regap so you dont have spark blow by. Good luck

 

Thanks, I'll check the plugs tonight. Wouldn't surprise me if they're fouled.

 

mine backfires all the time now when i get on it a little bit and let off, probably about 1/3 throttle or so.

 

backfire is pretty bad for your car. the explosion happens inside your exhaust pipe and it goes toward the rear pipes and also toward your exhaust valves. u could damage the exhaust valves if the backfire is bad enuf

 

Is it really that severe? I see it most of the time on highly modded/boosted cars.

Seems to be a normal on highly tuned Supras/Skylines.

 

Mine does the same thing.....I'm checking my plugs and I know my car is rich.....It's fine as long as it doesn't happen all the time...

 

yup.... plumpzz is correct..... if the backfire goes to the exhaust valves and it also happens that your valve springs are not strong enough to hold the pulse... your valves will be forced to open and possible bend themselves by touching the pistons (when pistons are on their way up).... It happened to me when I bent my exhaust valve...

cheers,

richie

 

A little backfire on decel at higher RPM is nothing to worry about. Backfire while at WOT, regardless of RPM, is something to worry about. As mentioned, check the plugs, coil packs, etc. Most backfires result from a sudden lean condition, such as letting off the throttle after a WOT run. Do you have a wideband that you can monitor while the backfire is occuring?

 

I do, but when I'm running wide open on the street, it's hard to look over and see what the A/F is doing; if anything, I'm glancing down at the tach so I don't hit the rev limiter since it gets up there so fast

That, plus the fact that it doesn't do it ALL the time...

 

here is a video of me racing a modded mach 1 stang, car was tuned by cpracing a while back. 400 hp and 342 tq, the TA i raced 2nd was HIGHLY TUNED , i beat him on the 2nd run but never get to pass him in the first race, you can see me backfiring in the first race i believe.

www.panhandlez.com/videos/thursracing.wmv