I recently installed a torqer v2 cam (232/234) @112, BTR dual valve springs and pushrods...it is untuned because my nearest tuner/shop is about 3 hours away and its hard to make time with work and all...

now when i start it up in the mornings it starts up perfect and idles around 1000 then settles down to about 850 once warmed up...it drives stock/normal if i shift around 2600, if I drive like an old lady and shift at 2000 u can feel it hesitate a bit. I usually cruise in 4th going 40 and no bucking/hesitation. I have not been an idiot and gone full throttle to redline, most I ive done is half to 3/4s throttle to about 4000 and only once, i know there is no point in gunning it right now...but here is what puzzles me....

after the car has warmed up, say im just idling at a stop light or at a drive thru, I get a really loud random backfire out the exhaust, sometimes two in a span of 5 seconds...its loud enough to freak people out next to me....soooo is this normal for an untuned car?? Or is somthing wrong??....I know i need to get it tuned, but i dont wanna drive 3 hours for the guy to tell me something is wrong with the car...

here is a video i took at home after about 20 minutes of driving in hot 85* weather in South Texas today....at around 41 and 43seconds the backfires are heard...they sound much louder in person, u can actually feel them...I hope this is normal for an untuned car....mods are haltech intake, lg longtubes, no cats, b&b fusion exhaust, stock ported TB, ngk TR55

http://www.youtube.com/watch?v=BOGuD...ature=youtu.be

 

I think once you get a tune that backfire will disappear, If it was something abnormal it would be doing it alot more often IMO

 

I bet its pig rich and your building up unburned fuel and its causing the POP..

I agree... Once its tuned, it should stop.

Bill

 

I had this happen when I cracked one of my spark plugs. Double check to make sure. Im assuming you pulled them in order to change the cam/springs. Jay

 

Good point! I had a cracked plug also but it only misfired under power. Easy check.

Bill

 

I changed to new tr55 when i did the cam swap, and i just checked them a while ago, nothing unusual.........but maybe after putting about 200 daily driven miles untuned the plugs have become fouled?? but i doubt it, they looked a little greyish and some slight carbon buildup, no oil either and no dic codes.

 

I just changed to TR55's a week or so ago and i had cracked one and it idled fine, it only backfired when I went WOT.

 

You could seperate the exhaust from the headers at the collectors and see what bank is popping.

 

Just needs the tune. I have this cam and it never backfired pre/post tune. Car was not drivable though after the cam swap (surprised you have driven it 200 miles). I had to do some pre-tuning (mostly idle tuning) in the drive way to get it out of the driveway. I would get it tuned before driving it much. Surprised you're not having surging issues (especially when the motors hot).

I have seen one other post for this cam backfiring before tuning.