I have an '87 rx7 superbase model, it is 5speed. When I shift @ 4,000 rpm it back fires, and if I am getting on the gas pedal it back fires really loud. My car is running richright now, so my question is, because I am running rich is that why I back fire, or could it be my cat? The car doesn't do it all the time, just sometimes, the plugs are good, I just changed them about 1 month ago, so I know it is not that. Does anyone have any ideas. Any ideas would be appreciated. Oh one more question, if I cut out all my cats and pre-cats, would I get backfire from my car?
Just curious.

 

Could be the timing. Could be that the anti afterburn feature of the acv is not working. The acv, when it senses deceleration or a closed throttle, injects air into the intake manifold to prevent backfiring. Thats the one and only time the acv injects air into the intake manifold.

 

I just had my cat cut off and replaced with a straight pipe, and my backfire is worse. I need a major timing adjustment, you might need the same.

 

I thought that all rotaries would "backfire" with a open exhaust. I know mine did it when I had holes all through it. Whenever I shifted at high rpm there was a "pop", and when decelerating while in gear it would pop alot also. Now that I have a all new exhaust it doesnt do it anymore. Well at least I cant hear it anymore anyway.

 

808's backfire issue is pretty bad someone help this poor soul out with some good info. Any ideas anyone?

 

aside from finding a way to lean out the mixture a bit, i would suggest the exact same things as hailers suggested. check the timing, it may be too advanced. if that's not it, then see if the acv is functioning properly, it's in essence leaning out the mixture a bit ...

808burn~
if the backfire-thing is driving you THAT crazy, then you definitely DO NOT want to take out your cats and pre-cats!

good luck

 

Both of my rex's backfire -- Make sure if you changed any part of the exhaust that all the bolts are on tight... A little leak WILL cause the backfire.

I used to be annoyed with the backfire but im not anymore -- go to mazdatrix page and listen to their "tester" model; they installed a RB catback -- it backfires like crazy...

So im not worried anymore...

 

Basic bullshit. I've got a full open exaust on a 82, 87n/a and a 87TurboII. There is no backfire. Its Racing Beat header and Racing Beat presilencer and Racing Beat catback on the 82 and the 87N/A. Sounds more like a poorly tuned car to me. Not humor.

 

I drove a modded NA today (RB header and straightpipe dual exhuast). I didn't back fire, but it did shoot flames. I was told that at one point I shot 2ft flames outa both mufflers. hehe

 

I prefer to call it Afterburn.

My 87 NA used to do it sporadically, and not very loud. At the Ottawa meet this past Spring, at one point I was sitting and revving up around 6.5-7k and each time I let off the gas she would POP.

Then I threw on a downpipe and hi-flow cat and the Afterburn disappeared for almost 2 weeks. Then it came back. It only happens when I downshift, most often 3rd to 2nd, and also when I do the above-mentioned revving.

The bonehead at Midas who put the pipes in didn't RTV the gaskets, so I'm hoping that that will help reduce it when I get around to it. It's nice that my 7 is a head-turner, but I'd rather it was because she's so pretty and not because people think they're being shot at.

 

I have no cat, no EGR, no ACV on my 88 tii. And it backfires like ****. eh, you'll get used to it.

 

yes check for leaks, I fixed my leak and no more backfiring, just flames

 

is it bad for your car if it afterburn (backfire)
cause my does it crazy too
i got new high flow cat and new mufflers

 

Everything I've read says that Afterburn is both normal and harmless.

 

ok, so it could be leaking exhaust, bad acv, or eventiming. So these are the things I need to check. I think it might be the leaking exhaust, becuase I need a new cat, and I checked it out, and replaced the gaskets, but they were worn, and I can smell the exhaust and gas at the middle of the car, so I know it is leaking some where around there. I will check all of this out and go from there, thanks. Oh by the way Amur_ what is RTV the gaskets, pardon my stupidity. I have never heard of this before. Thanks again guys. Oh, and thanks knight1976 for letting everyone know that my car sounds like complete ***.lol Lates

 

Silicone sealant. High-temp stuff. Available everywhere, and it's cheap.

What stupidity? It wasn't so long ago that all of this was Greek to me, too.