my 82 rx7 sounds like its back firing when starting to rev and as the rpm goes down. it makes a popong noise is this a sign of my engine running rich ? any suggestions.

 

my 84 does that and I thought it was because it needs a new muffler.

 

You'll know when I rotory backfires......sounds like a cannon!!!!!!! Check the timing and/or carb maybe running too rich.

 

you must have a leak in the exhaust somewhere... i had that same problem when i had a leak. i fixed it a month ago and it hasnt backfired since..

 

Yep, my money's on an exhaust leak.

 

ahh its a rotary.,. get use to it..

 

well before i bought the car the previous owner if i remember said it was runing rich . i dont know how to mess with the carb that well and from what ive heard its pretty hard . i also had a new cat and muffler installed in the car like a month ago , im planing on bringing it to the shop and see what the can do with it .

 

Yeh, kinda get use to it / or a exhaust leak.

The engines burn a lot of unused fuel.. so when reaching high rpm then backing off, you are def gonna hear it more often than not.

 

Hmmm, mine hasn't backfired in quite some time. Now that you mention it, I sorta miss it.

Matter of fact, it stopped when I fixed my grinding noise (RD). Try playing with your timing.

 

Since when did this turn into a "bad thing"? Doesn't this make you cool? lmao...

 

Only if you have flames shooting out at the same time

 

Is the stock exhaust system intacked or have the Cats been removed or Altered in any way?

I have a wide open exhaust system with the RB Headder and presilencers and that **** is loud, and it back fires when I down shift because there is no where for the unburned fuel to go so it detinates in the exhaust pipe.

If the stock exhaust system is intacked my moeny is on the exhaust leak...

Good Luck

A

 

Timing is another excellent possibility (good call Jay). Check it out, better gas mileage, more power, less backfiring with a well timed engine.

 

the cat is brand new, i will check timing when i have chance hopefully not off.

 

How do you check timing and where exacly do you look to tweak your carb for better timing?

By the way I have backfire but I know for a fact that my Cat is cracked so it leaks right from there.

 

The timing has to do with ignition, not the carb. To time your car you need a timing light. After that, just follow the directions in the manual.