New RX-7 Stud

Hey guys i need help on a backfire problem, it started yesterday when me and my friend swaped my holley carb onto his rx to see if he liked it and when i drove it home and turned her off my car waited about 3 sec then made one loud backfire. I have never heard this before and it made me worried that we screwed up the carb when we were playing. If you have any suggestions on what this might be it would be greatly appreciated. Thanks

Box_Man

That's a problem?

It's just the raw unburnt fuel hitting the cats after you shut the car down. It's still pumping fuel and air, just without spark for a little bit after you turn the key off. It happens, fab up a catless exhaust if you don't like it. Personally, I love setting off car alarms with loud backfires.

New RX-7 Stud

Hey J thanks for the help. I have a 1980 rx with a 12a engine. I took my carb off yesterday put it on my friends rx for like 20 min then switched them back. It runs fine and dident seem any diffrent except for the one single backfire right after that car turns off. It has to be something with the carb because it never happened before. Its confusing because we did everything right and the transaction went smooth but still i ended up with a problem. Thanks for the help if you think you know the prob it would be greatly appreciated.

85 FB

Does your car backfire while you're downshifting and the like while driving?

aussiesmg

iTrader: (1)

Welcome to a modified rotary....lol, it isn't a problem just cool

Box_Man

It's not the carbs fault (well, it sort of is, I'll get to that later), it's the unburnt fuel hitting the hot catyletic converters and combusting in the exhaust. The reason the stock carb does not do this is because there is a little electronic solenoid thing on the stock carb that controls fuel flow. When you turn the key on it opens up and allows fuel to flow into the carb, and when you turn the key off it shuts to keep the fuel flow to a minimum as the engine spools down, preventing flooding and backfiring. Aftermarket carbs do not have this, and it really isn't needed.

firstgen689

hey he is say he had the holley on it first and it did not do it, and the second it was on his friends and then he took it of his friends and put it back on his

New RX-7 Stud

well gentlemen i wrapped my rx around a telephone pole today and fixed my carb problem! Parts anyone?