Can an Automatic backfire???
10-27-2005
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Can an Automatic backfire???
ok so last nite i was on the 101 heading to hollywood, i just installed a new muffler (thanks 2 yourinmyw0rld) anyways, it was a used muffler by the way, i've had it installed since sunday, and i've brought my car up to 60mph already, but last nite i was on the freeway right? i was doing about 80, and i doubled peddeled the gas so my rpms would go down, and i heard a POP! at first i was thinking it was my tire, but my car didnt shake or nothing, and it kinda came out from the exhaust, or so it sounded like? so was that a backfire???? call me a noob if i think this*, and how does a backfire actually happen???
10-28-2005
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nooo, that happend to turbo cars. my 05 ex does it now and then. when i downshift or free rev it will backfire once in a while. sounds like a thump on the floor. i know the noise youre talkin about. my cars pretty heavily modded besides what it says in my profile. its not turbo or nething tho. what makes it make this noise??
10-28-2005
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Rep Power: 259 It doesn't just happen to turboed cars. There are two main things that can cause this condition. First is a low fuel pressure condition. Full fuel pressure is needed under load, check fuel pressure under load it should stay between 35-45 pounds if not replace the fuel pump. Second is the ignition system. If the ignition system is worn it can misfire causing the backfire you describe. Check your spark plugs and ignition coils, replace as needed.
10-28-2005
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"mmmBAHHHH" - vtec y0
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my car makes poppin noises from the exhaust mainly when i let off the gas and let the revs fall itll go pop pop pop pop pop pop pop it sounds cool and everynow and then i can get a loud pop when i let off the gas inbetween shifts
10-29-2005
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Rep Power: 232 if ur using a MT car, i think it would happen when u downshift, and lift the clutch a bit so that it slows u down, and i guess it also depends on ur exhaust, i have a tanabe style exhaust, real deep tone
10-29-2005
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Originally Posted by White0nGold
if ur using a MT car, i think it would happen when u downshift, and lift the clutch a bit so that it slows u down, and i guess it also depends on ur exhaust, i have a tanabe style exhaust, real deep tone
10-29-2005
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Rep Power: 0 I believe a backfire is caused when excess fuel enters the exhaust system and ignites, thus causing the bang. A misfire in a cylinder could cause the unburnt fuel/air mixture to be expelled from the cylinder and once it reaches the exhaust system, the heat causes it to ignite. Often when cars are very poorly tuned and are running excessivly rich you get a lot of backfires because not all of the fuel is burning in the cylinder. I've also heard that for some racing applications backfires are purposely induced to keep turbos spooled up. I could be wrong though....
10-29-2005
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You gotta be as blind as Anne Frank not to see that
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Rep Power: 0 on my bike, r6, it always goes pop pop pop when i downshift at higher speeds and use the engine to slow the bike down..i have a slip on so i think it def depends on the exhaust
10-29-2005
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Originally Posted by White0nGold
so does urs go pop pop pop pop pop pop?
10-29-2005
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Rep Power: 0 stupid question. is there any reason to tune my car?? its an 05, but its modded a bit. i really do not know how its running, its pretty quick. think my local shop with a dyno will tune it?? i really dont know that much about tuning?? any suggestions?
10-30-2005
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Rep Power: 787 first you need something to tune with. I had a vafc to adjust air/fuel, but took it out. It didn't really help at all.
10-30-2005
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Rep Power: 787 ya i do actually. someone was gonna buy it last week but I haven't heard back. It works and all, but with my mods they all cancelled the stock richness and the a/f is pretty good by itself. Comes with everything even box and instructions. (Will include correct instructions from an old post on 7thgen). How about $250 shipped?
10-30-2005
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Rep Power: 787 no its mostly for na actually. boost you want something better like aem ems or emanage. it stands for vtec control air flow converter. It lets you adjust at what rpm the vtec shifts to hi cam and also lets you add or subtract fuel at 100rpm increments. So if you're running lean with your mods, you add fuel and make more power. everything is best done on the dyno so you can see what settings give more hp. It also monitors alot of engine functions, like voltage, rpm, throttle position, correction, and more. and it has a vtec light that goes from green to red when vtec kicks in.
10-30-2005
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Touch it... He won't bite, He'll just come at you pretty quick.
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Originally Posted by 05civicexse
nooo, that happend to turbo cars. my 05 ex does it now and then. when i downshift or free rev it will backfire once in a while. sounds like a thump on the floor. i know the noise youre talkin about. my cars pretty heavily modded besides what it says in my profile. its not turbo or nething tho. what makes it make this noise??
AEM CAI, Magnaflow Cat-Back, Megan racing downpipe, Vortex Throttle body spacer, Ported and polished throttle body, race header.
You can that heavily modded?!?! LOL!
You need to step away from 7th gen civics my friend. 
10-30-2005
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10-30-2005
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Rep Power: 787 its just an add-on computer. it changes the air/fuel ratio. Normally most cars run rich (too much gas and too little air). This is better for emissions I think but not for power or engine operation. You want an ideal ratio of 14.7:1 and thats what you tune on the dyno by adding or removing fuel. Most members who tune IHE mods with a manual civic get around 10whp.
10-30-2005
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Rep Power: 341 pretty sure most cars do backfire a little, or at least pop. ever hear a car that's straight headers? used to have an old 88 or 89 prelude in auto shop, took the exhaust off one day and it sounded meaner than a harley, with lots of pops and such. just about any car without mufflers/cat will pop and backfire. the muffler does just that, and muffles the loud pops and of course the exhaust noise. that may, at least, play a small part.
