Question

I mentioned a car backfiring the other day, but I just realized I’ve never actually heard a car backfire before. Is that an actual thing modern cars do or is that just something from TV?

36 Comments

  1. In the old days (when I started driving) you could deliberately back fire by turning off the ignition while driving and then turning it back on.

    Turning off the ignition would allow unburnt gas to pass through to the exhaust system. When you turned it back on the gas would fire with a loud bang.

    This doesn’t happen these days as the fuel pumps are electrical and stop pumping when the ignition is off. Also injected cars don’t have a cup of gasoline sitting on top of the manifold just waiting to drop into the cylinders.

  2. A poorly timed engine or bad ignition parts could cause the same effect unintentionally.

    Intentional or unintentional backfires would eventually blow out your muffler and was generally not a good thing to do to your car as it applies little explosions to parts not desgned for them.

  3. The on/off comment above, and the fuel injection comment, has it just about right. There are many uses for backfiring, including the startlement of innocent pedestrians and (especially) bicyclists.

    25 years ago, when I cycled everywhere, I had cars purposefully backfire at me. Scary. Not as scary as the semi-empty beer bottles and cans, nor as bad as the piece of 2×4 that came out of a car just as it passed by (a complete accident, I am sure).

    I have seen a blackpowder revolver “backfire” in that multiple charges went off when the trigger was pulled. I have seen a camp stove backfire, as the fuel decided it really, really wanted out of the container all at once. I have seen a horse backfire (yuk).

    And I had a truck that dieseled after shutdown, which isn’t quite the same thing.

  4. Once auto companys went from carburators to fuel injection the problems of back fire were almost a non issue. Modern cars can back fire however if the engine managment system is out of wack or if there is other mechanical problems. Carburated cars (almost all pre 1980’s) could back fire for many reasons. Some of the most common reasons are improper airfuel mixtuare and improper ignition timing and advance. Most of us old school hot rodder types prefere carburators over fuel injection. The stuff is just easier to work on.

  5. Wouldn’t the cat convertor prevent a backfire on modern cars? BTW fuel pumps will keep pumping with the ignition off. I found this out the hard way one day when I was replacing a fuel filter. Got it half off, got distracted and had a puddle of gas on the floor after a bit. 😛

  6. There are actually two types of backfire. The less-known type backfires through the fuel system and is much quieter. It is frequently the result of a bad spark-plug wire, and, unlike the one through the exhaust system, can still happen. I remember fixing one of those for an asshole room-mate of mine (he was a law student, which goes a long way towards explaining the asshole part) back in 1973.

  7. i WISH my car could backfire, everybody thinks its a joke, but i would love to scare the piss out of these punkasses around here, particularly the ones in the shiny neon cars blaring rap music.

    that rap music caused me to upgrade my speakers so i could out blare them with Elvis, BOW TO THE KING!

  8. I own a 1994 Toyota Corolla and it will sometimes make a noise like a backfire. I don’t know what the problem is and it may not be a true backfire but it still sounds like it.

    Makes the neighbor’s cat jump into the tree. Also, I once got a group of 5 little kids to run crying to their mothers. Stupid kids.

  9. My riding lawn mower used to backfire on me when I’d shut it off and the air temperature was over 90.

    These days, just my vacuum cleaners blow up on me. I’m no use. (Does it actually help to replace the bag?)

  10. A good backfire is startlingly loud. I let my college roommate drive my ’69 Camaro. Once. He hadn’t even made it out the driveway when BLAM! It had dual exhaust and the muffler on the driver’s side was split like when you put an M-80 in a pop can. The passenger side was unharmed.

    It would do a nice ignition on-off-on backfire and I always wanted to do it when I was passing a cop writing a ticket. Never had the guts. Now I have a stupid little fuel-injected family car that won’t backfire. I can fart louder than that gutless little @#$%^.

    >>>Also injected cars don’t have a cup of gasoline sitting on top of the manifold just waiting to drop into the cylinders.

    Also known as a FIRE HAZARD if you’re a stupid teenager like I was the first time I tried to set the float level and was turning the screw the wrong way. Gas came out the bowl vent – looked like an effin’ drinking fountain. Then it backfired up through the carb and, well, ya know… Surprisingly the only damage was my oh-so-cool see-through fuel filter got a little melted. Those were the days.

  11. Cars backfired back in the day when men without computers could still work on them. I remember my Dad would work on our cars and it wouldn’t take long for him to go into CRM (Car Repair Mode). Women know what CRM is. That’s when a man gets disgusted and swears at you if you offer to help and he asks you for a 1/2″ torque screwdriver dremel hammer (or whatever) over in that toolbox (there are three toolboxes over there) NOW! and you can’t put your hands on it immediately and slap it into his hand with the precision of a nurse in an operating room. The CRM is exacerbated when he scrapes his knuckles and starts bleeding. That’s when you turn tail and run out of the garage as fast as you can. Young women learn all sorts of new swear words if they are around a man in CRM. Adult women know better than to go near a man who is about to perform any task that will put him in CRM in the first place. This includes plumbing or any other home repairs.

  12. #17, Tommy the Towelhead says:

    Any car can backfire if you install a spark plug in the exhaust pipe, a couple of feet in from the tailpipe, and wire it to a coil and an under-dash switch.

    Ha! My uncle had some buddies in high school who did that.

  13. My 73 Opel Manta would backfire until I drug the exhaust system off from the manifold back running a motor rout for a local news paper. Ah the good old days back when cars were cars and news papers REPORTED the news..

  14. I had a 1978 Toyota Celica that would backfire consistenly upon changing gears (choke was sticking open). One day, when driving to church, I shifted from 2nd to 3rd & was surprised at no “bang” from a backfire…

    I thought it was great until I shifted from 3rd to 4th & the resulting backfire tore apart the aging muffler – right as I was passing a local Baptist church in the middle of their service.

    If my timing was right, the preacher could have really gotten his sermon to sink in!

  15. Those were the days! Men were men and carburetors were graded by number of barrels. Take it from me, nothing backfires better than a quick down shift with a 4 bbl carb, it will give you multiple backfires in quick succession, very cool, hard on mufflers.

  16. A backfire, by definition, means an explosion in the intake system. Backfires can be exciting in big block V8s with big carburaters. I once blew the air cleaner off of my ’69 Mercury, when the timing slipped a notch. Seeing flames shoot out of the air cleaner snorkel will chase you out of the garage.

  17. 1976 Alfa Romeo with Spica mechanical fuel injection and mechanical Marelli distributor. Setting timing advance with an impulse-powered (connects in place of plug wire) timing light. Leaning in to get a look at reference mark on front pulley. Battery discharged, therefore voltage regulator calling for full-charge mode. Turned distributor to extreme advance (race car).

    Spark from timing light ignited hydrogen from battery, foomp. Blew my face and eyes full of battery acid. Damn near lost an eye. Then, came back to car 3 weeks later and it would not start. Finally talked to right guy (yes, Italian accent). Little piece of exploded battery case had passed between injector pump belt and its toothed pulley, putting injectors out of time, so no fuel charge when spark was present. Easy to fix, once bandage is off eye.

    So, backfire, yeah. Can be done.

  18. I’m still stuck on the part where you say you’d never heard a car backfire before. Weren’t raised in the South, were you? I was raised in Alabama/Georgia, and assumed all cars pretty much backfired. LOL. Funny, though, I don’t remember hearing that in a long time. Of course, that is probably against covenant rules in this gated prison, uhm, I mean gated snotty community I live in. Someone would phone the gate guards and they would come and shoot the car, and owner, I would think. No disturbing the old farts out at the 9th hole!

  19. mainly cars with points ignition and carburators. Not so much with Fuelie and electronic ignition.
    My ’68 tunnel port Mustang was vicious when timing was off even a hair.
    Get off the gas hard and down shift and it sounded like you were emptying the clip on a .45.
    Beautifull…

  20. Get off the gas hard and down shift and it sounded like you were emptying the clip on a .45.

    Remove the cats off your new car and put a turbo, flowmaster or glasspack on it and it will do the same thing.

    I had my modern(ish) mustang EFI and Electronic Ignition backfire the other day when I had a vacuum leak and loaded it up. I would still rather have an old car. Points ftw.

  21. I had a 1976 Buick Regal that I could make backfire at will. It had a loose timing chain, so if I accelerated up behind some hippie on the freeway and let off the gas real quick, BAM!

    I never had a problem passing on the freeway.

    I miss that car.

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