Backfire

Discussion in 'SN95 4.6L Mustang Tech' started by JamesD87, Mar 15, 2014.


  1. JamesD87

    JamesD87 Member

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    So I think I have a new problem or my old problem is getting worse. So I bought the car roughly a month ago and since I have owned it when you first start it it will die immediately and backfire. It sounds more like a pop coming out of the exhaust. I think I have it narrowed down to the camshaft position sensor and the alternator (I already ordered the camshaft position sensor and am saving up for the alternator). Well tonight, I got in the car and it started fine on the first try (not completely unusual as it was about 50/50 before). So I backed out of my parking space and started to go and after about 20 yards of driving the car died and backfired EXTREMELY loud. Like it sounded like a straight up gunshot. The car started right back up and drove away fine I just thought that was weird. Also, when I am "cruising" there is a hesitation almost as if I take my foot completely off the gas and then put it back on real fast. I know I need to replace the pcv vacuum line but hadn't noticed this symptom before a couple days ago. Could this all be a result of the camshaft position sensor and alternator or does it sound like there is something else going on here?

    A few details, its a 2000 gt with the 4.6 and a 5 speed manual. Im not really sure what is stock and what is not under the hood because im a complete mustang noob. I am pretty mechanically inclined, I built myself a pretty decent jeep but in my mind that's a whole different beast.

    My plan was to replace the camshaft position sensor, alternator, and maybe do some new plugs and wires (any brand suggestions are greatly appreciated). Does this sound like a good place to start?

    Thanks for all your help,
    James
  2. 96juicedgt

    96juicedgt New Member

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    hey let me know what you figure out my car does the exact same thing and my alternator is also pretty well shot still charges but every once and awhile the battery light will come on then once i rev the car will go off i work at auto zone and we have tested the alternator and it passes every time but it also has a whine the only other thing wrong with my car is someone cut the wires to the rear o2 sensors and my car it totally stock as of right now down to the stock air filter let me know what you figure out
  3. D3VST8R96GT

    D3VST8R96GT Member

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    yours sounds like a bad ground
  4. D3VST8R96GT

    D3VST8R96GT Member

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    Get your alternator tested... .no need to spend extra money....

    Any CEL? How are your fluid levels?
    Plugs are a good start check the gap and don't go cheap.

    You shouldn't have plug wires.

    To me it sounds like your timing is off... .bad tensioner or sensor.
  5. JamesD87

    JamesD87 Member

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    What plugs would you recommend?
  6. D3VST8R96GT

    D3VST8R96GT Member

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    Platinums.... not auto lite
  7. JamesD87

    JamesD87 Member

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    I have read that platinums will last longer but don't get as hot do they don't burn the fuel as efficiently as a copper plug doors
  8. D3VST8R96GT

    D3VST8R96GT Member

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    Spark plug material isn't as important in mostly stock motor. As long as you have a good gap youre good. I recommend platinums for longevity
  9. JamesD87

    JamesD87 Member

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    I had no CEL because I have x pipes with no cats. I found an alternator online for $85 (new) with no core charge so I went ahead and bought that a few days ago. It came yesterday and I put it on this morning. So far my backfiring problem has been resolved. I have gone out and started it roughly 5 or 6 times and it hasn't acted up once. Juiced...my battery light would also come on when I got to around 3k rpms and now that is gone also. I will give you guys an update after a few days to let you know if the problem is really solved or if today has just been a lucky day.
  10. 89lxsport50

    89lxsport50 Member

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    I had a similar problem years ago with the original alternator. Most of the time it would start and run fine. About once a day It would start, pop real loud from the exhaust, and immediately die. At first I thought fuel pump. That's what my fox body did when the pump went bad. I did some research online and found someone that said it could be the alternator. I had mine tested, and they said it was fine. i replaced it anyway, and sure enough that fixed it. The alt charged just fine but something in it went bad. I still keep it in the garage as a spare.
  11. JamesD87

    JamesD87 Member

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    Yea my old one was charging just fine also...but it's been 5 days since I put in the new one and I haven't had 1 backfire or problem like I did before...I'm with you, some part of that old alternator went bad...

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