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Discussion Starter #1
I have a 2000 v6 mustang. all was good until i replaced the plugs and wires and now It is backfiring. I tested it by pulling each wire to see which one does not effect the idle and narrowed it down to one. I have tested to ensure I am getting spark at the plug and I do.I even replaced the plug thinking I may have got a dud. Any thing else i could try to get this fixed without a shop?
 

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Back firing is unburnt fuel in the exhaust. This is usually due to misfire. Or it can be timing related.

So, since it ran fine before it was "fixed", let's go back and check a few things.

Did you route the spark plug wires using factory looms and standoffs? Are the plug wires touching any metal parts?

Since incorrect timing can cause backfires, how does this relate to your problem? Are you postive that the wires are correct at the coil pack? A mistake here and you would see a spark but it's at the wrong time. FWIIW, if asked to handicap this thread, this is what I would vote.
 

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Back firing is unburnt fuel in the exhaust. This is usually due to misfire. Or it can be timing related.

So, since it ran fine before it was "fixed", let's go back and check a few things.

Did you route the spark plug wires using factory looms and standoffs? Are the plug wires touching any metal parts?

Since incorrect timing can cause backfires, how does this relate to your problem? Are you postive that the wires are correct at the coil pack? A mistake here and you would see a spark but it's at the wrong time. FWIIW, if asked to handicap this thread, this is what I would vote.
You crack me up, dude.
 

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Is it too much?
 

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Discussion Starter #6
By bad on the wrong thread.. When I replaced the wires I did one at a time to ensure I did not mix them up and even double checked it with Ford's diagram. The old plastic holders broke when we took them off but we replaced them with aftermarket so the wires are not touching any metal. We ran the car at 1100rpm and removed one wire at a time (to see which one caused the car to run worse) from the coil and identified that it's number 5 that is the problem child. We replaced just that one wire also with no luck.
 

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Discussion Starter #7
Back firing is unburnt fuel in the exhaust. This is usually due to misfire. Or it can be timing related.

So, since it ran fine before it was "fixed", let's go back and check a few things.

Did you route the spark plug wires using factory looms and standoffs? Are the plug wires touching any metal parts?

Since incorrect timing can cause backfires, how does this relate to your problem? Are you postive that the wires are correct at the coil pack? A mistake here and you would see a spark but it's at the wrong time. FWIIW, if asked to handicap this thread, this is what I would vote.

By bad on the wrong thread.. When I replaced the wires I did one at a time to ensure I did not mix them up and even double checked it with Ford's diagram. The old plastic holders broke when we took them off but we replaced them with aftermarket so the wires are not touching any metal. We ran the car at 1100rpm and removed one wire at a time (to see which one caused the car to run worse) from the coil and identified that it's number 5 that is the problem child. We replaced just that one wire also with no luck.
 

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Looking at the Ford service manual, some other things to check.

Secondary ignition (#1!!!)
Excessive oil use.
Fuel pressure
Dirty/clogged/stuck open fuel injectors.
dirty MAF. Use only product designed for the job.
Exhaust leaks.
Exhaust blocked.
Vacuum leak or PCV system leak.
Base engine problem (valves/rings/compression).

Try this old racer's trick. Run the motor in a totally dark location. Look for the blue hue of escaping spark. Look for white spots which also indicate arching.
 
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