bad misfire / stumble

[9646gt]

Well I have had my 96 gt for about two weeks now..since i bought it I have had a problem with stumble at moderate to heavy throttle...the only know problem was a CEL error saying the cats were stopped up ..but those have been removed is the reason its on...I changed the plugs (autolite platinum) with NGK platinums in the stock heat range..the car had never run better ...now a tank and a half later it is back..I changed the fuel filter and it is still acting up...is there a good chance a set of autolite 764 coppers will fix this problem? I have heard the 4.6l doesnt like platinum plugs and is really picky..and it makes sense that copper conducts electricity better...I just need some opinions BC I am going to change the plugs yet again tmrw seeing as how they may have fouled out...if you guys can help in any way b4 I hit the parts store tmrw I would appreciate it! Thanks alot and its nice to own a Stang again (when it runs well heh)

 

[MustangSally98]

I had the same problem when I changed my plugs and wires in my 98 gt. I wish I had done the research cuz i did put the platinums on but oh well, she's on her way out...but my problem came from wire #8 was not all the way in. This caused a bogging under heavy acceleration. Double check your wires.

 

[9646gt]

I appreciate your response...I went out today and bought some Autolite 764 copper plugs..going to install them right after work and see if they hold up...if so platinum plugs will never touch my baby again lol..thanx for the suggestion and I will check the wires

 

[COramprat]

I agree with checking the wires...maybe even replace them. One of them could have worked it's way loose or the conductor may be broken. The platnums vs copper really shouldn't be the problem with the stumble.