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  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

miss fire/ sputtering exhaust at idle after spark plug swap

  • Thread starter Thread starter 02red4point6
  • Start date Start date Sep 11, 2011
0

02red4point6

New Member
Mar 30, 2011
26
0
1
Sep 11, 2011
#1
  • Sep 11, 2011
  • #1
ok guys so today i decided to put autolite 762's in my car. install went rather easy and it was pretty straight forward...UNTIL i went to start up my car. when i started it up, it made this bubbling/sputtering noise from the exhaust and smelled a tad gassy.

when putting two of the COP's back on, they didn't click much when connecting with the plug. i just pushed it in and tried to push it down all the way in to try to hear a click and it didn't click much if at all. i also noticed that they werent connected very well with the plug, meaning when i tried to take the COP off after pushing it in and wrestling with it, it sort of came off extremely easily and i didn't have to use the force to take it off like i did taking them off the old plugs. ALSO, on one or two of the plugs, when pulling the cop's off, the plastic part disconnected from the rubber boot, leaving the spring exposed.

other than that, i really don't know what else i could have possibly done wrong. all torqued to spec, .054 gap (one or two might be a TAD...TEENY bit more, but i'm pretty sure they're all the same).

before the install, the car was running very smooth, strong, and didn't make these pronounced bubbling, sputtering noises. 91 octane sct tune was on the car before, during and after install. i switched it to the 93 just to see if it did the same sputtering, and it's still on there right now, and still sputtering.

i need suggestions from all of my mustang brothers on this one... i don't think i'm going to sleep much tonight because of this... PLEASE!!!!
 

1987stangman

Member
Jul 12, 2006
684
24
19
Sep 12, 2011
#2
  • Sep 12, 2011
  • #2
Sound like you need to revisit those cops. Has the CEL light came on? Have a scan tool?
 
0

02red4point6

New Member
Mar 30, 2011
26
0
1
Sep 12, 2011
#3
  • Sep 12, 2011
  • #3
i'm revisiting everything. turns out 762's are the wrong plugs. 764's are what i needed. no CEL, i am about to see if my sct tuner can see what's going on, but if not, i'm sure everything is working correctly but the plugs are the wrong size/wrong spark or something...... HOPEFULLY this will work.........
 
0

02red4point6

New Member
Mar 30, 2011
26
0
1
Sep 12, 2011
#4
  • Sep 12, 2011
  • #4
disregard that post, I did in fact put 764's in yesterday.
 
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