CJ043Pt9Pony

Does anyone know the exact or best gap to set Autolite Double Platinum plugs for a 2004 3.9L (V6) 238ci. The Hood says i think .051 or .052-.057, Im thinking its .054! Im putting new MSD 8.5 Wires in and ripping out motorcrafts crappy factory 1's. If someone could let me know what i should set them to so theres no problem with fouling, carbon...etc, let me know!

Thanks,
J

UTI_TECH429

gap has nothing to do with cabon or fouling. but follow the spec thats on the hood

67mustang302

Actually it can, but to a small degree. Larger gaps generate more heat at the point of firing and can reduce deposit buildup right at the electrodes, but require more voltage to jump the higher resistance gap and can erode the plugs faster. Heat range will have the biggest effect on deposit buildup in a properly tuned engine though. Moderate to heavy fouling is usually the result of either too weak of an ignition, too much fuel or burning oil. Sometimes it can be bad gas too.

Just gap it to stock and it'll be fine, give or take 5 thousands(or more even) on that engine prolly won't even be noticeable. You need enough gap to generate the heat required to ignite the mixture, but not so much that the cylinder pressure tries to blow the flame kernel out before it can generate proper ignition. If your engine is mostly stock, it doesn't have nearly the cylinder pressure to create blow out at larger gaps, and will still ignite the mixture with a smaller gap. It's just not that sensitive to plug gap to matter whether it's in the high or low end of the factory range. Unless you go excessively large or small it prolly won't matter.

Have you been getting fouled plugs? If so and it's not right on the electrode, it's most likely something else causing it. You need to find out what that is and fix it, not just throw random parts at it.

UTI_TECH429

sry my dumbass friend was on here and he knows nothing, yeah but like he said if it were mine i would go about 1 or 2000 over the spec and you will be fine, i believe the spec is in your owners manual to so check there sry for the confusion