lilrobo

hey guys we still got a mis we think ,, we changed the cop on #6 and #8 and changed all the plugs and the stat to a 195 like it called for ,, what else can we do ? is it possible to have a mis in the elect plug on top of the cop ? what else do we need to check for before we take it back in ??

lilrobo

anyone ????

lilrobo

come on guys no takers on this ,,,, in know some of you guys have had this trouble ??

Derf00

Any of the plugs have oil on them or very heavy carbon build up? A leak or a cylinder running lean/rich could cause a misfire.

What made you change the coil on #6 and #8?

lilrobo

no the old plugs looked good really thats what throughing us for a loop nothing looked bad now some of the cop felt hot when we took them out

Derf00

Is it a miss at idle or at a certain RPM?

Stock air intake or aftermarket?

lilrobo

well at a idel i guess stock intake

Derf00

You've done the plugs - those looked clean - rules out oil contamination or lean/rich conditions
You've done two coils - #6 an #8 (but just getting warm/hot is not necessarily a reason to change them)

Fuel filter, fuel system cleaner, test the coils themselves or the wiring going to them to see if the signal or coil is weak.

Those are the next few things i'd try. For the coil and and the wiring, I know it can be tested but I don't have that info handy. Google for Testing Coil-on-plug or Testing Mustang Coils should get you what you need.

lilrobo

OK thats what i think too we need to check the cop plugs and wiring on the interstate in gets great mileage but town its terrible

Derf00

okay here's a very basic one..Air filter....
If you are using one of those oiler type air filters you may also want to take a look at the screen behind the air cleaner housing and see if it's got gunk on it. Even a little bit will affect the car at idle.

Did this misfire just start?