[cranberry]

When my cooling fan comes on my alternator gauge drops some and my car misses, I have replaced the battery and alternator. I have a 1998 mustang gt 4.6. Can you please help me?

[Casper98GT]

the battery gauge might come down slightly with the a/c, but you probably have a misfire slightly or a vaccum leak and the a/c puts extra strain on the motor. So it intensifys it.

[cranberry]

THANK YOU

[Casper98GT]

Not a problem

[John C]

If U have access to a scan tool, look at cylinder balance and see what cylinder is dropping off. most likely will be a bad plug wire expecially if they are the original ones. I have seen coil packs fail, but only 1 or 2 in my years of servicing ford vehicles.
I hope that this helps, John C

[Casper98GT]

John, when were you a tech ? Just wondering because i repplace coil packs daily, and i have replaced my 2, and my dads 2 coil packs. a coil pack on his old v6 f-150. haha

[John C]

Most of the vehicles that we see in the shop now are using the coil on plug setup ( 1 coil on each spark plug). I haven't seen a coil on a 4.6 stang or truck go bad in quite some time. I have seen a lot of the V-6 coilpacks go bad on rangers and tarus/sables. I have been working on fords alone for about 15 years and have about 25 years of automotive experince. Any part is possible of failing, but that doesn't mean that everyone will experience it. You also have to realize that at 80.00 per hour to get work done most people with a vehicle past 5 years of age will not allways go to a dealer to get work done.

[98StangGT]

how can I test my coil packs if they are bad? cause my car misses alot, exspecially under acceleration, I already replaced plugs only

[wolffer]

my cobra is going down the same road as yours with the missing at higher rpm under load so i am trying the replace all ignition components at once route .I am trying Jegs 4.6 MSD ignition upgrade and hopeing that will fix it. cant wait for fed ex, there is no replies on my power pulsing problem so I will an update after the spark upgrade.

[John C]

Mustang 98
This is a old trick that was learned in an older ford drivability class. Your car is like mine and has the 2 coils, each has 4 wires on it. take some paper clips and cut them in half. remove each plug wire and bend one of the paper clip wires so that it goes down into the tower for the wire and sticks out a little when the wire is reinstalled. Do this with all 8 wires, and make sure that none of them are shorting out to ground. I don't know if your car is a stick or auto, if auto get some one that U trust to get in car and powerbrake it untill the miss starts. Touch each wire one at a time with a grounded test light. The cylinder that is missing will not change when doing this, the others will drop out at this time. I have done this at home before investing in my IDS (7000.00!) and it does work. Most likely if U have the original wires they are the problem, I would change them before spending money on coil packs. If U have a good friend that will let U borrow one, swap yours out 1 at a time and see if the concern corects itself. that will tell U if the coil packs are the cause of your woes.

I hope this helps, John C.

[pooh1992bear]

can you help my mustang is reading a code P0302 cylinder 2 misfire. i am not sure how to use this site. my brother has replaced my fuel filter and we just had a diagnotic ran on the car what should i look at first? how do i read a response?

[John C]

Easy one, swap the coil on plug assy on #2 cylinder with one of the others and see if the miss moves. P0302 means missfire on cylinder #2. If it sets a miss fire code for the cylinder that U move the coil to then the coil is the problem. Start here first.
Hope this helps, John C

[pooh1992bear]

thanks

[Mystry]

98 my car did that too but i replaced not only the plugs but the wires too and my problem is gone

[pooh1992bear]

I am going to try that thanks so much

[pooh1992bear]

mustang gt 4.6 was missing cylinder #2 changed spark plugs when i took the spark plugs out there was oil there. what should i check. i know this is probably a major problem.

[John C]

was the oil down in the hole the plug sits in (on the outside of the plug) or on the inside of the plug as if motor is burning oil? need to know this first.

[pooh1992bear]

the oil was inside where the plug is.

[pooh1992bear]

the car is not smoking or running hot. just found oil on the plug when we pulled it out and also found gunk on the other plugs. all of the plugs on the left hand side when you are facing the car under the hood

[John C]

Ok, somehow oil is getting into the tubes that the spark plugs are in. U can rule out the intake manifold. Most likely coming out of one of the breather hoses or the pcv system or the valve cover is leaking. clean off the top of the motor very well, use spray 9 or something like that. Add some floresent dye to the engine oil and run a couple of miles. Check with a black light and see where its comming from and go from there. U may have to let it run for a good while or drive it a couple of days before U can locate where its coming from. Then U can plan your correction to the problem.
I hope this helps, John C
U can get engine dye at a Napa store, shouldn't be more than 10$