Spark plugs and lack of power

[Davidw04]

What are the best plugs for an almost stock Mach. All I have is an intake, off road x pipe and weld in mufflers and an sct tuner. My car feels like it lagging in the mid and upper range. I’m replacing my fuel filter this week and was thinking about going back to the motorcraft plugs from the ngk v-power plugs that I have in it now. Car smells really rich which the fuel smell is normal without cats but I think this is a little excessive to where it burns your eyes and your clothes smell of fuel. And occasional puff of grey smoke on startup. Pretty sure it’s not oil and that it is fuel which could also be an injector. What do you guys think?

[j rick kirby]

I think your car stinks because of not having any cats and the puff at start up is usually caused by a little oil that has puddled in the intake after having been drawn in thru the PCV system. I use the regular copper NGK TR6 and they work just fine. Unless you have a cracked or broken plug or they are completely worn out you probably won't notice any driveability difference by changing them. If your plugs, and filters are good and you really are feeling a lack of power then your problem is likely one or more coils that are weak. A fresh set of coils on my 150,000 mile motor that was fish biting really woke it up and it feels new again. Coils can work fine when cold but as they warm up and the components expand then sometimes a gap will occur in the windings and they fail to function properly.

[ab_mach1]

Originally Posted by j rick kirby

I think your car stinks because of not having any cats and the puff at start up is usually caused by a little oil that has puddled in the intake after having been drawn in thru the PCV system. I use the regular copper NGK TR6 and they work just fine. Unless you have a cracked or broken plug or they are completely worn out you probably won't notice any driveability difference by changing them. If your plugs, and filters are good and you really are feeling a lack of power then your problem is likely one or more coils that are weak. A fresh set of coils on my 150,000 mile motor that was fish biting really woke it up and it feels new again. Coils can work fine when cold but as they warm up and the components expand then sometimes a gap will occur in the windings and they fail to function properly.

Also, the stock tune ford put on these is pretty rich. At least mine was. I’m not sure if there was any difference between 03 and 04.

[j rick kirby]

A number of tuners have told me there's not much power to be had from tuning a basically stock engine so that tells you that the factory tune is pretty good. Now you can always lean it out some more and maybe bump the timing a little but that's how you screw up a motor and get very little for it. A little on the rich side is safe. I track my car so that means that I am turning it hard for extended periods of time so I use a plug one step colder to lower plug temps and give me a little safety margin against pre-ignition.

[LXS]

I’ve been using NGK Iridium ix for the past 10 years or so, haven’t had a problem so far

[Davidw04]

My car only has 56k miles on it so it does sit a lot. And I am running a Bama tune I gotta try to datalog it to see if that shows anything.

[j rick kirby]

You guys who have cars that sit a lot please be careful. The alcohol in the fuel will ruin your fuel system due to its hydroscopic nature. Keep Stabil or something in it. Many a fuel pump has been replaced because the moisture killed it.

[rich1]

Originally Posted by Davidw04

My car only has 56k miles on it so it does sit a lot. And I am running a Bama tune I gotta try to datalog it to see if that shows anything.

If its a Bama tune that is most likely the problem. There has been a lot of talk of the race tune being fueled too aggressive for the street.
I run NGK TR6 plugs ..the fine wire plugs run too hot and are for EPA lean burn