I am doing my first tune up on the mustang since i bought it a year ago. I am buying new wires and plugs to start off. Does anyone recomend any specific plugs and wires that will be capable with the performance im putting into it. Im not Super charging the mustang yet, if that helps. I have minor bolts ons.

 

First of all you're not buying wires...


Tr6's are a great plug...

 

yes i was being general i understand i am not buying wires..........sorry about that. I ment i am replacing the coils....does anyone have any suggested brands or types on the coils or spark plugs.

 

Why are you replacing the coils, just to spend money?

 

Yeah, unless a coil goe's bad you don't really need to buy new ones.

 

i am asuming the coils are going bad....i bought the car a year ago and the guy said that he switched out the coils and i dont know if he put in a cheap coil in or not...the car is having trouble turning over.....it does but takes a second. So i figured new battery and plugs and wires might do the trick.

 

Does the engine run rough or skip under load? If not then there's nothing wrong with the COPs and all you probably need is plugs, it is under load that the spark plugs need the most voltage to ionise the gap.

Also, there are no "wires" so you need to stop thinking that way (see below). The closest thing to a wire is the stainless steel spring that connects the COP output to the plug. These are quite robust and not likely to ever fail electrically.



The boot that insulates the spring can deteriorate and leak/bleed HV into the head, a visual inspection will clearly indicate if this is happening, as will running rough and skipping under load.

If you find that one or more boots have "blown through" they can be replaced for $3 each mail-order, a bit more at your FLAPS.

If you are having starting problems check the battery voltage during cranking, if it's falling much below 11.0V to 11.5V then the battery may be weak and need replacement.

 

Sorry to hi-jack, but "engine run rough or skip under load" is exactly what mine just started doing. Are the coils the culprit? I don't believe the spark plugs have ever been changed either.

 

How many miles on it?

The first thing to do is pull the COPs and test them with an Ohmmeter. The primary coil (the low voltage side, measure across the two terminal where the harness connects) should be 0.3Ω to 0.8Ω on a stock coil. Note that this is a very low value and many/most inexpensive multi meters are not very accurate in that range, so if it's less than 2.0Ω it's probably OK.

The secondary (high voltage) coil, measured between either of the primary pins and the spring or terminal at the bottom of the COP should be between 4.0kΩ and 10.0kΩ (4,000Ω and 10,000Ω). Typical values I have seen are 5.5kΩ to 7.0kΩ.

In may experience the most common failure is a short in the secondary coil which can be identified as a secondary resistance of less than 4.0kΩ--usually a bad secondary will read 1.5kΩ to 2.5kΩ, or open.

If the COPs test OK then yank the plugs and see what you can see, keep track of which cylinder each came from so that if there is a problem you'll at least have a clue as to where to look further.

I'd put new plugs in anyway once I had the COPs and old plugs out...

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After market "high-energy" coils typically have lower primary coil resistance, 0.1Ω to 0.2Ω. This makes them draw more current, which equals more energy, which produces more output voltage when the field collapses--and which causes the secondary windings to fail sooner all other things being equal.

 

Thanks! Miles = 115k.