I remember reading about the heater hose problem over COP #4. Tighten and or replace the heater hose clamps. Also, read about the rain gutter along the back egde of the engine compartment draining in the same area. Good luck!

 

I have a 97 with the 5.4. It lost the number 4 cop due to the heater hose leaking on it. I replaced the hose clamps & the coil & plug. I've had1 more cop fail since then. I may replace all my cops with the ones Troyer performance offers that are higher voltage on my next tuneup.

 

"Higher voltage"...that's a good one.

The coil will only continue generating a stepped-up voltage until the plug fires.

No more, no less.

And a new fine-wire plug will fire at a LOWER voltage than an old, worn out one.

Steve

 

just looking at the plug thing from an electricians point of veiw ( my profession of choice ) if you have more windings on the secondary side of the transformer you will bump up your output voltage ie your higher voltage coil. now the coil will not build electrically for no more than the period of time between o vdc and 12 vdc or the capacitive input amount, because straight dc voltage does not work in a transformer for steping to different voltages. the instant your voltage goes from 0 to 12 vdc that is the same as 1/4 of an ac sign wave creating a split second of essentually ac power, producing your 35k plus ignition. that is why your car coil will only arc once on an old points system. you do have a point of the worn plug requires more voltage potenial to arc, but transformers work in the world of power ( watts ) not necessarly just voltage, so if ohm's law tells us anything a watt is the voltage multiplied by the amperage. Amperage is what creates the heat and ignites our fuel. So with a smaller gap less actual voltage is required thus leaving a little more amperage to create heat in the arc.

 

Yep,and another thing we Electricians like is laws..Ohms law to be exact. Platinum and Iridium both have a higher resistance than copper,so plain old copper plugs will yeild a more efficient ignition system than the Iridium or Platinum plugs.
JL

 

Your both wrong about when the plug fires and at what voltage level.
Usually the plug will spark jump at about 7 to 9000 volts in a good trouble free system.
The rest of the voltage (35k to 40k minus about 7k) is waisted and in reserve as the plug deteriorates and need more reserve to fire. The voltage used, goes up to cover the difficult spark jump conditions.
The most difficult times the plugs experiennce is under open EGR when the fuel is cut back to a lean condition and the ignition timing is advanced.
There is more science to this than meets the eye. It's not just only simple ohms law.
The resistance in the spark gap due to the A/F charges changing with throttle opening, calculated fuel injection amounts, plug conditions, leakages etc change all the time as the engine is running and needs the large reserve volrage available to keep the engine running over a long length of time or you would be servicing the ignition all the time.