Put a new coil in the car last summer. Lots of drivability problems lately. SO, just for fun I tested it.
Secondary windings are down to 11.81 ohms. Suppose to be 12.8-13.3 ohms.
Same goes for the power pins(3). Suppose to be .50 ohms +/- .005. They are at 1.3,both sides.
Guess I shall try to get my money back.

Who makes the best quality coil?

Motorcraft.

DC resistance readings of coils is seldom a reliable indicator of the coil's servicability except when the reading shows a complete open or the readings vary by a very great amount.

Steve

Originally posted by projectSHO89:

---

DC resistance readings of coils is seldom a reliable indicator of the coil's servicability except when the reading shows a complete open or the readings vary by a very great amount.

Steve

---

They have always been reliable to me =O personal expieriences change I guess.

If you are burning up coils fast most of the time its because of an open spark plug wire or bad spark plug etc, something to make the voltage spike high. Or just a cheap crappy coil.

I have had 5 2.5 contour in the last month all running very crappy when cold, either won't idle at all or the idle is very irratic and engine misses, setting codes p0300 - p0306 (missfire codes) and p0171 and p0174 (exahust lean bank 1 and 2)

EVERY SINGLE CAR WAS LEAKING LOWER INTAKE GASKETS!!!

Very easy to check if you have a scan tool that you can read engine data with (yes I know, who the hell has one of those right?) The short and long term fuel trim will be very high, like +30%, spray butt loads of carb cleaner along both sides of the intake gaskets and the fuel control should drop like mad.

Of course if you dont have a scanner, you will definately hear a change in the way the motor runs when you spray carb cleaner along the gaskets.

Its a good indication also that its the intake gaskets if it runs better when the engine warms up - because the gaskets are rubber and start sealing when they get hot =D