Faulty ignition coil making engine run rough?

[b3h3m07h]

The other day i noticed that my engine was miss firing when i was trying to start it and though it was a tad bit strange but after i drove it for about a minute it went away. Anyway i replaced the leads and spark plugs but then the problem seemed to get even worse. So i took of the coils and checked them all and 2 of them read around 6.67ohms and the other around 8.5ohms, would this cause a missfire and rough engine running? Also how much should i be looking at for a new one? Cheers

[88GreenVN]

The CAS can be a problem with a missfire on the 3.8L. Some have suggested cold water on the CAS if the car stops (when it gets hot and has started to play up.)

Dont know about the ohms - but I guess they should be the same....

[bradcad]

Without knowing for sure I would say high chance that's your miss. Second hand shouldnt be up for much, otherwise I hear they are worth around $200 odd new

[mischf]

When I bought my Series II VN the guys at the yard put a new coil in it cause they said it was running rough.

Primary resistance should be 0.3-1.5 Ohms.
Secondary resistance should be 5000-7000 Ohms.

[hazza]

Yeah check the O2 sensor if the car is runnin rough. But when u say it goes good do u mean the car will run like really bad then its like the computer kicks in and it runs like a baby again. i have the same prob but.

[VGV8Ute]

Generaly if a coil is begining to break down you will notice it gets worse as the motor heats up. Carbon tracking can cause a problem with coils in much the same way as it does with a distributor, check for tracks and clean with contact cleaner. Also check to ensure the dust caps at the ends of the leads are on and sealing correctly.