ignition coil problems

[robtthorn]

can any one tell me what would cause the ignition coil to burn up and foul the plugs in # 2& 3 cylinders after driving 10 to 12 miles in a 1997 toyota tercel

[killdaggy]

Thats not a big problem. You can fix that by inspecting if its not grounded. Maybe just replace it.

[jdmccright]

Toyota coils can fail without technically failing. They can pass the usual resistance tests yet still fail. Why? They can produce a spark, but isn't hot enough to fully ignite the air/fuel mixture. Your plugs are likely fouled due to the incomplete burn caused by a weak coil. Despite this, I'd highly suggest replacing with another Toyota coil because the aftermarket ones don't last very long and they typically do not come with a warranty.

Hope this helps!