I was driving along the other day and when my car hit some potholes the engine hesitated but then caught again. Strange? When I got home I poked around and when I took the rubber cover off the ignition coil, the negative post just about fell out!!



The plastic at the base of the terminal had broken away. So I picked up a new coil and prior to installing it, I checked the primary and secondary resistance values. The measured values were:

Primary 0.7 ohms - However, the spec in the ROM calls for 0.5 ohms +/- 10% so just a bit outside.
Secondary 8.3 k ohms - but spec in ROM calls for 6 k ohms +/- 10% so quite a bit outside.

I went ahead and installed the new coil. Start up and idle were fine but after a warm up, when I pushed the engine up over 4,500rpm it seemed to lack power. I'm thinking the resistance variation might be the cause?

The new coil is a Bosch also but the can is silver my old one is black.

Did Jaguar ever release an altered spec for the coil? I don't see one anywhere but you never know. I will try and find out the new coil's specs.

Cheers,

Allan