Today, while I was installing new ignitions coils on my 1990 XJS with Marelli, I noticed a problem with the new coil.

If you take a look at the picture below you will notice that the distributor connection does not have the normal connection, it has a small pin instead of a socket. If I tried to use the standard spark plug wire there would be no connection to the coil. (This coil was purchased from Rock Auto).



In order to make this coil work I had to go the the auto parts store and buy a cable that had the correct pin connector. On the other end of the cable I had to crimp on a proper terminal that would connect to the distributor cap.

The picture below shows what a proper coil should look like;



Now here is the strange part. The coil above is a Marelli. The picture below is also a Marelli but it has a different connection. Again, it would not work with the standard spark plug cables. I have no idea what cable would work with this coil since it only has a small contact at the bottom of the well.






So here is the warning...check any new coils you buy and make sure it has the proper contact to match your spark plug wires.

I'm glad I found this before I tried to start the car. A situation like this is not something I would normally consider as a problem and it probably would have taken a while to figure where the problem was.

Also, if the coil did make a spark jump to the wire it probably would work at low speed but then fail at higher speeds. Again, it would have taken a while to figure out.

Mark

 

Did you compare the part number? I can't imagine that Marelli would simple change something like that without it being a different part...

 

I once bought a URO Parts coils and they also had the same connection as this.
So that might be an issue of production year, certain coils made in certain year might have that connection, and URO Parts might have made the coils to that spec.

I had used them for 4 years eventually but usable without problems, even at 6500rpm.
At least they performed better than the coils done more than 70k km.
But when I replaced them the other day, of course the connection looked burnt like a old dissy rotor.

 

I checked the part numbers today. Both Marelli coils are number BAE504. I don't know why the contacts are different.

The Rock Auto part is URO # DAC4608. It has the pin style contact. It works perfectly with the correct cable.

Mark