Thread: Ignition Coil 3.9 V8

Originally Posted by BigJon

Does anyone know of a part number for a Bosch replacement coil? My local suppliers have no listing for Land Rover.

Any 12v coil will do the job. Some have different HT connections but that's about it.

Check the base of the original coil - does it say 9v or 12v ?
9v = ballast resistor type coil
12v = non resistor type

I thought any 12v coil would do, but I seem to remember from my past (trade school perhaps) that the incorrect coil can lead to early ignition module failure (wrong resistances, etc).

Yes it is a very specific Bosch coil which has an unusual resistance etc.
Bosch sold all their stock to an auto electrician in Melbourne I think.
Call Bob Tait on (03) 9541-5559 at Bosch technical assistance and he will give you the info.

Regards Philip A

Thanks Philip, I tried that number, but too late. Everyone has gone home for the weekend. I will try them again on Monday. In the meantime I fitted a new 12v coil for electronic ignition (Bosch) with no change to how it runs.

Sorry for the bum steer Jon .
That's the first I've heard of the LR coil having a specific resistance value.

Maybe I shouldn't have run one in my Morris Minor for the last 10 years .

I have run a Bosch electronic coil (the square ones) on my 96 EFI Disco for the last 4 years without any drama.

I recently changed my Bosch GT40R (meant for Ballast resistor) to a GT40 (for use without resistor), also removing ballast resistance wire and replacing it with 4mm wire (ran from the electric fuel pump wire).

Bosch GT40s are around $35-40. Make sure you ask for a GT40, not a GT40R.

It runs very nicely now, starts easier and has a bit more low down torque.

This is on a Rangie with a Pirahna electronic ignition.

Now I am not a tech but I know from bitter experience.
A Pirahna or other replacement transistorised ignitions must have a points type coil , as this type of coil is current limiting. They are only switches which take the place of the points
If you use an electronic coil you will blow up the transistors in about 10 seconds. Ask me how I know.
A factory high energy ignition limits the current going to the coil, and the coils are quite different, and each coil is designed to go with a particular ignition. I understand that the current draw cannot be too high for the amplifier.
I was told that you could NOT use a Bosch 727 with the Dizzy amplifier, and most shops eg Graeme Cooper will not do it. But the above is guy who has done it without problems. I run a Bosch 727, but I have a Bosch remote amplifier running through the Unichip. The Unichip will not run with a factory amplifier. ( or that is what I am told!!)

Regards Philip A