3 Ohm or 1.5 Ohm Ignition Coil

[MRG1965]

HI Guys and Girls, quick question, I need to replace the ignition coli on my TR4 (12V, non ballast, with points) has decided to die whilst the cars been in the garage for the last few weeks.

Have replaced it with a spare but the  writing on both the old and spare has long gone, but the engine fires first time wit the spare, but  not at all with the old coli, so I know it's the coil, after checking all the other possibilities.

Question is what 12v, non ballast resister coil do I need, 3 Ohm or 1.5 Ohm, to be honest other than one being 36W and the other being 18W I really have no idea if either over loads the ignition system or makes no difference or one makes a bigger better spark for better starting.

Any advice on which is the correct one to get would b appreciated.

 

Mark

[Steves_TR6]

I think the 3ohm coil is the correct one Mark

the 1.5 ohm coil sounds like a ballast coil to me.

in a ballast system the coil sees about 9v when the engine is running, and the full 12v only when the engine is cranking.

the idea is to boost spark power for starting, esp cold starting.

without a ballast a 1.5ohm coil will be dissapating a lot of heat, and won’t last long.

for out low use cars this might actually be ok!, but its not right.

personally i’d go for a quality 3ohm from bosch or another reputable make.

steve

[Lebro]

+1

 

[MRG1965]

Cheers both 3ohm it is.

 

Mark