Thread: I am a bit embarrased to be asking this.....

Usually Rovers of this vintage had a resistor wire from the ign switch to the coil which served the same purpose as a ballast resistor. It was made of stainless steel or something that was impossible to solder to. Usually white with a blue? trace.

They then had a separate normal wire from the starter solonoid to the coil to give 12 volts on cranking( or whatever the volts dropped to with the starter load).
The coil was rated at 7-8 volts or so and running was supplied with 7 -8
volts via the resistor wire.

Have you considered that you may also have a crap radio? ALL Japanese radios have poor AM sensitivity as the problem in Japan /USA etc is cross talk because there are so many stations. Some of the worse ones also have poor selectivity, and may pick up harmonics of different frequencies.
Regards Philip A

Originally Posted by oldrover56

I am still battling this radio noise.

I think I may have found the problem.... the coil + has full 14v battery voltage on it when running, I thought these had a ballast resistor on an 8v coil?

That would certainly explain the amazing 25-30mm spark it can generate.
Coil runs very warm too.

The wiring diagram shows a ballast resistor for the conventional distributor but it is a bit vague about the electronic module version, does anyone know if it should have a ballast?

There are 3 wires from the coil to a 3 pin rubber connector but with only 2 wires connected to it - full battery voltage, and an earth. According to the previous owner there was a wiring short and it was rewired by an auto elec. so anything is possible. That explains the different wire colours anyway.

Cheers,
Terry

There isn't a ballast resistor fitted, as the electronic switching, unlike points, doesn't switch all the way to earth. So on cranking there is still full spark. You only need 2 wires to run a coil + and - connections. Any other connector is an earthed shield (braid).

Certainly possible someone has swapped out the coil, so beg/borrow/steal an original coil and fit that instead. Coils that are not matched to the amp can have significant problems. PM me if you want a standard LR electronic coil, I think there's still a couple out in the shed I swapped out during upgrades.

PhilipA,

There is definately no ballast wire, the whole bundle from the coil to the starter solenoid were replaced by the auto elec.There may have been one once, who knows?
I think the radio is ok, the ignition hash also wipes out an FM cb and a VHF FM CFA set. I can also hear it on radios in the house 20m away.

bee utey,

Thanks for that info, sounds like a good clue.
I will remove the coil tomorrow to read the numbers on the bottom, perhaps you can tell me if they match the genuine coils you have?

Cheers,
Terry

Took photos of the bottom of the coil.
Can anyone confirm this is a genuine coil for a late 85 V8 with electronic ign. module please?
Thanks
Terry

Originally Posted by oldrover56

Took photos of the bottom of the coil.
Can anyone confirm this is a genuine coil for a late 85 V8 with electronic ign. module please?
Thanks
Terry

Looks like the original Lucas one. Says Lucas on the insulator? Clamped on top of the amplifier? I usually bin them as when I meet them they are dead already. They then get my Bosch ignition amp conversion as a rule. Can't help unless the later Bosch OEM coil is compatible.

Hi bee utey,

Thanks very much for that.
Yes says Lucas on the module base. Sorry second pic didn't get uploaded.
This coil works very well indeed - probably too well.
I am still a bit suspicious of the 3 wires to the coil, 1 14v, 1 earth, and the 3rd goes into the rubber 3 pin plug and stops.
This could have once been a resistor connection, I know you say it doesn't need it, I am going to connect a temporary resistor and see what happens.

I should have the electrically quietest motor in existence given the work I have done to shut it up.

My ex auto elec son in law can't figure it out either. Says Landrovers are sh*t anyway (Ford man)

Cheers,
Terry

The extra wire could go to a capacitor. These act as short circuits of ac signal to earth. The ac signal causes radio interferance.

Well, I fixed it !!!!!.

OK I know I said that once before.

Last thing I tried was a resistor in the supply - Wouldn't start and wouldn't run. bugger.

Things done to shut it up....

New inductive plug leads.
Closed up plug gap to 0.5mm
Checked rotor gap. ok. cleaned aluminium plug lead contacts.
Checked radio grounding, ok.
Radios fed thru an inline filter.
copper braid guards to firewall, and bonnet to firewall.
Tried another coil, no difference.
Copper braid over the coil to distributor HT lead. Grounded one end.
Copper braid over ignition module leads checked grounding at coil end. ok
Checked grounding of the antenna coax both ends. ok
Tried 3 different antennas. no change.

All this made the FM band and the UHF CB usable. AM band still useless.

SO, the final fix....?
Covered the antenna coax exposed in the engine bay with copper braid, grounded to the firewall.

WOO HOO no ignition noise !!!!

FIXED at last.

Thanks for all the suggestions guys.

Cheers,
Terry