Which coil

[Bazza]

I'm in the process of trying to get to the bottom on an intermittent misfiring fault when hot on my 1972 TR6. It runs fine when cold/warm but sometimes when hot the dreaded misfire starts at anything over 2800 rpm. Below this and again its fine hot or cold.

New electronic ignition, distributor cap and plugs hasn't helped. I believe the coil was replaced at the same time and wondered if it was the right one. There are no markings on it and the terminals are shiny new so I think it was replaced.

Was this the right one though. I've measure the resistance across the low voltage side and get 3.3 ohms, indicating a non-ballast type. Is this likely to be the right one?

 

I'm about to change the HT leads as well.

 

Thanks.

[TR6GAZ]

Its funny, I had the same problem with mine when I first got her...so I was rather clueless so I just replaced the lot, I fitted a lucus sport coil and its never done it since!

[jerrytr5]

Somebody has to ask.....are you running a red rotor arm, some of the repro black ones break down and cause this issue.

Jerry

[TriumphV8]

Although I am aware that I might open a box of worm I would like to tell

that a real good running TR6 PI needs a sports coil in the upper revs area.

Being a bit disappointed on the dyno a BOSCH mechanic recommended to

change to a red BOSCH sports coil with resistor.

 

With nothing more changed it made more power in the upper rev area.

Anybody is free to belive this or not.

 

When going below 2.5 Ohms it might be a good idea to check if points

or the electronic in use can handle that without problems.

 

But any coil without defects will work without misfiring.

Parts that get warm during use are subject to misfiring after some time.

These are coil, electronic, condenser and rotor arm and the power

supply itself. Even a new coil or rotor arm or condensor can be faulty.

[Clarkey]

Hi Bazza

Where is the coil situated?

I moved mine off the engine block and turned it on its side as a matter of caution as i believe( now I may be wrong) but they have oil inside and if there isn't enough they can over heat and break down.

Hat on waiting for incoming

 

Edited August 12, 2015 by Clarkey

[Crawfie]

Replaced my Lucas Sports Coil with an NGK one.

I had the symptoms you have had.

This was the only piece of so called good quality new "Lucas" stuff that had not failed.

Replaced with NGK , problems gone.

[astontr6]

Dear All,

 

The Lucas trade name is licensed to Elta Automotive, from TRW, these products are often not the same as the original Lucas - Birmingham Co .Products. The Logo is the same as the original but the contents may not be! The trade name Borg and Beck for clutches is the same, that that has been sold off to First Line. If you want an original B & B you have to buy an AP Clutch as this is their trade name now.

 

Bruce.

[Crawfie]

Replaced my Lucas Sports Coil with an NGK one.

I had the symptoms you have had.

This was the only piece of so called good quality new "Lucas" stuff that had not failed.

Replaced with NGK , problems gone.

The coil had failed!

Hence the replacement

[Bazza]

Just waiting for new coil and HT leads to arrive and may look at changing location. I'll let you know how it goes.

[Bazza]

new sports coil and high performance HT leads fitted and misfire seems to have gone. out for 40 mile drive and not one misfire. out again tomorrow so hopefully all good.