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View Full Version : Lucas sob story (maybe you've heard of this before



Kira
06-27-2004, 09:41 PM
My big beastie...my Wolseley 6/99 decided to die on me yesterday...rebuilt engine mind you. Anyway we tore apart the carburettor checking for water, negative, checked the plugs..nothing wrong there, but it was only firing on 4 cylinders. Changed all the leads...no change, tore the distributor apart and cleaned everything.contacts the works. No change.....hubby washed the dizzy cap. Now #2 and #6 weren't firing, and as luck would have it...(side entry cap)those two leads were the top two leads....and a hairline carbon arc line was detected. We think we found the problem. All we have to do now is find another Lucas dizzy cap for a wolsely 6 cylinder C series engine, side entry cap. Can anything else go wrong with this POS? I love her when she runs..but otherwise can be a cantankerous old bitch. (hope cars can't read, she'd be devastated)
/ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/cryin.gif

Bret
06-27-2004, 10:29 PM
Hey Kira,

BTW Welcome to the forum.

Anyway can't give ya any advice on Wolseley's but it sounds like you've got a handle on it. Just wanted to let you know that you have my sympathy. For ya see I too had some unexpected “heartaches” in the garage this weekend too.

My wasted weekend (http://www.britishcarforum.com/ubbthreads/showflat.php?Cat=&Number=65861&Main=65861#Post6586 1)

Best’a luck to you two and let us know how it turns out?

/ubbthreads/images/graemlins/cheers.gif

Kira
07-01-2004, 04:39 AM
Well the latest is: I now have a new dizzy cap, cleaned contacts...then we decided to check the resistances on all the leads as we used new leads. As the coil lead had a few ohms more than the rest, we checked the old cap and found that the old cap had a resistance of 14 kilohms across the carbon rod that connects the dizzy cap to the rotor button. The new cap was registering about 2.5 ohms NOT kilohms. Bit of a difference eh? Needless to say we do expect that we'll have a nice hot spark once it's all reconnected to the car. If all else fails.....can I sell anyone a used Wolseley? LOL
Most ppl would never think about an inert carbon rod increasing in resistance...not even our whizbang young mechanice thought of it....so if you have a wonderful old car, that's not behaving itself......try your dizzy cap and carbon rod. You may save heaps of money!
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P.S. The replacement is NOT a Lucas part..Bosch and some other ppl make equivalents though.

Steve
07-01-2004, 10:48 AM
Good tip, something to keep in mind. I'll keep my fingers crossed that all goes well at the starting ceremony /ubbthreads/images/graemlins/grin.gif

Dave Russell
07-02-2004, 01:29 AM
[ QUOTE ]
we checked the old cap and found that the old cap had a resistance of 14 kilohms across the carbon rod that connects the dizzy cap to the rotor button. The new cap was registering about 2.5 ohms NOT kilohms. ---
Most ppl would never think about an inert carbon rod increasing in resistance...not even our whizbang young mechanice thought of it....so if you have a wonderful old car, that's not behaving itself......try your dizzy cap and carbon rod. You may save heaps of money!
P.S. The replacement is NOT a Lucas part..Bosch and some other ppl make equivalents though.

[/ QUOTE ]
Hi Kira,
I have measured the center carbon electrode resistance in several new & old Lucas distributor caps & found them to be from 10k ohms to 15K ohms. Your readings on the "defective" cap seem to not be unusual. The resistance may even be intentional to reduce peak current to minimize electromagnetic radiation or to increase plug life.

To put this 14k ohms into perspective, the distributor rotor to cap gap is likely to be around 60k. Additionally, the plug gap itself may be somewhere around 160k or more, for 220k total MINIMUM resistance.

Assuming that there are no resistor type plugs at 5k, or resistor plug wires at 3k to 12k per foot, the 14k center cap carbon represents about 6% maximum increase of total circuit resistance. Since the average coil puts out enough voltage to handle three or four times the 220k resistance, I doubt if there will be much gain from decreasing the center carbon resistance, unless there is already something marginal in the ignition system. You will likely have a good spark with or without the additional 14k. I wish you well.

The numbers I have used are subject to variables & they should be taken as an approximation only.
D

AndrewMawson
07-02-2004, 01:13 PM
Kira,

You may want to check out Landrover dealers for a distributor cap - I think that the 2.6 litre 6 cylinder Landrover uses the same distributor /ubbthreads/images/graemlins/england.gif

Kira
07-04-2004, 01:14 AM
Thanks Andrew but we got a new one, put it in...and wow what a difference..she's running like new again..now to fix up the interior. To have a healthy car again is like a blessing combined with a new birth. A Car is Born. /ubbthreads/images/graemlins/driving.gif