Tune-up Foul-up

[PeterK]

Art -
Good writeup!

Have you seen a replacement for the ratchet clip (Moss p/n 163-740 n/a) for the adjusting nut. Mine's missing on all 4 dizzys I have and I need one or two.

Anyone? Thanks.

 

[DrEntropy]

Nice, Art. Only thing I'd add is to be certain the rotor/cam is "bottomed" on the mechanical advance stop by rotating it CCW before moving the dizzy body to the CW "trigger" point.

Peter: I just went thru my "small but important" LBC "GOK" (God only knows) bits bin. Thought there may be one in there, but no joy. Mebbe Tony?


But if ya need some brake cylinder "C" clips for an MGB, ~I~ got 'em. Must be half a dozen of th' infernal things in there. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Deleted member 451]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]30,000 miles from a coil?? Unbelievable,
to say the least.
[/QUOTE]
Tisnter,
I drive the car to work most days and every weekend, about 5-6,000 miles a year. I put the coil on right after I bought the car almost 6 years ago. The only electrical problems I've had were generators (3) and voltage regulators (4). Got tired of that so I switched to a $40 alternator about 6 months ago now I have bright lights and no problems.
I think the reason I have so few problems is because I drive it a lot. I averaged my parts and repair costs the other day and it was less than $100 per month for the 6 years I've owned it. This included a R&P steering conversion, an OD transmission, radiator recore, and a differential rebuild.
Not bad for a car that had set for at least the prior ten years.
The really good news is that the car is worth more now than my purchase price plus all the stuff I've done to it. Zero cost of ownership is a fine thing.

 

[GB1]

Dale:

I have had the same Lucas Sport Coil for over 20 years w/ no problem at all (knock on wood).

Pat

 

[DrEntropy]

I don't recall the last coil I replaced on one of my cars (talkin' the RUNNING ones, for you smartbutts). Likely the Alfa after I got it in '98.

 

[TR3driver]

Re: Tune-up Foul-up and More

I've had a rotor go bad once in 56,000 miles, and a distributor in about 90,000 miles.

In both cases I was at a total loss to see what had worn.

How would one tell before it's too late? Is anything visual?

Just my $.02 ... when a cap or rotor fails without apparent mechanical cause, it generally indicates they are being overstressed electrically. Everyone likes to jazz up their coils and trigger systems, without considering that the higher coil output creates extra stress on the other high voltage components (and the coil itself). Of course the plug gap normally limits the peak voltage, but all it takes is a minor failure (like a worn plug or a loose connection) to allow the voltage to rise higher and start jumping places it shouldn't.

A common failure point on the TRactor motors is where the screws in the cap pierce the plug & coil wires. If you use "carbon core" wires, the carbon tends to burn out around that point and create a high resistance.

Friend of mine had a set of Lucas suppression (resistor) plug caps on his 4A ... after his brand new rotor shorted in less than 200 miles I found that one of the resistors had come apart inside.

After that 'interesting' trip, trying to hunt a TR4A rotor in the wilds of southern Oregon, I now carry a complete distributor, with points, cond, rotor, cap & wires; with me on long trips. Wrapped in plastic and stuffed in the center of the spare tire.

 

[PeterK]

Re: Tune-up Foul-up and More

And I've read that solid wires can cause interference with electronic ignitions and should be avoided.

The only time I EVER had a coil problem was driving my Fiat 850 Spider. I was going over the old Cooper River bridge in Charleston, SC. As I remember, it was relatively long bridge shaped in an arc so there was a somewhat steep incline as the bridge arc'ed and had no railings on the sides. If we looked out over the the doors, all you could see was the fall down to the river.

The Fiat 850cc engine didn't have a starter other than the passenger and when it (the engine) got hot, the vent hole on the overflow tank lid would squirt a thin stream of water directly on the coil wires and short out the ignition.

So there we were "I think I can-ning" over the top of the bridge. And the 850 was sputtering along trying to make grade. Well we made it but never forgot the terror in that little car.

 

[TR3driver]

Re: Tune-up Foul-up and More

And I've read that solid wires can cause interference with electronic ignitions and should be avoided.

I've read the same thing.
Makes sense to me that strong EMI could foul up electronics, but my take is that it's only important you suppress the EMI, not necessarily that you use those cheap carbon wires. And the stock TR2-4 cap already has a suppression resistor in it.

Another solution would be to use an MGB dizzy cap, which fits the TR dizzy but takes ordinary push-in wire terminals instead of the pointed screws.

I had to remove the suppression resistor in the cap (MSD burned it up) but found some plug wires with suppression resistors incorporated in the plug boots. They've worked great with both the MSD and the Crane XR3000 for more miles than I can count; and pretty much eliminate interference with the radio. It's a shame they don't make them any more.

I have changed the coils on my Triumphs from time to time, generally in the theory that it might be the problem (but it never is). The one exception is when that suppression resistor burned away ... the MSD kept right on throwing a spark even when it was from the coil tower to a side terminal. Coil still worked, but with that big carbon track through the tower, I felt it best to replace it /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

Oh yeah, I've replaced a couple when they started leaking, too.

 

[TexasKnucklehead]

Re: Tune-up Foul-up and More

Bill,

I posted about a similiar problem over the weekend (What is broke down) and ordered the Petronix. I hope it resolves my problem as well.

I have had 2 rotors fail in this TR6. The first was after 3,000 miles, the second in about 200 miles. Both were BorgWarner units. Replaced them with LUCAS parts and haven't had a problem since -until this weekend. All other ignition parts are stock Lucas components.

Apparently rotors are known to crack in the center, allowing the spark to go down to the shaft, instead of out to the plug. Even knowing it was bad, I could not see a crack, or any evidence that it was bad. The only way I was sure, was to replace it. There is no way to forsee or predict this kind of event.

Jer

 

[Guest]

Re: Tune-up Foul-up and More

The Crane XR3000 unit is a good setup because you can leave the ignition on without the engine running and have no fear of burning up the unit. Not so with the lesser Crane or even the Pertronix. Good for about 2 minutes before they are damaged or completely fail. Ask me how I know this. Many, many phone calls to Crane before they would admit this.

 

[TR3driver]

Re: Tune-up Foul-up and More

Not so with the lesser Crane

I believe that is no longer true. Definitely true with the 'old' unit, but they redesigned a few years ago, and now even the XR700 shuts down it's output when the engine is not running (to avoid overheating both the output transistor and the coil).

You can tell the difference because the redesigned unit has an LED on the brain box (which shows when the beam is interrupted even if the output is shut down). The redesign also allows it to work with either ground polarity (with some wiring changes).

BTW, Pertronix specifically warns against leaving the key on for any length of time.

FWIW I was running an XR3000 in TS39781LO before it was wrecked. It's one of the few 'improvements' that I will NOT be moving to the project TR3. My plan is to use a Pertronix to trigger an MSD 6. (The low current draw of the MSD box should eliminate the possibility of overheating if the key is left on.)

 

[Tinster]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:] I averaged my parts and repair costs the other day and it was less than $100 per month for the 6 years I've owned it. Zero cost of ownership is a fine thing.

Holy Moly!!! $100 a month? I'm at $1,910 a month for
24 months of ownership. But my cost per mile driven has
fallen dramatically from over $200 per mile driven to now
$35 per mile. Hopefully, another few $thousand and I'm all
done--- except for a paint job.

But I'm having a blast finally driving the car now!!

d

 

[70herald]

Re: Tune-up Foul-up and More

Not so with the lesser Crane

I believe that is no longer true. Definitely true with the 'old' unit, but they redesigned a few years ago, and now even the XR700 shuts down it's output when the engine is not running (to avoid overheating both the output transistor and the coil).

You can tell the difference because the redesigned unit has an LED on the brain box

Absolutely true, I just put a Crane XR700 (with the LED light on the control box) on the Herald and it works perfectly. It most certainly shuts off after a few seconds of the engine stopping (when the ignition switch is on) I checked it with my meter. This is the main reason that I chose the Crane over the Pertronix. the fact that I was warned about warantee problems for overseas customers with Pertronix sealed the deal.
The Crane is just as easy to install providing you can figure out the instruction manual. Some day I will get around to writing up a simple, clear instruction set because the instructions from Crane are terrible.

 

[DrEntropy]

Re: Tune-up Foul-up and More

I put a Crane unit on a V-12 Jag a while back, the "instructions" were a bit cryptic indeed.

 

[TR3driver]

Re: Tune-up Foul-up and More

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif It would help a lot if they would just write a separate sheet for the XR3000 instead of mixing them together with the XR700.

 

[piman]

Re: Tune-up Foul-up and More

Hello Bill,

I notice you said that your distributor was due for an overhaul. Electronic ignition will not fix that. And, as you say, the car ran better than it did before the installation of the Pertronix, then the points were not set correctly.
I have not seen anything that convinces me that electronic ignition gives a noticeable (from the driving seat) performance increase over a points system on cars of this era, with the proviso that the points are set correctly. Basically these engines do not require special ignition systems as they are relatively low powered for their capacity. Modern high compression lean burn engines could well be different.

Alec

 

[poolboy]

Re: Tune-up Foul-up and More

You are not going to gain horsepower by installing a Pertronix. You will get a more forgiving ignition system if the dizzy has normal wear. I think that my engine starts up faster and seems to run a little more smoother/even since I made the switch.
I do as the Pertronix instructions recommend though and keep the points and condensor,(in the boot) just in case.
Internal combustion may be a little more complete because I felt comfortable opening my spark plug gap by .010 inch.

 

[Deleted member 451]

Re: Tune-up Foul-up and More

I agree, It's really a matter of not wanting to mess with them any more.
The last few sets of points I've had wore rather quickly, may have been due to a worn distributor or the quality of the points these days. I decided to give electronic a try.