Subject: [TR] Ignition question (and hello!)

From: Malcolm <[email-masked]>
Date: Sun, 15 Jul 2012 23:34:17 -0700

Hello list,

It's been a very long time since I have sent a message to the team.net list
Triumph.  Some of you may remember me!

Anyway, I have now got enough time on my hands to tinker again with my 1962
TR4.  Also, this year it is fifty years old, so I feel somewhat obligated
to pay attention to it.  I've got a bunch of new parts on it now, including
a stainless exhaust and new tacho/speedo cables, and have been trying to
get it to run properly.

I have fairly bad backfiring (through the carbs) under load when
accelerating.  I have balanced the carb inlets, the mixture seems OK, and
I've done the static timing.  I have new air filters (K&N) on order.  I
suspect that this is an ignition problem, though, and the Haynes manual is
dismal when it comes to troubleshooting the distributor.  Nearly every test
involves "compare your stuff with new parts, and replace them if they are
worn out".

My big question is: how much should I be able to rotate the distributor
rotor?  A little?  A lot?  15 degrees?  30?  Should it snap back to a
position at rest or just flop around?  I am trying to tell if the
centrifugal advance springs need replacement.

Will the K&N filters require me to fiddle with the timing?  They are
56-9327: http://www.knfilters.com/search/product.aspx?prod=56-9327

Has anyone got glowing recommendations, or horror stories, for electronic
ignition?  I've been scouring the Web and so far have not found a clear
winner.  I could rebuild the points (a la Distributor Doctor, or Advanced
Distributors) - or get Petronix, Hot-Spark, or some other drop-in
electronic replacement.

I am not building a concours car.  I want it to be reliable, running on
pump gas, with minimal roadside surprises.

Thanks!
-Malcolm

** [email-masked] **

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From: Bob Labuz <[email-masked]>
Date: Mon, 16 Jul 2012 08:20:43 -0400

Malcolm,

When I see/hear backfiring, I always think timing. If you static time 
your distro, then set 4 degrees BTDC you should be ok for most driving.

For me on my 3 and 4, I do the same thing but then use the micro 
adjustment to fine tune so I don't get any pre ignition and the engine 
pulls good in all gears.

If you think your distributor is worn out, then get it rebuilt. I had 
mine done on my 6 by Jeff Alexander. He does a good job and the price is 
good.

No experience here with electronic ignition. I go with  stock on my 3,4 
and 6 and are very satisfied.

I have rarely had problems with spark but the few I have had are bad 
points, broken connection on the low tension lead inside the distributor 
and a bad distributor cap.

Not sure on the rotation degrees on the distributor rotor, but I am 
guessing at least 5 degrees each way, (maybe a bit more) and it should 
snap back.

Doubt the filters are the problem. But do check the oil level in the 
dashpots.

Bob

  On 07/16/2012 02:34 AM, Malcolm wrote:
> Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: "Wbeech" <[email-masked]>
Date: Mon, 16 Jul 2012 08:58:33 -0500

Malcolm,
You are right to think electrical as long as your fuel problem is not
starvation.  You should be able to check your timing with a light and see if
the low and high RPM setting are within spec.

Breaking down under a load, as you describe, seems more to point to one of
the following: Points too closely set, bad plug(s), bad plug wires, weak
coil or bad condenser.  I would check through these things in this order and
I bet you fix it so you can be on the road again by the weekend.

Good luck,
Bill

Bill Beecher
'58 TR3A TS/30766L "Tarbaby"
'62 TR3B TCF/2549L
www.triumphowners.com/1566
'68 Land Rover Series IIa 88" "The Beast"
"If you think you have everything under control... You're driving too slow"
M.Andretti

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]] On Behalf Of Malcolm
Sent: Monday, July 16, 2012 1:34 AM
To: [email-masked]
Subject: [TR] Ignition question (and hello!)

Hello list,

Anyway, I have now got enough time on my hands to tinker again with my 1962
TR4.  Also, this year it is fifty years old, so I feel somewhat obligated to
pay attention to it.  I've got a bunch of new parts on it now, including a
stainless exhaust and new tacho/speedo cables, and have been trying to get
it to run properly.

Has anyone got glowing recommendations, or horror stories, for electronic
ignition?  I've been scouring the Web and so far have not found a clear
winner.  I could rebuild the points (a la Distributor Doctor, or Advanced
Distributors) - or get Petronix, Hot-Spark, or some other drop-in electronic
replacement.

I am not building a concours car.  I want it to be reliable, running on pump
gas, with minimal roadside surprises.

Thanks!
-Malcolm

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage:
http://autox.team.net/mailman/options/triumphs/[email-masked]

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From: Geo Hahn <[email-masked]>
Date: Mon, 16 Jul 2012 07:18:04 -0700

On Sun, Jul 15, 2012 at 11:34 PM, Malcolm <[email-masked]> wrote:

> position at rest or just flop around?
>

As I recall the rotor should move about 100 on a correct TR4 distributor.
When you move it I think you want it to snap back sharpish... if it is
reluctant or 'flopping around' then it needs attention.

You might look at the number on the distributor body as through the years
it may have been swapped with something slightly different from original --
I'm thinking it would have been 40735A or 40795A.

In any case, it is pretty simple to get the distributor on the bench and
diassembled to the point of examining, cleaning and lightly lubing the
weights and springs.  There will probably be one 'thin' spring that sits
secure on the posts and one 'fat' spring that fits loosely (because it
doesn't come into play until advance has operated aways).

Geo

---

From: "Randall" <[email-masked]>
Date: Mon, 16 Jul 2012 08:28:01 -0700

> accelerating.  I have balanced the carb inlets, the mixture 
> seems OK,

Just a thought, have you tried to check the mixture under the conditions
where the problem happens?  I'm wondering if perhaps you have a fuel
delivery problem that is causing the mixture to go lean under load.  

I would also be looking at the wires inside the distributor.  They flex
constantly, so sometimes can break inside the insulation and be intermittent
without being visibly bad.  The test is to hook up an ohmmeter and gently
tug on the wires.  Note that there should be a ground wire between the
moving point plate and the distributor body.  You'll need to undo one of the
mounting screws to check it.

> rotor?  A little?  A lot?  15 degrees? 

15 degrees is about right.

> Should it snap back to a

It should spring back at least partially.  I wouldn't describe it as a
'snap' though, and usually it won't go all the way.

>  I am trying to tell if the

One good overall test is to put a timing light on the engine while you
slowly rev it up and back down.  It's not even really necessary to mark the
pulley for the various advance points, just watch that the TDC hole moves
smoothly to the right as rpm increases, and back to the left as you let it
down.  If it flops to full advance, or jumps around all over the place, or
doesn't move at all, you've got a sick distributor.  

The main point is how the mark behaves, I generally don't bother trying to
check the amount of advance.  But if you want to, I've put some curves up at
http://goo.gl/4LcFq
for a few of the various TR distributors.  (The list is not exhaustive, so
your car may be wearing something else.)  Note that the figures given are in
distributor degrees and rpm, which is one half of what you will measure at
the crankshaft.  IIRC each 1/4" on the edge of the pulley is roughly equal
to 5 (crankshaft) degrees of advance.

Also, if the car has been stored a long time, it is probably worthwhile to
disassemble the distributor to clean and lubricate it.  Putting a few drops
of oil under the rotor will keep it lubed if done on a regular basis, but of
course that didn't happen while it was stored.  I like to put good quality
grease inside the pivot points and where the weights rub on the support
plate.

I'm kind of sour on electronic ignitions at this point.  They do have some
advantages of course, including less maintenance required but the overall
reliability seems about the same as points to me.  I am currently running
points in my "daily driver" TR3, after having some weird problems with the
Pertronix.  The Pertronix will apparently not fire the plugs when the
battery voltage is way down (but still high enough to turn the starter).
The root cause was a bad battery, but it started fine on points while it
would just crank and crank with the Pertronix.  That's not my only
misadventure with electronic ignition, just the most recent one.

Points will still fire even when the battery is way too dead to turn the
engine.  I proved that again just a few weeks ago, when I accidentally left
the lights on while I went in to work.  By the time I tried to leave, the
(gear drive) starter would only grunt.  Even the warning light on the dash
was way dim.  I set the choke, pushed the car up to walking speed, jumped in
and popped the clutch.  It caught first time, and I drove it home.

Of course, not long after I switched back to points, the condenser died.
Guess maybe I should have put a new one in to begin with, instead of keeping
the 40+ year old one that was with the car when I got it. <g>  But a spare
set of points & condenser are a lot cheaper (free if you save the "known
good" ones from your last tune-up) than carrying a spare electronic
ignition.

-- Randall

---

From: Malcolm <[email-masked]>
Date: Mon, 16 Jul 2012 22:30:18 -0700

Thanks all.  Chris, I will probably do this tomorrow.

I filed the points and set the gap today, the car runs a lot better.  Only
an occasional stumble on acceleration.  Also retuned the carbs (rear one
was running rich) and advanced the timing a lot.

I've also bought a new set of points and a condenser.

I'd like to buy a "better" coil, since mine is probably fifty years old.
 Does anyone have any recommendations?

M

On Mon, Jul 16, 2012 at 9:42 AM, Chris Simo <[email-masked]> wrote:

> No harm in removing the two screws and pulling off your contact breaker
> plate. Make sure the weights move and the springs are intact.  If you have
> a mightyvac you should test your vac advance,  too. I recently had the
> rivet in a rotor come loose and was ground up into what looked like a small
> wad of steel wool.
> On Jul 16, 2012 5:06 AM, "Malcolm" <[email-masked]> wrote:
>
>> Hello list,
>>
>> It's been a very long time since I have sent a message to the team.netlist
>> http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: Malcolm <[email-masked]>
Date: Mon, 16 Jul 2012 22:40:02 -0700

Thanks Geo.  I tried the rotor again tonight and it does return back,
although it's not snappy like I would hope.

I also ran the car with the timing light and saw that it is floating a bit
at idle.  I've got new points to try, and I'll replace the coil, but I
foresee a rebuild in my future.

M

On Mon, Jul 16, 2012 at 7:18 AM, Geo Hahn <[email-masked]> wrote:

> As I recall the rotor should move about 100 on a correct TR4
> distributor.   When you move it I think you want it to snap back
> sharpish... if it is reluctant or 'flopping around' then it needs
attention.

---

From: Bob Labuz <[email-masked]>
Date: Tue, 17 Jul 2012 08:01:31 -0400

Malcolm,

I use the Lucas sport coils on all my Triumphs. I have never had a failure.

I have heard that some have had the sport coil fail.

Now on my 3 and 4, I have mounted the coil on the inside of the fender 
well in order to keep it cooler than it would be on the block. I am not 
sure it has helped but no failures yet.

I wanted to do the same on the 6 but because of the 6 cyl engine's 
length and the position of the distributor, the distance from a 
potential coil mount similar to the 4 would make a very long connection 
from the coil to the distributor. So that coil is still mounted on the 
block.

Petronix makes the flame thrower coil. Maybe others will chime in on 
their coil choice.

Bob

---

From: Malcolm <[email-masked]>
Date: Tue, 17 Jul 2012 21:18:33 -0700

Tonight I replaced the points (and pulled off the breaker plate to check
out the springs).

Both springs were there, but loose on their shafts.  I pinched one a bit so
it wasn't as loose, and sprayed some brake cleaner down around the weights
to try to remove some of the crud.

Also cleaned off the contact plate as best I could, which should hopefully
help the action of the vacuum advance.

This distributor should be rebuilt, but for now it is OK.  I put the (poor
quality) "new" points in, set the gap, and the car idles much better now,
running smooth at 6-700 RPM instead of 1100.

I suspect that a proper clean-out with new springs will help even more.
 This distributor is marked with service mark 40842 A, which appears to be
a TR4A low-compression unit?  Odd that it's identified for a 4A, since the
date code is clearly 162, pre-dating the 4A by some years.

M

---

From: "Randall" <[email-masked]>
Date: Tue, 17 Jul 2012 21:59:53 -0700

> a TR4A low-compression unit?

I have 40842 listed for low compression TR4 (not 4A) 61-65.  It's even
listed in the TR4 section of the workshop manual.

-- Randall

---

From: Geo Hahn <[email-masked]>
Date: Wed, 18 Jul 2012 09:03:35 -0700

> a TR4A low-compression unit?

It is my understanding that the only differences among the 25D distributors
were the vacuum advances and the springs.

You may be able to make it suitable with just a spring change, but... I
think the usual vendors supply you with a bunch of springs and leave it to
you to work out which 2 are what you need (i.e. there is no packaging
marked 'TR3A springs', 'TR4 Springs', 'TR4A Springs', etc.).

There is of course equipment that can be used to set the advance curve but
since that is beyond the reach of most of us I think you can approixmate
the correct curve with some guess work, trial & error and a timing light
(with a degree dial on it).

Geo

---

From: "Randall" <[email-masked]>
Date: Wed, 18 Jul 2012 09:31:19 -0700

> were the vacuum advances and the springs.

Also the stop that limits maximum advance.

-- Randall