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Triumph TR6 - Distributor hangover

Okay guys, put on your thinking caps.

I purchased my 6 in April. Over the past several months I have been rebuilding the suspension and overhauling the drivetrain. The engine ran great so I left it alone other than to change the oil and put in new ignition wires, plugs, points, condensor, rotor and cap. All of the sudden the car started to give me trouble starting. Every once and a while, always in the morning, it would turnover, but not start. The first time it happened, I traced the problem to a broken distributor rotor. The little notch that hold the cap in place against the shaft was broken off and laying on the screw head beneath the cap. I figured it was a bad part, so I replaced it. It started right up and ran great. The nex week, after several uneventful restarts, it happended again. I replaced the broken rotor, and it started up fine. The next day, it happened again. I found a different OEM manufacturer for the rotor. It was made a little differently, with a large tab inside the rotor and no metal piece on the opposite edge to hold it against the shaft. It looked beefier. I installed it and the car started right up. I drove it all day yesterday including 6 or 7 restarts with no problem. This morning, it wouldn't start. I removed the distributor cap expecting to find a broken rotor. The rotor is fine, but there is no spark getting to the plugs. I intend to investigate further, including rebuiling the entire distributor, if necessary. But if anyone has any idea what could cause this, I would appreciate hearing from you. Thanks.

Mark Hauck


You can do a simple test to see if you have spark at all.

Remove the cap and rotor. Lay the end of the coil wire NEAR a ground (the side of the head will work fine). You'll want about a quarter of an inch or so, certainly no more, gap.

Turn on the key.

Make and break the points with a screwdriver.


Problem is in distribution of spark.

No spark? Distributor itself isn't the problem UNLESS you have a points/condensor issue.

I went with the Crane ignition on my 73 and never fooled with it again.


Jim Deatsch

Thanks Jim.

I have spark to the dsitributor but not to the plugs so the problem is with the distributor.

I checked the rotor again after posting the earlier message and it is broken, like the others were. I have concluded that the rotor is breaking because the metal tip that comes into contact with the six contact points in the distributor cap is sometimes hitting the cap just above the contact points. This suggests to me that the distribur must not be spinning true. I suspect that I have a bad bushing which is allowing the distributor shaft to wobble out of alignment just enough to cause the problem. The fact that it only happens on a cold start suggests that the shaft becomes misaligned when the engine cools off over night.

At this point, I plan to pull the distributor and rebuild it. If anyone has any tips on doing that, I would like to hear them. I also plan to install the electronic ignition. Is Crane the way to go?

Mark Hauck

Hi Mark,

I had a similar problem with my TR (cracked rotors every so often), and couldn't figure out why, so I pulled the distributor and took it to a local shop thinking that the shaft may be bent. They took it apart and rebuilt it for $40, and I haven't had a problem since (2+ years).

I really like the pertronix since the car looks mostly stock and you can go easily back to points if you ever missed adjusting the point gap (e.g. if the EI failed).

Ignatius Rigor

Hmmmm. It ran before the new distributor compnents, but started kicking rotors after putting on a new cap. Could be the cap is faulty? It wouldn't have to be out by much to cause a problem.

A. J. Koschinsky

Listen to Tony, he speaks with straight tongue.

Remove the cap. Have a friend, sitting in the driver's seat facing forward, engage the starter. Watch the rotor. Is it spinning true?

Another possiblity.

Jim Deatsch

Thanks for the feedback guys. I changed out the distributor cap a few weeks into this adventure and it didn't fix the problem. I think I'm going to go the rebuild route just to be sure.

Ignatius, I purchased the Petronix today and plan to install it after the rebuild is accomplished.
Mark Hauck

Good idea on the pertronix.
Do I dare suggest that you read past threads on Ballast vs. non ballast ignition systems and the infamous ballast resistor wire? What year is your 6?
Rick C
Rick Crawford


Sorry for delay in responding. Good news to report.

I replaced the p & c with the Petronix ignition. I alos decided to put in the matched petronix coil. Since I did that, I have had no problems. The car ('76) starts right up. I just did a round trip to Northern Michigan (500 miles) and it ran great and started up every time. The petronic ignition system includes a collar that fits on the distributor sahft below the rotor. It's possible that the collar overcame whatever misalignment was occurring. More likely, it assured that the rotor was positioned properly on the shaft so that it did not collide with the distributor cap contact points which was causing the breakage.

I guess I will just hang on to the three extra rotors I bought in case of a problem starting away from home.

The coil is ballasted. I did not replace the ballast as one was not supplied with the coil. Is this something I should do and if so, where can you get them? I do not recall seeing them in the Moss or Roadster catalogues.

Mark Hauck

Mark, which Pertronix model did you buy? Last year I installed the LU166A (lucas 22D distributor) in my 74 TR6 but I could never get it to work quite right although the car runs like a charm with points. It just kept fading around 3000 rpm. I had heard that it might be because of the retard mechanism but I haven't been able to confirm. Anyway, it finally got eaten by my rotor but I'd like to give it another try if I could solve the miss. Thanks, Bill v.
B Vogan

To the best of recollection, when I had the same problem with broken rotors, I solved it with a different brand of cap.

I too have Pertronix in my 74 with stock dist. and it works great for me. I disconnected the vaccume retard and time it at about 10 degrees BTDC which made a huge difference with a whopping 7.75 compression!

T L Brand

Bill and Tim,

I have the Petronix Ignitor (Part # LU-166A). Still working great.

I appreciate the info on the timing adjustment. I also have disconnected and plugged the vaccum retard. I have noticed some problems with occasional roughness when accelerating from a dead stop. I do not currently have it advanced to 10 degrees though. I will try that and see whether it corrects it. Is that 10 degrees at idle (900 rpm)?

Mark Hauck


I set the timing at idle. I have an aluminum flywheel so things pick up pretty quickly and I don't notice any hesitation ;) I also have a "hot" coil w/o a ballast. How new are your plug wires? If the hesitation's intermittent, I'd look there.

Or you may have a carb issue going on. When these Strombergs are healthy, IMHO, they are great little carbs and easier to deal with Webers. They're easy to rebuild too!

Good luck,
Tim Brand

This thread was discussed between 13/06/2004 and 01/07/2004

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