View Full Version : TR2/3/3A 58 tr3 ignition + frustration but smashin' bugs

09-18-2008, 04:04 PM
Just getting my TR3 back on the road....What a BLAST!

I got it going yesterday and drove it in short spurts all afternoon. I have discovered an ignition issue as well as some suspension things going on, front and rear.

Ignition symptoms are a random missing at low RPM (idle) and also at higher RPM(4000). It accelerates fine but then it starts missing intermitantly when I hold the constant RPM. Constant RPM in the mid range runs smooth with infrequent missing.

I have looked at the plugs and the originals had #2 cyl oil fouled and the other 3 cyl's were normal. I did a compression check with a warm engine @ 120psi per cyl. I guess thats normal. I replaced the plugs and drove it a while to see if the oil fouling would continue. When I checked the plug condition, all 4 were normal. I then cleaned the Dist. cap and checked the wire connections and cleaned them all. The points look OK but are not new. It dosen't look like the points are burned. I also cleaned the coil connection.

I'm thinking coil, I have a white ceramic rectange, I think resistor, hooked up on the front of the coil.

Could either one of these be bad? Whats the function of the "resistor"???

09-18-2008, 04:19 PM
The resistor would presumably be because someone has replaced the original coil with an "external ballast required" version. It limits the current through the coil and points, to keep them from overheating. The original coil had enough internal resistance to limit the current, so didn't need a resistor.

To check which type of coil you have, measure the resistance between the two low tension terminals. Around 3 ohms means it does not require an external resistor, less than 2 ohms means it does. Many digital ohmmeters aren't zeroed very well, so first check the reading with the probes held together and subtract that number from what you measure.

I doubt it would be the resistor; generally if they do go intermittant, the problem rapidly gets worse as the broken ends arc and erode. Could be the coil, though. You can try a brief test with the resistor bypassed, but I wouldn't drive more than a few minutes that way.

First, I would check the resistance of the plug and coil wires, from the terminal inside the cap to the plug/coil terminal. My experience has been that common "carbon core" wires do not work well with the stock distributor cap, and tend to burn away where the points pierce the wire. The value to expect depends on the type of wire, but they should be all roughly the same. Ordinary "carbon core" would be about 5-10K for the plug wires, somewhat less for the coil wire.

Also check that the carbon button in the distributor cap moves freely.

You could also hook up a timing light and see how bad the spark scatter is. A lot can happen to a dizzy in 50 years ... some of them have so much wobble that the points don't always close!

09-18-2008, 04:23 PM
Duke --
Hoping to join you soon in the "just getting my TR3 back on the road club."

I am not up on all the coil-and-resistor combo stuff -- if you search the forum you will find some explanations. However, a stock TR3 coil doesn't use a ballast resistor. If you've got the stock coil, you can bypass the resistor. I'm not a betting man, but I bet doing that won't cure your miss though. Coil problems don't tend towards that sort of intermittent miss.

How long has it been since the carbs got cleaned? Has your fuel been sitting for a long time?

09-18-2008, 09:18 PM
When you check the resistance of the plug wires wiggle the end at the distributor cap as you measure the resistance and see if it changes. If it does you have a bad connection at the cap connection. Carbon wires do that.

09-19-2008, 12:27 AM
OK I broke out the camera before the multi meter but am having difficulty posting pictures in a reply....how do U do dat?

I cleaned all the connections again and went for a drive, well dropped the Son at football practice and drove a little. The cleaning seemed to help on the low end but it still starts grumbling on the higher side of RPM. I tried a little choke and that helped so I'm leaning toward the carb. adjustment and cleaning. The gas is good and fresh, I drained and flushed the stinky stinky mess out of the tank and lines. Ended up replacing the fuel pump as the diaphram was "gooie" in the original pump. GOD this thing is fun to drive !!!

09-19-2008, 12:33 AM
still trying to add pictures and trying ythe file thing

09-19-2008, 12:38 AM
I'll use the meter in the morning to see what I can find.

09-19-2008, 12:44 AM
This one a a bit out of focus...the "love" bugs are out in the Deep South.
Well. this Ol' fashoned rogering was interupted abruptly by a reserected TR3 !!!!

09-19-2008, 08:27 AM
Yup, that's an aftermarket "universal" coil; which probably came with the resistor just for applications like this one that did not originally have one.
Should work fine, but I'd double-check that the polarity markings on the coil match your battery polarity. The car was originally positive ground, but it's very common to convert to negative ground. Also try tugging on the crimp connections, to make sure they are secure. I've seen enough crimps go intermittant with time, heat and vibration that I refuse to use them on my cars.

And those definitely look like carbon-core wires (again universal replacements).

BTW, there is supposed to be a rubber plug in that hole in the steering column (which is for filling the steering box with gear oil).

Also BTW, that dizzy cap is from a MG or something, but should work OK.

09-19-2008, 10:22 AM
Thanks for the information and advice Randall! I'll be ordering replacement wires and the such Today. After I get these gremlins out of the ignition I get to start figuring out why the wiper motor powers up when I hit the brakes !!! This car is TS31022 and still a positive ground...lots and lots of cleaning those little bullets in the near future.

Moses, When you get yours up and going LETS RACE!!

09-19-2008, 10:41 AM
I get to start figuring out why the wiper motor powers up when I hit the brakes !!! Wull, that's a new one on me; but be warned that many of the published wiring diagrams are wrong for your car. For example, the diagram that Mr Haynes claims is suitable for TR2, 3 and 3A is actually only good for TR2 and early TR3 (without self-parking wipers).

09-19-2008, 12:45 PM
Hey Duke;
I can't believe your restoring a tr3 in Jackson.
I've got my 57 tr3 running, but body work has been slow and tedious.
Are you going to the EMC show in Vidalia on the 27th?
I'd like to meet you, and maybe can help you with some extra parts.
As far as your car, it sounds to me like fuel--
and yeah, my TR is MUCH faster than my B, and an absolute hoot to drive.
McComb, Ms
ps several very sharp TR3s will be there.

09-20-2008, 11:29 PM
Hi Emmett,

I'm trying ot work it out to go with the Boss. I would love to drive the TR3 down but don't thinks its a good idea to take a long trip with so many open issues.......Thats 220 miles round trip, not sure if this cars up for that yet. Besides, I don't know how this rolling restoration will feel around so many of those show cars.

Are you going?

09-21-2008, 07:44 AM
I remember those love bugs from when I lived in Columbia and Spartanburg, though not fondly. Lots of guts that are hard to clean off and mess up your paint like seagull bombs.

09-22-2008, 06:08 AM
My TR3 distributor is positioned 90 degrees CCW from the one in the pictures. Your wires come off the cap forward, mine come off toward the fender. One of us can't be right.

09-22-2008, 10:52 AM
My TR3 distributor is positioned 90 degrees CCW from the one in the pictures. Your wires come off the cap forward, mine come off toward the fender. I think, if you'll look closely, it's just the cap that is different. The dizzy orientation is the same (otherwise the advance capsule would intersect the cylinder head), but the wire holes in the cap are turned. Which is why I commented that it was from a MG or something (sorry I don't recall offhand which car had that flavor of cap).

09-22-2008, 11:31 AM
Ah, but your sorta wrong, and yet your right.
Yours is the correct setup.
He either has a mgb cap, and the plug wires are rotated 90 degrees or his distributor base is timed incorrectly.

When I first fired my tr3 up the car had a mgb cap, and it took a few minutes to discover that problem. The previous owner had used the mgb cap and rotated the wires 90 degrees. I've since used the correct cap, and mine now looks like Daves.

09-22-2008, 07:56 PM
The wires are supposed to face toward the left fender. Here's a link to a pdf of the TR3 owner's manual:


The distributor photo is on page 32.

I have an excellent copy of this manual that I bought (from Moss?) a few year's ago. It has extremely clear photos that are great for reference. I strongly recomend buying a copy. It's a lot easier to work with a copy in your hand rather than a copy on your computer screen...

BTW, I just happened to have changed my wires, cap, points, condenser, and plugs this evening. When I went to check the ignition timing (with a timing light) I found that the mark on my pully was 90 degrees ccw of the timing mark on the engine. Anyone know what's up with that.