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Broke Down Today

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deadair

deadair

Jedi Hopeful
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I finally got my TR3A registered and insured. Today I decided to give it a good workout. After it warmed up, it ran fine for about 25 minutes and about 15 miles. Toward the end of my run, I noticed it sputtering on acceleration. When I got ONE BLOCK AWAY from my house, the engine just quit. The starter would barely turn over. I was on a hill and tried to jumpstart it, but that didn't work either.

My suspicion was that the generator was unable to keep up with the batter drain from the new electric fan I recently installed and it drained the batter. So I humped home, got my truck, took out the battery, brought it home and recharged it. When I thought the battery had a sufficient charge, I brought it back and installed it into the car. No joy. The starter barely cranked and there was no hope of getting the engine to start.

I went back and re-recharged the battery. Repeated procedure. Still no luck. Finally, I gave up and called a tow truck.

Now I'm wondering how to troubleshoot this. My guess is that, once the car completely cools off, it will start up without any problem.

My worst fear is that the pistons sizes are incorrectly matched to the cylinder bores (I had the sleeves bored out and fitted oversized pistons back in the day). However, the engine seemed to turn over fine, even when hot. So, before I go down the road of a complete engine rebuild, I'd like to eliminate any simpler causes.

I've driven the car before for much further distances, so I'm not entirely sure how to approach this problem.

Any ideas?
 
Seems more likely to me that either the starter or the battery ist kaput, or perhaps both.

To verify that the engine isn't bound up, try taking out the plugs and pushing the car with it in gear (or turning it with the hand crank, if you've got one).

To check the battery, turn the headlights on and measure battery voltage under load. If it won't hold 12.6 while running the headlights, it's either discharged or bad. Or just swap in a "known good" battery from another vehicle.

Next, I'd try checking the voltage first at the battery, and then at the starter, while trying to crank the engine. If the battery appeared to be good before, but is getting sucked down below 9v, probably the starter is bad. (I had several of them fail that way, before I got fed up and converted to a gear-drive starter.) Of course, if the battery is staying up but the voltage at the starter isn't, there is a bad connection somewhere.

You didn't forget the ground strap at the LH motor mount, did you?
 
You called a tow truck one block away from your home? That was an expensive block.
 
As you described the sequence of events, it sounds like you recharged and reinstalled the battery twice before the car had time to cool down. That's nowhere near enough time to fully charge the battery.

I'm thoroughly convinced that the pistons are not the wrong size for the bore.

The generator should be able to run the fan (which shouldn't be running at cruising speed anyway) as easily as it should run the wipers if you were driving in the rain.

My guess is that the generator has failed which resulted in the battery running down and that you needed to give the battery more time to charge to give it sufficient juice to start the engine.
 
Yes that sounds like a bad electrical connection or generator, starter, or like Randall suggested no ground to frame from body. Does your choke cable get hot? Because what happens is the system will use the choke cable for the ground. Anyways, if you fear a problem with the rings and sleeves check the spark plugs for oil deposits. I was kinda reading between the lines and it sounds like the vehicle starts hard when it is hot. Most seasoned cars do, but not a lot harder. Problematically speaking, bad starting when hot often is a ring problem. If the sleeve ring stuff is an issue, the plugs will foul out quickly. However, do not confuse fouled plugs with just bad timing or weak spark because there many variables that can foul plugs, i.e. carbs, poor fuel, poor driving ect…, but if you have oil on the plugs that is more serious.
Steve
 
Regarding the condition of the battery. I even swapped the battery from my truck and had the same result. One other observation: The ground terminal (+) became very hot after attempts to start.

I don't recall having a ground strap between the engine and body, but will check for that. What confuses me is that this is only an issue when the engine is hot.
 
One more here to suggest grounding issue. Often assumed and overlooked.
 
deadair said:
Regarding the condition of the battery. I even swapped the battery from my truck and had the same result. One other observation: The ground terminal (+) became very hot after attempts to start.
Click to expand...

I'm asking this because I don't know: Isn't the TR6 a 6-volt system? Does jumping it or using a battery from a 12-volt cause any problem?

Thanks.
 
Lewis_McDorman said:
deadair said:
Regarding the condition of the battery. I even swapped the battery from my truck and had the same result. One other observation: The ground terminal (+) became very hot after attempts to start.
Click to expand...

I'm asking this because I don't know: Isn't the TR6 a 6-volt system? Does jumping it or using a battery from a 12-volt cause any problem?

Thanks.
Click to expand...

It's a TR3A and it's 12 volt, positive ground (I haven't gotten around to converting to negative ground, but it's on my to-do list.)
 
deadair said:
One other observation: The ground terminal (+) became very hot after attempts to start.
Click to expand...
Bingo! Whatever other problems you may have, you now know for certain that there is a bad connection at that post. Pull it apart, clean until you have bright, shiny metal on both sides, make sure the clamp is doing it's job (replace it if necessary).
 
Lewis_McDorman said:
Does jumping it or using a battery from a 12-volt cause any problem?
Click to expand...
As noted, even the TR2 used a 12 volt system.

However, I can remember when I was a kid, Dad jumping his 6 volt Packard from the 12v family car. The cheap jumper cables essentially acted as dropping resistors; got incredibly hot but would hold together for the few seconds it took for the Packard to light off. But I daresay he burned his fingers more than once, pulling the clamps back off.
 
TR3driver said:
deadair said:
One other observation: The ground terminal (+) became very hot after attempts to start.
Click to expand...
Bingo! Whatever other problems you may have, you now know for certain that there is a bad connection at that post. Pull it apart, clean until you have bright, shiny metal on both sides, make sure the clamp is doing it's job (replace it if necessary).
Click to expand...

I guess the working theory is as follows:

The generator is not generating enough juice to run the ignition system, so it is run from the battery. When the engine bay gets hot enough, the positive battery terminal expands enough to weaken the connection and the car wheezes to the side of the road.

Does this sound about right? It would be great if it were that simple. I plan to do a negative ground/generator conversion, anyway.
 
My guess is that you actually have multiple problems; starting with something wrong with the generator &or control box. The generator should be able to output 19 amps (even assuming you don't have the later 22 amp unit that is commonly sold as a replacement), while the ignition only draws a couple of amps. That should leave plenty of generator output to carry the fan, when the headlights aren't on. FWIW, I've been running a Hayden fan with a stock generator for about 6 months now, and it's working out reasonably well.

Plus the fan shouldn't run very much, unless you've got it wired to run all the time.

Why it won't crank is likely to be something else (unless perhaps it is a ground problem, meaning the battery can't supply power to the coil).
 
Update:

* Inspection reveled no ground strap.

* Charged battery.

* Cleaned battery terminals and inside of cables. Reconnected cables.

* Car started right up from cold.

* I disconnected the ground terminal from the battery and the engine kept running, even when the fan started up. At one point, however, I did notice a slight misfire when the fan started up again.

* I then turned on the headlights, with the fan running, and the engine kept running. When the fan started up again, the engine died. So, my conclusion is that the generator can't handle the extra amp draw when the fan starts up.

I'm going to do the negative-ground-alternator conversion and then cross my fingers.

Thanks to everyone for your help. Your input is much appreciated.
 
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