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Looking for clues........

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Jim Lee

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Hi all,

I posted a while ago about a strange state that my TR3a would get into after a thorough warm up. It runs fantastic when I first start up and run around for at least 15 or 20 minutes. Not exact on the time, and I don't think it is always consistent anyway but definitely this 'strange state' occurs well after the car is warmed up.
What happens is it is as if it is running on only one or maybe two cylinders which allows me to limp home but constantly scanning the side of the road for possible emergency pull offs. Having experienced a mechanical fuel pump failure on another old friend of mine ('63 Tbird) this seemed very familiar. I'm thinking the fuel pump is going and it's being kind enough not to strand me on the road. So I replaced with an electric fuel pump and after a few unrefreshing petrol showers while rolling around in the fall leaves and fallen oil it is working like a champ. Plenty of gas is getting to carbs. So someone suggested a stuck float valve or a maybe a SU piston that was sticking. Took apart both carbs last night and everything looked very kosher. Of course I cleaned out all passages for good luck as long as I was there.

Now I am begining to think about ignition stuff. Popped off the distrib cap and was kind of surprised to see that it wasn't all that clean in there. I have a Petronix ignitor that I put in when I got the car and it has been working fine since then. There was some corrosion showing on the rotor cap (I think that's what it is called). The thing that is plastic and conductive and swings around just inside the distrib cap and actually distributes the juice to the spark wires. I cleaned that up as best I could with some 600 emery cloth. Looks pretty shiny now and I am sure this won't hurt even if its not the problem. Also touched up the 4 contacts that this rotor arm touches. They were a little off color but not too bad. The distrib cap, wires and coil were new with the Petronix ignition stuff so we are only talking a few hundred miles on them.

In the course of replacing the mechanical pump with the electric I can testify as a reluctantly soaked witness that there are no blockages in the lines. One thing I am kind of grasping at straw with is the rubber hose that comes from the bottom of the tank to the hard line on the chassis. I have not replaced that and am wondering if it might be collapsing and shutting off the fuel under certain conditions (like when its hot?) but otherwise working fine. I haven't looked at it too closely but has anyone replaced that part recently? It seems that it would be very difficult to get to the tank side of whatever that hose connects to to replace it.
The carb side is obvious.

I haven't had a chance to drive the car since I did the carb distrib cleaning but I don't have real high hopes that I have dealt with this problem yet. One thing that makes this even stranger, to me at least, is that when it first started happening (and remember this was before the electric pump came on the scene) it would only occur in the higher gears and when I was moving along pretty briskly. The 'low end', starting from a stop, did not seem to be effected.
Most recently though, like yesterday, the opposite has occurred and it is running in 3rd and 4th like a sled on snow but apparently starving for something, or shutting down cylinders in the low end when I am starting out in 1st or 2nd.

Any ideas, thoughts, scathing criticism would be most welcome,

Thanks much,
Jim Lee
 
Jim -

Just a stab in the dark, but since you've replaced the fuel pump, I wonder if your tank is vented well enough to allow the fuel to flow at the new rate. I just went through the ordeal of stopping the fuel in my TR3 from sloshing out on turns to the left, and closed off the overflow tube. Had to make sure my gas cap was properly vented, and thought maybe your problem may be similar.
 
No clue on your problem, but you should be wary of getting too enthusiastic with the emery cloth. (Doesn't sound like you were, 'tho) An old trick someone showed me years ago is to rub the rotor tip on a tire. Cleans it up nicely, with almost no abrasion. I suppose you could use an eraser if you wanted, but I always seem to have tires on the car....
 
That reminds me. Is it possible to get a distributor cap and rotor and spark plug wires from my friendly local auto parts store (TR3a 1959) or do I need to go to one of the Brit specialty places? I'm thinking that this original distributor was used on a lot of old British cars for a long time....D5...something?

Thanks again,
Jim Lee
 
Thanks for the reply Mickey. I'll check the gas cap for ventilation. Is there any other place, like inside the trunk on top of the gas tank, that needs to be ventilated? I've experienced this kind of problem on a motorcycle but in that case it actually shut down....exactly like running out of gas...until I got curious enough to open the gas cap and if my battery wasn't already shot try starting again. In this case I am still tootling down the road albeit with angry and resentful people passing me irregardless of uphill double yellow lines. It has yet to strand me but it's not a big confidence builder in my troubleshooting or mechanical abilities.

Jim Lee
 
At the top of the tank there is an overflow tube - connected to the filler neck collar - that runs over to the passenger side, and then through a hole in the body, next to that side of the tank. As I said, I crimped mine closed, but drilled out the rather small hole in the gas cap, in order to compensate. No problems, but I'm still using the mechanical pump, which I would imagine does not have the flow rate that yours might. Again, this may not be your problem - just a thought...
 
I guess an easy way to check would be to leave the cap open (assuming tank is not more than half-full or so), and driving to see if that clears the problem up.
 
Jim, I've had surprisingly good luck on maintenance parts (filters, points, caps, rotors etc) for my LBC's at the local NAPA. Granted my car is a lot newer, but many of these parts were common to several cars. It's certainly worth a call.
 
Jim,
We experienced a similar problem with our Ginetta a few years ago, she would start spluttering and coughing like she was only running on a couple of cylinders, it was REALLY bad going up hills, it felt like some kind of fuel starvation. We went through everything related to the fuel but found nothing. It turned out to be a worn coil which was overheating, changed it and have never had the problem since.

RG
 
A hopeful update!

Thanks for all the responses. Last night I made what I hope to be a huge discovery. Although I had been checking the Generator belt and it seemed tight enough I was shocked to find that the rear pivot bolt on my Generator was actually missing in action. Not only was it missing but this rear bracket was not even lined up because of the absent bolt. I had been wondering why I was having to recharge my battery so often but had sloughed it off to how infrequently I had been using the car and/or the age of the battery.

So my question to the group is how reasonable is it to suppose (hope and pray) that this most probably non-working generator could have been the cause of my sputtering and getting anemic, like barely limping along, after driving the car for like half an hour? Is it possible that if my battery/electric system was not being recharged that this could have had the 'running out of gas' feeling/effect after driving for a while? What I am hoping is that after xx minutes
without the generator doing its thing properly that the battery evantually would run down and finally get to the point where it wasn't providing enough energy for a normally running ignition system. So the 'running out of gas' effect was actually 'running out of spark', or at least healthy spark. As I recall I do not remember the car recovering during a given ride.
It would run beautifully for 20 or 30 minutes and then start to sputter and make me think the end was nigh. I would park it and the next day, or possibly even later that same day it would start up and repeat this cycle. I guess that I had given the poor old battery enough time to naturally recharge enough to run again for a while.

After replacing the missing bolt and getting the generator straight I was driving around last night
(with lights) and it ran like the champ that I know it to be for at least 20 minutes. No anemia, no 'I think I'm running out of gas' effect at all.

Anybody feel that I finally got lucky or....am I
grasping at electron straws? Time of course will tell. I'm getting my Black Beauty inspected tonight and the North Carolina weather is getting dryer and warmer so I will keep you all posted.
In any case it certainly cannot hurt to have a correctly mounted and working generator. If anybody with a TR3/4 could tell me what kind of voltage they measure at the battery at idle (I think mine is a little on the high side like 1000-1100 rpm) it would be much appreciated.

Thanks very much,
Jim Lee
1959 TR3a Black Beauty
 
What you found and described about the generator is exactly what happed in a car of mine. Drove 30 minutes into work head lights on and about 5 miles before getting there it started feeling spongy. Drove home from work lights on highway speeds and about 10 miles from home 45mph was as fast as I could go. The last 2-3 miles around 30mph and lights were getting dim. Had the alternator checked, it was dead. Replaced and off we go!

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Jim,
MOST cars tend to quit when they don't have enough juice. But I do believe you have an ignition problem. It sounds a lot like an overheating coil problem to be too. Try borrowing someone elses coil and replacing yours. It's worth a try.
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Latest update:
Thanks much for all the replys but I think that I am getting to the end of the saga. Unless I am terribly deceived my problem is a very wasted regulator contact point. In Section M (Electrical Equipment) on page 33 of my "Service Instruction Manual" Third Edition, Sixth Printing, figure 36 shows Control Box RB106-2.
The Regulator Moving Contact looked to be fused together with the opposing Fixed Contact with nasty looking burn marks all around. The fixed contact was like on a 45 degree angle instead of parallel to the other contact point and I didn't actually test but I doubt if there was any conductivity happening across the contact for quite some time. I was able to remove the moving contact and clean it up some but it is still pretty badly pitted. The moving contact I wasn't able to even loosen the locking nut to remove as it is some real soft brass and it is like welded on to the arm. I decided to clean it up the best I could with it still on there.

I am getting another regulator from Ebay that I won today so I am planning to first try just swapping the points and if that doesn't work out just swap the entire regulator. The rest of the control box looks fine and I have spent some time cleaning up the connections on the one I have so I'd rather keep that, especially if the one that I am getting doesn't have the screw in connectors. What I am curious about though is that the battery seems to be overcharged since I took it down to the auto store to have it tested. I was really hoping it was a bad battery but it was only a year and a half old and they put it in some super duper orgasmatronic contraption that not only tested it but put some fast 50 minute charge on it. When I got it home it measured 18 volts at the battery. When I disconnected the positive ground the car would stop running so it became obvious that it was running directly off the battery. What was interesting was I followed the procedure for testing the regulator and the generator by connecting the wires a1 to a and putting the volt meter on D and E on the control box (before I cleaned up the contacts) and the voltage showed a 3-4 and then would spike up very occasionaly and very quickly to like 14 or 15. After I cleaned up the contacts and now have a big gap there, instead of what I presume was a non-conductive fuse, it shows a much healthier voltage but the contacts never close and I don't see the moving arm actually move. What is wierd though is that I took it for a couple of 15 to 20 minute drives today and the battery voltage still measures at around 17 volts so maybe the regulator is doing its thing in NOT charging an overcharged battery. How it could have gotten this overcharged in only 50 minutes is amazing to me.

In any case my working theory as of now, and I will be sure to correct this if it turns out to be wrong is that the bad contacts on the regulator was forcing the car to run directly off the battery in addition I suppose to the missing screw on the generator bracket which may well have kept less tension on the belt which would satisfy my ignition demands for the first xx minutes of my rides but then as the battery wore down I would get the 'running out of juice' which I felt as 'running out of gas' symptoms as the battery wore down. Especially since daylight savings time and I have been driving around after work with lights and heater on.

I will keep you all posted.
Thanks very much.
Jim Lee
1959 TR3A
 
check hour ignition wires, I had the same thing happen to mine 59 TR3, Would loose power under a load, I replace the pump but it did not help, installed new sparkplugs the same, had just installed new ignition wires about 3 months ago, along with dist cap, rotor and points. I had the old wires and cap with me and installed them had no problems with old cap and wires. Installed new set of wires and have not had anymore problems with over 10,000 miles on them.
 
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