61' Scout, Starts and immediately dies... It ran fine yesterday!

Hi All,
I have a 1961 International Scout 80. I picked it up about a month ago and have been working on it ever since. It has been running a little rough but ok. Carb definitely could use at least a cleaning.
Recent history is as follows…
Brought home a month ago.
replaced clutch hydraulics and rebuilt rear brakes 3 weeks ago
Began rewiring 2 weeks ago including removing dash, choke and throttle cables
Completed rewiring of engine and lights and most of dash. Some wires are still left open.
Since replacing the clutch hydraulics I have been starting it up every few days to drive from a parking space, about 100 ft, to the garage.
2 days ago after finishing working for the night I drove and parked it. The next morning it will not run. It starts and then immediately dies.
I know there is a number of things it could be I just don’t know the best way to go about diagnosing the issue.

Check for voltage at the coil (+) terminal. If you crank the engine over and hear it ‘catch’ as though it is running and release the key only to hear the engine is dead you may have burned out the resistor used to drop running voltage to the coil below 8 volts. The reisitor looks like this


and it is likely mounted on the firewall. With the key in the RUN position test the coil (+) and if no current is there check both ends of that resistor and if voltage is at one end and not the other it is your problem.

Make sure you treat all the gas you use with an ethanol gas stabilzer or treatment. I’d get a product for marine motors. This motor and the fuel system will not tolerate the ethanol that is in our gas. Your problems could be an ethanol fuel related. The rubber fuel lines get soft, gummy, and sluff off material. The carb will have problems too. If you can find ethanol free gas in your area, use it in your old truck.

Thanks guys. 2 things I hadnt even thought of! I get out the multimeter and check the coil tonight…

If power is present at the coil in both the RUN and START positions you need to consider a contact point problem or a problem with the carburetion.

Does gas squirt out into the carb after it dies? Take off the air cleaner and look down the carb as you operate the throttle.

So upon closer inspection I’ve discovered that the resistor had a jumper basically bypassing the resistor… I did not get out the multimeter yet but is it safe to say that is where things went wrong? Is it probable that I’ve fried the coil?
I’m thinking the PO didn’t feel like replacing the resistor just to show it would start while trying to sell it… I’ve been running it on and off at idle for a month like that…

The points and condensor may be toasted. But replace the resistor and get the wiring reconnected properly and check for spark output by removing the coil wire from the cap and holding the end near the engine while opening and closing the point gap. Secondary output occurs when the points open.

It may be necessary to depress the bas pedal once to set the choke before starting. Check to make sure the choke is in the closed position before attempting to start, then monitor choke position my 2 cents.

Those early Scouts were as basic as International farm tractors @Barkydog. They all had manual chokes and manual transmissions. And their engines were peculiar as they were 1/2 of a V-8. International cast the right bank of their 390 and 304 engines to make 4 cylinders for that Scout. The distributor cap was the same as the V-8 with every other plug wire outlet capped. I don’t recall there being any options offered beyond the heater and radio and a choice of SUV cab or a 1/2 cab mini pickup. They were somewhat popular here in the 60s and still have a cult following here. But without power steering or power brakes they were not for the faint at heart.

Thanks everybody. So yesterday evening I ran through some things and here is what I found. I know good fuel is getting to the carburetor and power is getting to the coil.
I pulled the plugs and they had a fair amount of carbon buildup with orange spark. I wired it back up to put the resistor back in line. It was running a little rough before this so I decided to pull the carburetor to rebuild.
Once I get the rebuild kit (EtOH resistant) I’ll put the carb back in, replace the plugs and give it a try. Next step will be to run through the rest of the ignition system and make sure the coil, rotor, points and condenser are good.
In case anyone is interested I’ll come back after the weekend and follow up.

Jumping the resistor will ALWAYS burn the points. You have a 12 volt wire going from the start position on your ignition switch to give a hot spark to start the car and another 12 volt wire between the run position of the switch and the ballast resistor and a 6 volt feed for the coil and points to run on when you are driving.

Check to see if your points have welded themselves together. That will absolutely and instantly stop it from starting.

If all else fails blow back through the gas line and make sure the distributor isnt worn out.

well I I have a 75 ford pick up and about two years ago the ethanol finally caught up with it .

over the period of about a year, the fuel lines started to get soft and gummy and leak, as mentioned above. then after I had replaced them, the carb final gave out, when my son helped me rebuild it, I was amazed that it ran as long as it did. everything inside it was deteriorated to the point where some things had completely dissolved.

the modern re build kits have more ethanol tolerant materials.

make sureyou get all the diaphrams too, as they don t always come with the kit or get replaced.

for your current prob I d check the accelerator pump diaphragm on your carb, if the other stuff doesn t fix the prob

Good advice for older vehicles by @wesw above. When my older Ford truck exhibits this symptom it is usually caused by a problematic inlet valve on the carburetor. It gets gummed up and starts sticking when not driven often. So I think you carb rebuild idea is a good one.

Oh, and a 61 Scout not starting every time, that’s probably not that unusual. Think of it as a feature. lol …

I can tell you , too, that if my son wasn t there to help me with the carb rebuild, I would have been lost and not known what all the parts were.

if I need another old carb re build I ll try to get one that s been rebuilt already or a new one to save hassle.

Anyone remember when oil companys started mixing ethanol with gas? I have a 82 dodge pu 318 that runs hit & miss. wandering if ethanol is messing with carb.

MTBE phase-out started in 2003. It was replaced by ethanol as an octane enhancer.

If the coil was being fed 12 volts for any length of time you could have fried it…the points too.