The Stovebolt Site Forums The Shop Area General Truck Talk '61 Warms Up, Won't Start

This just started in the last few days. My 61 Apache 10 with 235 6 starts and runs like a champ when cold. Once it warms up to operating temperature, it dies. It will restart, but only run a couple of seconds, then dies again. Let it cool off starts and runs good until it warms up. Put a fuel pump on ... no help. First thought it was starving for gas, now wonder if it's the coil or something else electrical. Any thoughts?

Sounds like a bad condenser!!!!!!!!!!

The ex's dad had a 60's model w/inline 6 and he had basicly the same prob, this has been a few years back but he said that it vapor-locked,dont know exactly how that works and dont know how to fix just my 2c

If it is a vapor lock, try putting a clothespin on the fuel line near where it goes into the carb. I don't know why it works, but it does.

All of the above are distinct possibilities. Vapor lock won't usually take effect until the engine is really warm; therefore, I'm betting either the condensor and or the coil. Putting the beast on the scope will show a breakdown in the height and/or the length of the firing line as it warms up. Or, if you don't have/don't want to spend the bucks (besides, how many of these kids nowadays can actually read and interpret a scope?), pulling the coil wire and holding it about a quarter inch from the manifold and cranking the engine, once it dies, will usually reveal the no-spark condition. Good luck with it!

I personally would spend $3.00 and replace the condenser first. Then take it from there.

I don't know how relevent this is with a Chevy, but when doing research on getting my father in laws '52 Dodge 1/2 ton running, I came across an intresting tidbit regarding warm fuel.

The placement of the fuel pump in the Dodge 230 is just below the exhaust manifold, and requires a heat sheild to protect the line going from the pump to the carb.. I guess when that line gets too hot, the fuel quits flowing.

If it still won't run with the gas cap off, and you've already replaced the condenser and eliminated other electrical potentials, the fuel line running to close to heat sources might be something to check.

My guess would be the coil also, if these are the only symtoms...

Check that your heat riser isn't shut closed also.

Its either the coil or condensor or both.had the same problem a couple times and it was coil both times.

I worked on a '32 Ford about 25 years ago with the same symptoms. There was junk floating in the gas tank. After it ran for a while, the crud would cover the pickup tube and kill the engine. After it sat for a little while, the crud would fall off the pickup and it would start and run again.

k10, I thought about that also. But didn't you mean to say stuck closed rather than shut closed?

Inky05, the clothespin is to insulate the fuel line to prevent heat from causing the fuel to turn to vapor. I really doubt if one clothespin would insulate the whole line. The farmers, in the 40s & 50s would put many clothespins on the fuel line to prevent vapor lock.

This is not a gas issue, it's a spark issue, and please stop with all the "vapor lock" nonsense. All my life I've heard about dreaded vapor lock but NEVER has it happened to me. It only complicates the diagnosis and solution. I agree with replacing the condenser. If that doesn't work, swap out the coil.

I'm With Inky05
It's the condensor, cheap fix . . . couple bucks. Done

Tab, you may the exception... VAPOR LOCK HAS HAPPENED!! When these old trucks were in 100 degree plus temperatures, the engine was a lot hotter and the fuel line was no more than 1 inch from the engine, thus causing vapor lock. Have you ever driven a 216 or 235 engine in 100 plus temperatures for eight plus hours a day? I have, when I was a young teenager on a farm... and they do VAPOR LOCK! Now, I am not saying this is the problem here, Phillip doesn't have the same conditions, a stuck heat riser could cause this also.

With the low octane fuels today, I doubt very much that it is a vapor lock problem. I do run my 235 very hard at time, even close to over heating it, but it never tried to vapor lock. It was rather common in the day but not much now days. I would also look for an ignition problem,
Scott

Phillip, take your pick or try all of the above. I hope we haven't totally confused you. I do hope you can come up with a remendy.

I'm With Inky05
It's the condensor, cheap fix . . . couple bucks. Done

Caroline's truck, don't let your alligator mouth overload you himminggbird a$$. There are a lot of variables here. Think about it, condesro maybe, or a lot of other things.

Inky05,
I wonder why the condenser would be heat sensitive? It works when cool, but fails when warm, then cools off and works again. Why?


Stuart.

I might be showing my age, but when we used to get vapor lock, we would put some ice on the fuel line going into the carburator, then figure it out later, Steve

Stuart,

I don't know why heat affects it, but it does. I once bought a really nice Audi Fox from a guy for $75 because he couldn't figure out this same problem. When I went to pick it up, I brought a new condenser with me. I installed it and drove away. I drove that car for years after that without a single problem.

Could be a plugged fuel filter and/or line. When it starts to die, choke it and see. If it acts like it wants to keep running,probably fuel problem. A coil/condensor will work when cool and when it heats up it will stop firing. I would be led to believe that if you were having a vapor lock problem, it would be after the vehicle has been run for a while(not just warmed up) in very hot outside temps. You're in Tejas, so it could be true. Vapor lock occurs when the gas boils and turns to vapor. Motor won't run on vapor. Easy way to check is to wet a towel and wrap it around the fuel line with tape before you start it. If it still dies after warmup, replace the coil and/or condensor.

If the coil and or codensor don't fix it check for a bad resister. These sometimes go bad overheat and quit.

For future reference Vapor lock is a pocket of hot vaporized fuel in the fuel line when this happens it creates enough pressure that the fuel pump cant overcome it,The easiest quick fix is to pour cold water over the fuel line and pump when it cools it will work.

not sayin either way,,but they will vapor lock,,vapor will compress and not flow...fuel wont compress...its hydraulics.. and they will vapor lock... another way to cure vapor lock is electric fuel pump....fixed mine...without a coil and condenser.....cuz...i knew it was vaporlockin...

Busy, busy day in the old garage one summer day--we were always slammed just before school started. It'd been like that all week, and we were seeing the light at the end of the tunnel (or is that the beer light in the bar window?). One of our long-time, good customers called and got the chief mechanic on the line. I walked up just as Tony, all sweaty and dirty, said to her "Tell you what, Nadine, I'll listen to the funny noise [your car is making]--put your car on the phone!"

Which, in a way, kindof highlights the difficulty of diagnosing a car on the internet (or on the phone!), and the frustration of the owner trying to follow this, that, and every other suggestion. We feel your pain, Phil. You may end up doing something that I was never all that good at, which is using a volt-ohm meter (in case the primary (power to the coil) and/or the secondary wire (coil wire) is breaking down under load/heat--this is also where the scope check comes in that I talked about.

A really good scope guy (or gal--seen one of two of 'em in my time) can look at the patterns and tell you a lot of stuff, including whether or not you have a potential fuel problem, though probably not a mechanical issue with the fuel system.

Having said all that (again), I'll reiterate this: I'm not very confident that there are that many people out in the repair world who can read a scope that well. Therefore, it gets down to, as some have said here, the basics. It needs fuel, it needs spark, and it needs compression. You have all three, initially, at least, and since only two of the three are going to go away with any immediacy, and then come back, we can safely rule out compression. When compression goes, it goes.

You need a couple of things on hand to begin diagnosing the problem: a continuity light, and a spray can of starter fluid. And maybe a flashlight, if you do this at night. A remote starter switch would be nice, but a helper will do, unless you're fast on your feet.

You need to remove the air cleaner (is it an oil bath, by the way), and go through your normal warm up of the engine.

As soon as it quits running, run around, throw up the hood, and check the following: the choke butterfly. I'm assuming it's a manual choke, but that doesn't mean it doesn't work its way closed, choking the life out of your engine.

If the choke isn't slammed shut, shake your starter fluid a couple times, and squirt a couple of quick squirts into the venturi of the carb. Try to start the beast. If it doesn't fire until the normal cool-down period has passed, the problem is almost certainly electrical. If it does try to go varoom! you're looking at a fuel delivery probem.

If it's electrical, never my strong suit, and you have at least a strong, orange, but optimally blue spark, and the spark goes away, the problem could be a broken power wire on either side of the coil. Remember, you need at least 9.6 volts for the thing to work (it is 12 volt system, right?). Some cars and trucks got their coil primary power from the starter; grease, oil, small furry animals, ham-handed mechanics, debris, could break a wire to where it works, but then doesn't work (heat, vibration, stuff).

It could be the primary wire from the distributor to the coil...the one that the points interrupt to induce the coil to spark. It's possible that the coil secondary (the thick one that goes to the center of the distributor cap) is broken, and heat causes a gap too great to bridge. This is where the ohm meter comes in.

Other possibilities include the distributor cap itself (cracks), the rotor bug (holes burned), though you usually see these with HEI more than with points. The coil itself is a major suspect, especially if the spark is less than optimal (blue). The points themselves, and the ground wire in the distributor should not be ruled out.

None of this stuff is long-haired thinking type stuff--just takes time and patience. That's enough for now. We can get to the fuel delivery stuff (most of which has been covered already) if the problem seems to you to be fuel-related.

Bluenwhite, thanks. This is an original truck, with most everything original to this truck so it does have oil bath filter, 12-volt system, + wire to coil from starter solenoid. Since this problem developed, it has a new fuel pump, points, plugs, condensor and coil ... at the rate I'm going it's not going to be that original for long! Will try your tips, along with the others I have gotten here until I get it going. Thanks to all for the suggestions.

I feel your pain, Phil. I wasn't always a mechanic, and okay, I'm no longer a mechanic, but I remember days and days of diagnosing by replacement, making desperate phone calls or visits in person to anyone and everyone, trying to coax any useful information out of anybody who seemed like they knew even a little bit about the inner workings of a car (or truck, as the case may be).

Some of those people included people whose job it was to fix cars for a living, so by providing me information, it was essentially taking money out of their own pocket...not that I had any money, mind you...but most people were kind, and somehow I survived. It's my way of paying that kindness back. Keep us posted.

It could very well be a vapor lock.you have gotten a lot of suggestions.Here is another one that happened to me years ago.A flexible gas line was closing after I drove the car for a while.It was between the gas tank and the fuel pump.The fuel pump sucking gas from the tank would cause the flexible line to collapse.Just a thought.