Topic: '36 Ford, hard to start when hot


32hoke    -- 07-29-2010 @ 5:52 PM
  When the car is cool it will start right up and run just fine. However, when I stop after a 15-20 mile drive and try to start the car again while it is still operating temperature it doesn't want to start. If I wait a while and let it cool down it will crank right up again and be fine. The car has Skip water pumps and a Skip coil and runs about 180-190 even in a Texas hot summer and in traffic. Just going down the road it will run about 160-170. I have thought about adding an electric fuel pump (6 volt) since I suspect vapor lock, but I'm sure open to suggestions. I have the pump, just haven't installed it yet. I'd appreciate your comments. Thanks


dansford    -- 07-30-2010 @ 3:17 AM
  I would contact Skip.


TomO    -- 07-30-2010 @ 7:29 AM
  I would spend a little time doing diagnosis before installing an electric fuel pump.

When the car is in failure mode, remove the air cleaner and look into the throat of the carburetor. Operate the accelerator one time and see if you get 2 squirts of gas. If you do, you have gas in the bowl.

Next check the spark by holding a spark plug wire near a head bolt, (you can use a small screwdriver with an insulated handle or a fuse puller to eliminate the shock hazard), the spark should be at least 1/4 inch long and blue in color. Weak spark can be caused by bad condenser, weak coil, low voltage to the coil or insufficient dwell of the points.

If you have a gas supply and a good spark, your engine may be flooded from a leak in the carburetor power valve gasket. Try flooring the gas pedal while cranking the engine to start it. Check for flooding by removing all of the plugs and examining them for signs of gas.

Tom


supereal    -- 07-30-2010 @ 8:41 AM
  When you say "doesn't want to start", do you mean it cranks fine, but doesn't fire, or won't crank fast enough to start?


32hoke    -- 07-30-2010 @ 11:06 AM
  Tom, thanks for your suggestions. I'll do those checkws. Super, when the car is hot it will crank fine but not fire. The last time I had the problem I was in town by the court house and I used a 12 volt truck to get me started. The starter spun faster and it started pretty quick and I quickly removed the jumpers from the battery. I started the car in the garage a couple of days ago to move it around. It only ran a minute or so. When I was ready to put the car back in place--maybe 5 minutes later--it started right up. The engine is very quiet and smooth when running.


supereal    -- 07-30-2010 @ 12:14 PM
  Just today, we repaired a car with the same problem. We found that one of the point sets in the distributor was misaligned (the "make" set) and the contact area was very small. This prevented the coil from being fully charged, relying on the "break" set only, and kept the car from starting. Whomever installed the points didn't take time to align them properly. You should get a strong blue spark when you hold a plug wire near the head while you crank. This owner of this car said there was a weak "white" spark. That told us where to look. New points, properly aligned, and a trip to the Sun machine to set it up solved his problem.


32hoke    -- 07-30-2010 @ 12:55 PM
  Thanks Super. Do this problem take place even when the car is cool? This car ALWAYS starts easily and quickly when it is cool. It's when the car is warm that I have the problem. I sure do appreciate your patience. Thanks


supereal    -- 07-30-2010 @ 3:54 PM
  When the engine is cold, clearances are looser, allowing faster cranking. More important, when the starter motor is hot, either from running, or from the exhaust manifold, the resistance goes up, and it requires more power to do its job. This can rob the ignition of enough voltage to feed the coil. If the coil is old, and gets hot, they ALL fail to produce adequate spark, and need to be rebuilt or replaced. We often install an auxiliary circuit to provide extra voltage to the coil to aid hot starting. If anyone is interested, I'll describe it again. As for patience, I'm well stocked, as I raised three kids and made it thru the teen years (my youngest is now 51!). On this Forum, there are NO dumb questions, although some of the answers are suspect!


tbirdhandyman    -- 07-30-2010 @ 7:28 PM
  Hi John, I used to have your problem with my '41 Mercury. It would run okay for hours until I stopped for gas. Most times we would have to push it to restart the engine (abouut 10 feet). I installed a spring-loaded push button switch under the starter button that I would push in while cranking the engine. This is connected across the ign. resistor on the firewall & puts full battery voltage on your coil. There are no extra wires in the engine compartment. This has worked for years on my 6 volt car. Robert E.


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