| jeff holland | -- 06-08-2010 @ 9:48 AM |
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Thanks for the many suggestions. Responses seem to revolve around electrical issues when restarting after the engine is hot. The engine runs fine. When restarting the starter kicks in and with some playing with the accelerator and letting the new fuel pump run a bit it does eventually start. Being that the car is still 6v. I note the voltage seems to drop off due to cranking. I have replaced the coil, put in new battery and did change battery cables. I was not aware of the need for specific cable rating. I bought what looked like a replacement at my local Napa store. I'll check with Vintage Ford for correct cables. My mechanic said the fuel pressure at the carb. is set for I believe 2.5 lbs. Thanks for your help. Jeff Holland
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| 37RAGTOPMAN | -- 06-08-2010 @ 4:23 PM |
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I was unaware about the electric fuel pump, were do you have it hooked up to, is it on the ignition switch? LET US KNOW, the more you explain the easier it will , KEEP ON TRUCKIN 37 RAGTOPMAN
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| supereal | -- 06-13-2010 @ 1:04 PM |
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Jeff: I, too, suspect that you have undersized cables. Some being sold as 6 volt cables have lots of insulation, but insufficient conductors. When almost all components get hot, the resistance goes up. That reduces current (Ohm's Law). The starter motor is hot, too, much of it from radiation from the exhaust manifold, and further saps the system, leaving little to saturate the ignition coil. A trick to raise coil supply is to connect a wire from the starter motor side of the solenoid to the coil input terminal, with a diode in that wire to act as a electrical "check valve". Obtain a diode from a place such as Radio Shack, and ask for one with the highest rating. To be sure the diode is "facing" the correct direction, check the bypass wire with a voltmeter by connecting the (-) lead to the wire, and the (+) lead to ground. If, when you press the starter button and you see about 6 volts, it is OK. If not, reverse the wire (or the diode) and check again. The purpose of this wire is to place full battery to the coil as long as the starter is activated, then allow the regular source to take over. The diode is necessary to prevent the bypass from trying to run the starter when the button is released. This system was used in some modern 6 volt cars as a built in way to aid hot starting. Be aware that this bypass will allow the engine to run as long as the starter button is pressed, even without the ignition being switched on. This bypass is particularly helpful on well worn engines.
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| ford38v8 | -- 06-13-2010 @ 3:05 PM |
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Bob, You've posted this bypass with diode before, but this explanation and instruction is better! The item of particular interest, though, is the power to the coil with the starter button, which must be disconnected for various test operations using the starter. Can you design an alternative connection to bypass the resistor but is operative only through the ignition switch? Alan
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| supereal | -- 06-14-2010 @ 8:17 AM |
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Thanks,Alan. We have made up quite a few of these "hot wires" over the years. The trick is to confine the energization of the coil only to the times the solenoid is running the starter, of course, It could be "fail safed" by inserting a relay on either side of the diode, with the relay pulled only when the ignition switch is on. This tends to make the circuit somewhat more complicated than would seem practical. If it is frequently necessary to run the starter without feeding the coil, it would be less trouble to just put a manual switch in the bypass wire to disconnect it, or just pull the wire off the coil, perhaps using a simple spade connector. So far, it hasn't been a problem, but I can see your point.
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