The Stovebolt Site Forums The Shop Area Engine Shop weird starting problem

My 65 283 C-10 will start for months with no problems, and then all of a sudden, it will not start. I had trouble last christmas with it not starting, after several weeks of running great. One day I parked it, the next morning it would not start. After two weeks of trying, one morning it fired right up instantly. Now here it is July, and the same thing again. A week ago I drove about 40 miles, got home and parked it, next day, no go. Next two days, no go. Then the next day, fired right up instantly. Yesterday, started up fine, today, will not start. On the days that it starts, it will start all day. It is always the first start of the day that it fails, then it will not start the whole day. The engine turns over and it is getting gas. Thanks

Need to check if you have any spark, if not it could be a bad coil, but I would almost guarantee its a bad ignition switch or connection, or possibly neutral safety switch, try to start it in neutral rather then park when its acting up.
When it isn't working check the positive side of the coil for voltage when the key is turned on, no voltage, is a bad switch or wire.
Or it could be simply bad points if it isn't driven very often.
Good luck!

It is a 3 speed manual, so no neutral or park problems, has a HEI ignition. Thanks.

OK, just to be sure we're all on the same page- - - - - - -The engine cranks (starter turns the crankshaft), but the engine fails to run, right? When this happens, have you checked to see if the spark plugs are getting voltage? The simplest way to do this is tro pull a plug wire, and stick a spare spark plug into the end, then hold the plug shell against a ground (insulated pliers, please!) while somebody else cranks the engine. You should get a nice fat spark across the plug electrodes. If not, check the "Bat" wire going to the HEI cap to see if it's getting battery voltage during cranking. (should be 10.5 volts or more) If not, check the ignition switch for an open circuit during cranking. HEI systems put a big current load on the ignition switch contacts, and pre-HEI switches aren't designed to carry the load for very long. If you're getting good voltage to the HEI, you've got a choice of a bad module or a bad trigger coil. The wires fron the trigger coil to the module move all the time if the vacuum advance is working, and the wire strands can break inside the insulation and become intermittent, dropping the signal to the module periodically. The ignition switch is the most common cause of an intermittent no start condition.
Jerry

You are on the same page. I'll see if can figure out all the new info. Thanks.

I traced the wire from the HEI to the starter and found it to be in pretty sad shape, actually all the wires are needin' replacing. I found a loose ground on the starter also. I got no spark on the plug when I pulled the wire off and put in a spare plug the first time that I tried it, but after moving some wires around, tried again and the truck actually started running with the wire pulled off while I was doing the test! I've put off geting a new harness long enough, so now I gotta figure out which one to use. I am entertaining building my own harness,but I don't think that there is any one place to purchase everything separatley, such as the conections that attach the wires through the fire walls,the light sockets, and so forth. I need to replace everything, except I allready have a new steering harness. Thanks to all that responded and helped.

I replaced the wire from the starter to the HEI and I get 12v reading, I thought that was the problem but it still will not start. I'm still not getting any spark, so the only thing left would be the coil or module right? Joe

Are you still running through the resistance wire that was used on your points type dizzy or have you changed it out for a 12 gauge wire. On my 65 c10 with HEI I ran a 12 gauge wire from the fuse box on an unfused connector and just taped off the old resistance wire and the yellow wire to the starter. Hei needs 12 volts minumum to start and run.

It was the coil. My coil needed replacing. My volt meter shows 12 volts going to the HEI. I replaced my old yellow wire with a new wire, because the old one was frayed, are you saying that I need to re-route the new wire as you did? Thanks