The Stovebolt Site Forums The Parking Lot '60-'66 Trucks 1963 intermittent starting problem

Need some help diagnosing a starting problem on my 1963 longbed. 350 SBC with RV cam, SM420 and an accel HEI distributor (coil has red and yellow wires). It normally starts and runs fine. Every once and while it will not start. Engine turns over strong, but no spark at the plugs. If I leave it sit for an hour or two or longer, it starts right up again.

The battery measures 12.68 volts. That's a bit low and I've noticed that the voltmeter drops to around 8.5 volts when cranking...is that enough to fire off the HEI? Is the battery the culprit or could the coil just randomly stop working and then start again? It has a new 140amp internally regulated alternator. Anything I should be checking there?

It has a full american autowire rewire that I just put in about 3 months ago. Not sure if the problem existed before that though because it was the first thing I did when I got the truck.

sorry for the lengthy set of questions...hoping that the collective wisdom will point me in the right direction

thanks,
Greg

Where is the coil mounted?

did you replace the resistor wire from the ignition switch to the coil. should be replaced with a non resisted wire so that it gets a full 12 volts when either starting or running. with a points ign it had 12v on start 9v on run
ron

Hei in the cap. Not external

thanks
Greg

thanks for the response. It's an HEI so the coil is in the cap. I replaced the 12 volt wire when I replaced all the wire and fusebox in the truck.

thanks,
Greg

I know that it is an hei because you said so before. you also installed a wiring kit; see i can read.was that wiring kit for a points ign or was it for an hei installation. they told you which wire to use right. didn't you also say that it was reading 9 volts through there on start so it must also must be running 9 volts while it is running. you may have wired it for an hei which is why it is starting and running on 9 volts as perhaps that wire is a resistor wire. I don't care where the coil is mounted, it is still an hei
ron

The wiring kits that I have seen don't include a resistor wire for the coil but many have undersized wire if an HEI is used. I believe that GM recommends a #10 wire for an HEI, most of the wiring kits provide a #16 wire. That may contribute to your problem but I don't believe it would cause a 3 volt drop.
Fred

I have the same kit on my 65. I run all msd ignition and it works fine. I know ive had the coil get too hot and cause a non start issue. I moved my ignition box from the fender to the glove box. and ive mounted the coil on the firewall by the brake master cylinder. what kind of hei are you running?

Load Test the battery, 8.3 is low for any elecronic ignition, how old is the battery? Next time it won,t start try a booster battery or jumper cables, that should help narrowing it down.

HEI module going intermittent with heat???
Scott

Check your ignition switch. As stated earlier it switches to 12 volts during cranking and 9v during running - but with a bad / intermitant ignition switch you could be getting 0 volts during cranking and 9 with the key in the run position. So you need to check voltage at the distributor DURING the cranking when it is not starting - cause if it's intermitant like you say, you'll only find it when it's not working.

Folks, thanks for all the ideas. Since the switch tested good, it seems either the coil or the module was the culprit. Replacing both would have cost more than a new, from summit racing, distributor so I went that route. No problems since.

thanks again
Greg