Thread: Dies after appox 10 min

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Have sbc 400 engine in a 1954 car. Car starts fine when first start will run for appox 10 min then dies, Let set for about 2 min will restart and run for about 3 min then dies.
Alternator shows 15 amp on guage .
Alternator is wired directly to battery and has a grounding strap to frame.
Could the 15 amp charging rate be causing the distributor module to overheat and shut the engine off.
The alternator has a constant charge rate of 15 amp even with the lights and a/c on.

It sounds like your amp meter may be installed incorrectly? it needs to be between the output of the alternator and positive side of the battery (see AutoMeter instructions below). Make sure that you're wired correctly. Amp gauge should hang just above zero after initial start up and bounce down and back up when lights or another accessory is turned on. It shouldn't stay at 15.

That said, you may also be chasing a fuel problem, i.e., fuel lines too close to heat source and inducing a vapor lock. The two minute "cool down" allows enough fuel to return to the lines and the float bowl. Are your fuel lines well away from exhaust and not tight to the engine block?

I think you are chasing two problems.

Put a good quality voltage meter from battery ground to alternator output terminal, see what it is really doing.

I expect your guage is a volts guage, not amps. Very different things, please verify.

If it is volts, and truly reads 15, that's too high.

What ignition system do you have? I suspect a bad module in your HEI.

A quick way to figure this one out would be to unwire the alternator. Simply remove the plug from the regulator and start it up... let it run!
If it dies at 10 minutes... it isn't your charging system. I suspect you do have a volt meter, not an amp meter. In any event, stop the alternator from charging and let it run,
Let us know what it does.

My first thought too was that you've got a volt meter, not amps (typical Volt meter scale is 8 to 18, ammeter -30 to 0 to +30) and I suspect the problem is in the ignition module, not related to your charging system. Mike (34_40) has a good suggestion that will tell you for sure.

more info needed . is the tank orig ? tank sock could be clogged up . sounds like fuel problem . i think if overcharging it would burn out the module . as stated, unhook the alt and run it .

Many moons ago I had a 57 Bel-Air with the same problem except I was running a points distributor with 2-4's. As shine suggested it was a clogged tank. Once I got it cleaned out, no more problems.

i once bought a 57 ht dirt cheap . the guy had spent time and money replacing parts but never got it dependable . i pulled the sending unit out and there was an inch or so of crud in the tank . it would starve for fuel and die . cleaned it out and it ran fine .

Sure would be nice if guys would come back and close the loop. And BTW I'd say Shine's likely right on the fuel supply..... but we may never know for sure.