How low of an input voltage will an HEI setup tolerate? And what would be the immediate effects of a voltage dropping below that threshold? On my engine, it appears that my alternator is not doing very well anymore and at idle, the voltage drops to right around 12 volts. I have an HEI setup and at idle it has misfire. But when I rev up the motor and the voltage Rises back up around 13 to 14, it runs good. So I'm trying to determine if it might be a voltage shortage to the HEI before I start tearing into it and look for fuel supply issues or something else.
engines with HEI will start when cranking, and the battery voltage is usually around 8-10 volts? Misfiring seems to be the result of running low on power at higher rpm, though. When cranking, there's lots of time for the system to "charge" between firings, not so at higher RPM.
HEI Distributor Troubleshooting With Performance Distributors (chevyhardcore.com) Well, I think Hotrodjohn71 you need to ask yourself, if you're going to ask the doctor over the phone about your condition with hopes of getting a solid response that proves beneficial, you might want to give as much back history as possible to cure the condition not just treat the symptoms. I think it's a fuel pump issue.
I doubt that is the problem. If you want to make sure, just hook up a battery charger while the engine is idling and see if that changes anything.
Ahhhh …. Maybe . But probably no . Vacuum leaks ? Age of tune up ? Fuel filter ? Stuck / sticking vacuum advance / fly weights ? Bad ground or wiring ? Coil ? Carb ? Fuel pressure ? Lager or ale ? Could be a multitude of things , easy to check th off the list . Even easier to point the parts canon at it and blow some dough on a simple fix . I spent a day checking stuff on my ford 302 for a no start , ended up being a missing spring clip on the distributor .!! Point is don’t overlook anything , no matter how stupid you may think it is .
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