My 1987 5.7L has starting issues. I make sure the battery has over 12 volts before starting, it's usually @12.5-12.6 Volts. I turn on the key and the fuel pump makes it's prime sound. The engine turns over and over and doesn't start... then I turn off the key and let it sit for 3 min. and then it sometimes fires up and other times doesn't. When it does start, I put the voltmeter on the battery and it says 11.75-11.95 volts! It is the same coming out of the brand new delco alternator. This is at idle cause I didn't get another person to hold the petel down while I use the voltmeter. what should I have @ 2000 rpm's? I always thought 13-14 volts was good. I just bought the new alternator cause I put on the tester and it was pumping out closer to 18-19 volts. All battery connections are clean and tight. Good grounds from chasis to engine, firewall to engine, and engine to battery.
Total rebuild on engine: Started with an '86 TBI block and heads and put on '87 manifold top end putting new gaskets all over and new injectors that all test above 14 ohms. Also new HEI distributor, fuel pump from summit(tests at 37 psi while running) . New wiring harness and computer ending in ...165. Newer diehard battery. Once the ngine starts, it runs fine and after warming it up I rev it and it sounds great. It idles ok after I tested the tps and put it to 5.4 volts at idle. Never dies unless I drop the clutch and kill it, then I go to start it up again, it doesn't start until it cools down for 5 min. or so. HELP, this engine swap is turning out to be a real educational process, I can't figure this one out anymore, I need a master TPI person out there to get me on another path to figure this out. and get this '87 Lancrusier going down the road without breaking down or getting stuck after going into the store and coming out to it not starting. Need to check voltage to starter and cold start valve while cranking and fuel pressure while cranking...gotta get a buddy to help me out in the morning, Thurs. Is there something I am missing????? Maybe so simple I will kick my self in the *** when I figure it out???!!! HELP

 

first get your battery charged up, a fully charged 12V battery is 12.8V. start the car, with the fully charged battery the system voltage should be 13.8 to 14.2. more is better. If it's over 14.4 it has a problem.

who was running the tester when it made "closer to 18-19 volts"? must have bypassed the internal regulator, a good way to fry the alt.

voltage tests in the car running at some RPM or another are meanigless unless the battery is fully charged to start with. get it charged up and try again.