1994 Chevrolet Camaro Car wont start

Start by measuring the battery voltage. It should be 12.6 volts. If you find closer to 12.2 volts, it's good but discharged. Charge it at a slow rate for an hour. If you find it's around 11 volts or less, it has a shorted cell and must be replaced. Jump-starting is usually ineffective with a bad battery.

If charging the battery gets the engine started, measure the battery voltage again with the engine running. It must be between 13.75 and 14.75 volts. If it is low, the charging system is not recharging the battery while you're driving.

What exactly are the symptoms? Do you get a single clunk from the starter solenoid? Does the starter crank the engine but too slowly? What happens to the brightness of the head lights or interior lights? Do you have a digital voltmeter so you can take some readings?

What about the head light brightness when trying to crank the engine? I need some details to know where to start the diagnosis.

You can get a perfectly fine digital voltmeter at Harbor Freight Tools for around seven or eight bucks.

You're going to need a mechanic to look at this. At "around 11 volts", the head lights should not dim very much. The industry-standard for the starter motor to crank the engine is 9.6 volts. You apparently have more than that. If the voltage is sufficient, slow cranking can only be caused by one open brush in the starter. That kills half the circuit. Current draw will appear to be close to normal, but actually, half of the starter is drawing double the current it should and the other half is drawing nothing. That makes voltages look normal but the starter has only half the strength it should have.

The clues you mentioned don't agree. The "Volts" gauge on the dash shows the battery voltage is much lower than 11 volts. The head lights should be dim during cranking indicating the battery has a shorted cell or a bad connection is restricting current flow. With a shorted cell, the battery will measure close to 11 volts when nothing is turned on. There's no cure for that other than to replace the battery. If the voltage is 12.6 volts but then drops a lot during cranking, that points to a bad connection. Most commonly on GMs with side post batteries, that is right at the battery, and much less likely at the starter.

Rats. You should be able to turn the crankshaft pulley by hand, but try with a ratchet and socket on the large center bolt head.