Originally Posted by Frizlefrak

If they don't have a clue, they aren't "Corvette Mechanics". Probably janitors at high schools in San Bernadino. A 1991 Corvette is a simple OBD1 EFI system.

My real advice for a 19 year old making minimum wage is to sell the Corvette and buy a used econobox that runs correctly. When you've finished college, trade school, etc and have a decent paying job, then you can venture back into owning a sports car....but I digress. In the meantime....

1. Fuel pressure. Should be 38-44 psi at idle.
2. Base ignition timing. Set to 6 degrees BTDC.
3. Ensure plugs are fresh, gapped to .060. Cap, wires, rotor new.
4. Fuel filter new.
5. Check for vacuum leaks. You have EVERY symptom of a massive vacuum leak.
6. Noid light on all injectors to ensure they are firing

Start there, report back. Stop paying "mechanics" $100 an hour to guess at it and not fix it. Troubleshoot, don't guess.

They need three things, and three things only to run correctly:

1. Suitable compression.
2. Correct mixture of fuel and air.
3. Suitably strong spark delivered at the correct time.

That's it. If those three conditions are met, they run. If one or more is missing or deficient, they either don't run correctly or at all. Find what is deficient, correct the deficiency, and it will run.

I can't believe a "mechanic" can't diagnose 30 year old EFI technology....unless he's a stoned hippie janitor from Yucca Valley.