We have been trying to fix this car for 2 years. Its started in the shop because we thought it had a cracked head. Turns out it was fine. Engine was timed and all solenoids were checked and the distributer was replaced. The car is no longer showing any codes and will cut off after it reaches 3000 RPM. There is not a check engine light or any other signals. Any ideas?

 

How are the two crank sensors?
Check that they are electrically fine and the pickups are clean of material.
It may be that at higher engine speeds the sensors lose resolution and causes the engine to cut out.
When the engine cuts out, what does the tach do? Does it immediately drop to zero or does it decrease speed with the engine?
If the same problem is persisting after the distributor/igniter/coil were replaced, then check the wiring of the ignition system. Look for loose, worn, broken, corroded wires/harness/connections.

Start at the basics.
Verify battery is fully charged and maintains a charge.
Verify battery terminals are clean.
Verify battery cables are clean and tight, with no corrosion.
Verify main grounds and bonding jumpers are attached properly, clean and tight.
Verify the ignition switch is not worn and loosing power.