A 1985 Corvette may not start after warming up due to several potential issues, such as a failing ignition coil, a faulty crankshaft position sensor, or vapor lock in the fuel system. As the engine heats up, these components can malfunction, preventing the vehicle from starting. Additionally, problems with the fuel pump or fuel injectors may also become apparent only when the engine is warm. It’s advisable to check for error codes and conduct a thorough diagnostic to pinpoint the exact cause.
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2 screws.
yes
cracked heads or block
Could be a sign that the heater core is starting to leak
Often a knock when cold is caused by piston slap, which is pistons rocking in the cylinders until they expand in size when the engine warms up.
Does it quit shaking when it warms up? What engine and year of Aerostar?
Is it a lifter ticking?
Check for vacuum leaks.
crankshaft sensor
They are controlled by internal hydraulics so they will always 'free wheel'. As the engine warms up, the valving within the clutch actuates it. Sounds OK to me.
If its coming from your engine, you may need a valve adjustment..