1985 Chevy Camaro

This could be one/more of several potential issues. With any hard-start, isolating the problem by following a logical sequence is necessary.

First, when was the last time you performed a tune-up/general maintenance? If it's been past the recommended service intervals, begin by replacing the dist. Cap/rotor (Check coil), spark plugs/wires, fuel/air filters. This will eliminate these components as potential causes.

Now check the quality of your spark as well as base timing and your timing advance as the engine progresses through the r.P.M.S. Compare to spec. If out of spec, do the necessary repairs and retest.

If the ignition system checks out, check fuel pressure and compare to spec. If your fuel pressure is out of spec, do the necessary repairs (fuel pump, pressure regulator, leaking injectors, etc.)

If your engine is injected, check that the injectors are firing and perform a cylinder balance test.

Next, check compression for each cylinder. If any one/more is significantly lower than spec, an engine overhaul may be in order.