i will give you my thoughts..
i dont like the 54psi of fuel pressure,,these should never have less than 60psi at all times..with that being said,it still shouldnt be leaning out if the pressure does rise to 60psi+ when in a pull,,if the pressure is holding 60psi+ in a pull and when cold,turning the starter,this rules out the pump out the pump,though the idle pressure is low..so,do make sure of the fuel pressure,the problem sounds familiar to a weak fuel pump.
sense the engine light did flash,this tells me it had a miss-fire,if you are satisfied with the fuel pressure,tune up the engine,replace the plugs,wires rotor and distributor cap,these plug wires and distributer caps will give a fit and there is no good way to test them..
a clogged catalyst converter will also cause a similar problem and will also make the engine light flash under load,sense the engine is really quiet,you may want to have a muffler
shop to test the catalyst converter
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