You might check the following: The fuel pressure regulator (1)
is a diaphragm-operated cartridge relief valve with the fuel
pump pressure on one side and the regulator spring pressure and
intake manifold vacuum on the other. A retainer (2) holds the
fuel pressure regulator. The regulator's function is to maintain
a constant pressure differential across the injectors at all
times. The pressure regulator compensates for engine load by
increasing the fuel pressure as engine vacuum drops. With the
ignition ON leaving the engine off (zero vacuum), the fuel
pressure at the pressure test connection should be 415-455 kPa
(6O-66 psi) . If the pressure is too low, poor performance could
result. If the pressure is too high, excessive odor may result.
The engine coolant temperature sensor is a thermistor (a
resistor which changes value based on temperature) mounted in
the engine coolant passage. Low coolant temperature produces a
high resistance 100,000 ohms at -40°C (-40°F) while high
temperature causes low resistance 7