QuestionMy rr has a new fuel pump that works great, and new plugs dist. cap rotor coil supressor ect... I get fuel to the injectors but not out of them, I get great spark and engine will run on carb cleaner sprayed into the breather. Is my problem the electronic fuel injection unit. prc6999 and if it is where is the cheapest place to get a good used replacement.
AnswerHi Chad,
here's a website I use for parts:
http://www.car-part.com
this part is found on 88 and 89 models.
Here's some info that may be of help:
DESCRIPTION
Hot Wire Multiport Fuel Injection
The ’Hot Wire’ Multiport fuel injection system derives its name from the mass air flow sensor which uses one cold wire and one electrically heated wire to measure the volume of air entering the engine.
The function of the system is to supply the exact amount of fuel directly into the intake manifold according to the prevailing engine operating conditions.
To monitor these conditions, various sensors are fitted to the engine to measure engine parameters. Data from the sensors is received by the Engine control module (ECM), the ECM will then determine the exact amount of fuel required at any condition.
The ECM having received data from the sensors produces pulses, the length of which will determine the simultaneous open time of each bank of injectors in turn, which will govern the amount of fuel injected.
Engine control module - ECM
The Multiport fuel injection system is controlled by the 14 CUX Engine Control Module comprising of a microprocessor with integrated circuits and components mounted on printed circuit boards. The ECM is connected to the main harness by a 40 pin plug.
Injectors
The eight fuel injectors are fitted between the pressurized fuel rail and inlet manifold. Each injector comprises a solenoid operated needle valve with a movable plunger rigidly attached to the nozzle valve. When the solenoid is energized the plunger is attracted off its seat and allows pressurized fuel into the intake manifold.
Engine coolant temperature sensor
The engine coolant temperature sensor is located in the front of the thermostat housing. The sensor provides engine coolant information to the ECM. The ECM increases the injector opening time when cold to provide improved driveability, and reduces the opening time as the engine reaches normal operating temperature.
Engine fuel temperature sensor
The engine fuel temperature sensor is located in the rail on the RH side of the ram housing. The sensor sends fuel temperature data to the ECM, the ECM on receiving the data will adjust the injector open time accordingly to produce good hot starting in high ambient temperatures.
Idle air control valve
The idle air control valve is screwed into a housing attached to the rear of the plenum chamber, between the plenum chamber and bulkhead. The idle air control valve has two windings which enable the motor to be energised in both directions thus opening or closing the air valve as required by the ECM. The idle air control valve will open and allow extra air into the plenum chamber to maintain engine idle speed when the engine is under increased (Electrical and Mechanical) loads. The idle air control valve will control engine idle speed when the vehicle is stationary.
Heated oxygen sensors (02 sensors) - Catalyst vehicles
The two heated oxygen sensors are located forward of the catalysts mounted in the exhaust downpipes. The sensors monitor the oxygen content of the exhaust gases and provide feedback information of the air/fuel ratio to the ECM. Each sensor is heated by an electrical element to improve its response time when the ignition is switched on.
Best of luck,
JohnMc
