Fuel Injection System - Multi-Point Ford LTD Crown Victoria I

COMPONENT TESTING

Note. Specific component testing information not available. Refer to any tests performed during REMOVAL & INSTALLATION or OVERHAUL procedures

DESCRIPTION

The Electronic Fuel Injection (EFI) system is a pulse time, multi-point system using either mass airflow or speed density control to meter fuel demand. Mass airflow system on 1.9L EFI, 2.3L EFI/Turbo and 3.0L EFI engines uses input from mass airflow system with integral air temperature sensor to compute fuel needs.

Speed density control system on 2.3L EFI and 5.0L Sequential Electronic Fuel Injection (SEFI) engines uses input from various sensors to compute fuel needs. On-board Electronic Engine Control (EEC-IV) system has Electronic Control Assembly (ECA) which receives inputs from various engine and vehicle sensors to compute required fuel flow rate necessary to maintain prescribed air/fuel ratio throughout entire engine operational range.

ECA then outputs command to energize fuel injectors and meter precise quantities of fuel into intake ports. Injectors are energized for exact length of time which is the only controlled variable in fuel delivery system.

Scheme 13

FUEL SUPPLY OPERATION

Fuel supply is provided by chassis mounted or in-tank electric fuel pump. Some models also use one in-tank low pressure pump and one externally mounted high pressure pump. Pump delivers fuel from fuel tank through 20-micron fuel filter to fuel charging manifold assembly.

Fuel charging manifold assembly incorporates electrically actuated fuel injectors directly above each intake port. Injectors spray metered quantity of fuel into intake air. Constant fuel pressure drop is maintained across injector nozzles by pressure regulator.

Fuel pressure regulator is connected in series with fuel injectors and is positioned downstream from them. Excess fuel supplied by pump, but not needed by engine, passes through regulator and returns to fuel tank through fuel return line.

On 1.9L, 2.3L, and 2.3L Turbo engines, all injectors are energized simultaneously, once every crankshaft revolution. On 3.0L engine, injectors are energized in 2 groups of 3 with each group of 3 being energized every other crankshaft revolution. On 5.0L engine with SEFI, all injectors are energized once every crankshaft revolution. Each injector is energized in same sequence as ignition firing order.

ECA determines required fuel flow rate necessary to maintain prescribed air/fuel ratio for given engine operation by measuring quantity of air entering engine. Computer determines needed injector pulse width (period of time that injectors are energized) and energizes injector to meter exact quantity of fuel.

Mass airflow system measures intake air quantity and quality with vane airflow meter and its integral air temperature sensor. Speed/density control system uses Throttle Position Sensor (TPS), Throttle Angle Rate (TAR) sensor, Manifold Absolute Pressure (MAP) sensor and Air Charge Temperature (ACT) sensor to determine intake air quantity and quality.

Scheme 14

FUEL INJECTORS OPERATION

Fuel injector nozzles are solenoid operated valves which both meter and atomize fuel delivered to engine. Injectors are mounted in lower intake manifold with their tips directing fuel just ahead of engine intake valves.

Injector bodies consist of solenoid actuated pintle and needle valve assembly. Electrical control signal from ECA unit activates injector solenoid, causing pintle to move inward off seat, allowing fuel to flow.

Since injector flow orifice is fixed and fuel pressure drop across injector tip is constant, fuel flow to engine is regulated by how long solenoid is energized. This length of time is known as "pulse width". Atomization is obtained by contouring pintle at point where fuel separates.

Scheme 15

FUEL PRESSURE REGULATOR OPERATION

Fuel pressure regulator is attached to fuel supply manifold assembly downstream of fuel injectors. It regulates fuel pressure supplied to injectors. Regulator is diaphragm operated relief valve in which one side of diaphragm senses fuel pressure and other side is subjected to intake manifold pressure.

Nominal fuel pressure is established by spring preload applied to diaphragm. Balancing one side of diaphragm with manifold pressure maintains constant fuel pressure drop across injectors. Excess fuel is by-passed through regulator and returned to fuel tank.

Scheme 16

AIR VANE METER ASSEMBLY OPERATION - 1.9L & 2.3L TURBO

Air vane meter assembly contains 2 sensors, vane airflow (VAF) meter and vane air temperature (VAT) sensor. VAT measures temperature of incoming air.

VAF measures volume of air entering engine. Airflow moves vane which is mounted on pivot pin. Vane is connected to variable resistor (potentiometer). Output of potentiometer, which is connected to 5-volt reference signal from ECA, varies with volume of air flowing though meter.

Intake air volume and temperature inputs are used by ECA to compute fuel flow necessary for optimum air/fuel ratio.

MAP & ACT SENSORS OPERATION - 2.3L, 3.0L & 5.0L

Manifold Absolute Pressure (MAP) sensor compares manifold vacuum and manifold pressures to obtain manifold absolute pressures. Resulting input signal from sensor provides ECA with engine load and air density information. This sensor is located on firewall in engine compartment or on air cleaner.

Air Charge Temperature (ACT) sensor measures air/fuel mixture temperature. Resulting input signal from sensor provides ECA with density correction factor, which is used to calculate airflow and to proportion cold enrichment fuel flow. This sensor is located in side of throttle body on 2.3L and 3.0L models. On 5.0L models sensor is located in air cleaner.

FUEL SUPPLY MANIFOLD ASSEMBLY OPERATION

Fuel supply manifold assembly (fuel rail) delivers high pressure fuel from vehicle fuel supply line to fuel injectors. Fuel rail consists of tubular rail or stamping with injector connectors. Fuel pressure regulator is mounted on flange attached to rail. Rail also has mounting attachments which locate and secure fuel injectors in intake manifold.

AIR THROTTLE BODY ASSEMBLY OPERATION

Throttle body assembly controls airflow to engine through butterfly valve. Throttle position is controlled by either linkage or cable/cam mechanism. Body is one-piece aluminum die casting with single bore and air by-pass channel.

Air by-pass channel carries idle airflow which is regulated by air by-pass valve. Air by-pass valve is used by ECA to adjust both cold and warm idle speeds. Air by-pass valve uses solenoid valve to vary volume of idle airflow allowed to enter by-pass channel.

AIR INTAKE SYSTEM OPERATION

Air intake system on 3.0L engine incorporates throttle body and intake manifold in one-piece unit. All other engines use 2-piece (upper and lower) intake manifolds. Runner lengths are tuned for optimum engine torque output. Manifold provides mounting flanges for throttle body assembly, fuel supply manifold, accelerator controls, EGR valve and supply tube.

Vacuum taps are provided to support various engine accessories. Pockets for fuel injectors are machined to prevent both air and fuel leakage. Pockets in which injectors are mounted are placed so injectors spray fuel directly in front of each intake valve.

FUEL PUMP CONTROL OPERATION

When ignition switch is turned to "ON" position, EEC power relay is energized (contacts closed). Power is provided to fuel pump relay and to timing device in ECA. Fuel pump receives power through fuel pump relay contacts. If ignition switch is not turned to "START" position, timing device in ECA will open ground circuit after approximately one second. ECC senses engine speed and shuts off fuel pump by opening ground circuit to fuel pump relay when engine stops, or when engine drops below 120 RPM.

Opening ground circuit de-energizes fuel pump relay (contacts opened) and de-energizes fuel pump. This function allows pressurization of fuel system. When ignition switch is turned to "START" position, ECA operates fuel pump relay to provide fuel for starting engine while cranking.

INERTIA SWITCH OPERATION

In event of collision, electrical contacts in inertia switch will open. This will automatically shut off fuel pump. Fuel pump will shut off even if engine does not stop running. Engine will stop shortly due to lack of fuel. It will not be possible to restart engine until inertia switch is manually reset. To reset inertia switch, depress button on top of switch.

Inertia switch is located in trunk on left hinge support on Town Car, Crown Victoria, Grand Marquis, Thunderbird, Cougar, Mark VII/Continental, and Mustang 2-door models. On Crown Victoria and Grand Marquis station wagon models, switch is located in left rear side storage compartment. It is located near left taillight on 3-door Mustang. On Taurus and Sable sedan models, switch is located behind trim panel in left side of trunk. On Taurus and Sable station wagon models, switch is located behind access door in right rear cargo area.

Scheme 17

TROUBLE SHOOTING PRELIMINARY CHECKS

Following systems and components must be in good condition and operating properly before beginning diagnosis of fuel injection system

1. Battery condition
2. State of tune
3. Fuel delivery system
4. All wiring and vacuum connections
5. Air cleaner and ducting
6. Cooling system

Note. Some vehicles may not include all components listed in this section.

ENGINE DOES NOT CRANK

Check for starting and charging system problems.

ENGINE CRANKS BUT DOES NOT START

1. Ensure fuel tank contains adequate amount of fuel. DO NOT assume that fuel gauge is correct. Check fuel for dirt, water or other contamination.
2. Check ignition system for strong secondary current at spark plugs. If none exists or if current is weak, repair ignition system problem before continuing with fuel injection diagnosis.
3. Check fuel lines and fittings for leaks. If no leaks are found, check fuel delivery system for proper operation, pressure and volume.
4. Check if inertia switch is tripped and reset if necessary. Check for defective injector, TPS stuck at WOT or bad coolant temperature switch.

HARD TO START - COLD

Inoperative ISC motor. EEC-IV diagnosis required. TP sensor stuck at wide open throttle (WOT), or inoperative injector. Crank engine with TP sensor disconnected. Check for injector discharge at injector.

ROUGH IDLE - COLD

Injector leaking or inoperative. Check operation of injector. Injector "O" ring seal leaking. Perform injector/regulator leakage test. Check for possible vacuum leak.

STALL, STUMBLE, HESITATION - HOT OR COLD

TP sensor failure. EEC-IV diagnosis required.

HARD START - HOT

1. Inoperative ISC motor. EEC-IV diagnosis required. TP sensor stuck at WOT. EEC-IV diagnosis required. Injector leaking or inoperative. Check for fuel charge while cranking engine.
2. Excessive fuel pressure. Service pressure regulator and fuel return line. Contaminated fuel pressure regulator valve and seat. Service pressure regulator or check fuel pressure bleed down after engine has been turned off. Injector "O" ring seal leaking. Perform injector leakage test.

ROUGH IDLE - HOT

Injector leaking or inoperative. Check operation of injector. Injector "O" ring leaking. Perform injector leakage test.

STALLS ON DECELERATION/QUICK STOP

ISC inoperative. EEC-IV diagnosis required.

LACK OF POWER

Fuel filter may be clogged. Check fuel delivery and repair as needed.

REDUCED TOP SPEED/POWER

Plugged injectors. Check injector discharge at injector. Damaged fuel pressure regulator. Service or replace as necessary.

SURGES AT CRUISE

Plugged or leaking injectors. Check injector operation. Check also for restricted fuel filter.

Scheme 18

FUEL DELIVERY SYSTEM TEST - 1.9L

1. Check fuel tank for adequate fuel supply. Check for fuel leakage at all fittings and lines. Using volt-ohmmeter (VOM), check fuel pump electrical circuit for voltage supply and continuity. Disconnect harness connector just forward of fuel pump inlet. Connect VOM to body wiring harness connector. Turn ignition on while watching VOM.
2. VOM reading should rise to 10 volts or more then return to zero volts after approximately one second. If not as specified, check inertia switch and electrical system. Check fuel pump continuity. Connect VOM to pump wiring harness connector. If there is no continuity, check directly at pump terminals. If no continuity at pump terminals, replace pump. If there is continuity shown at pump terminals, service or replace wiring harness.
3. Check fuel delivery volume. Disconnect return line at fuel rail, being careful to avoid spilling fuel. Connect hose from fuel rail fitting to calibrated container of at least one quart. Connect Fuel Pressure Gauge (T80L-9974-A) to fuel diagnostic valve on fuel rail.
4. Remove fuel pump relay, located on left side of dashboard. Install modified fuel pump relay. Run extended ground lead from modified relay to convenient point. Activate fuel pump for 10 seconds by grounding extended ground lead from relay. Observe pressure on gauge. If there is no pressure, check voltage supply from relay through inertia switch to fuel pump. Repair as necessary.
5. Check delivery volume after all fuel has drained from hose into container. Fuel pump is operating properly if fuel pressure reaches 35-45 psi (2.5-3.2 kg/cm 2 ), delivery volume is minimum of 5.6 ozs. (.17L) for 10 seconds, and residual pressure holds at minimum of 30 psi (.211 kg/cm 2 ) immediately after pump is shut off.
6. If all 3 conditions are met, fuel pump is operating normally. Check for engine and electrical problems. If pressure is good but volume is not, check for restricted filters or supply lines. After correcting any blockage, recheck. If volume requirements are still not met, replace fuel pump.
7. If both delivery pressure and volume requirements are met, but residual pressure does not hold, check for leaking regulator or injectors. If both test good, replace fuel pump/sending unit. If no flow or pressure is seen, fuel system should be checked as in step 6). If no trouble is found, replace fuel pump/sending unit.

FUEL DELIVERY SYSTEM TEST - 2.3/3.0/5.0L & 2.3L TURBO

1. Check fuel tank for sufficient fuel supply. Check for fuel leakage at all fittings and lines. Using volt-ohmmeter (VOM), check fuel pump electrical circuit for voltage supply and continuity.
2. On Town Car, Crown Victoria and Grand Marquis models, disconnect fuel pump electrical connector just forward of fuel tank. On Mark VII, Continental, Thunderbird, Cougar, Mustang and Capri models, disconnect fuel pump power supply wire at fuel pump relay or grommet in trunk.
3. On Mark VII, Continental, Thunderbird, Cougar, and Mustang models, connect VOM between chassis ground and power supply wire with ignition off. If reading is 5 ohms or less, go to step 5). If reading is too high, attach ground lead of VOM to ground lead of pump circuit. If reading is now correct, check body ground or wiring between fuel pump and body ground.
4. If reading is still too high, remove fuel tank and check for continuity across fuel pump terminals. If continuity is shown, check wiring. If there is no continuity, change fuel pump.
5. On all models, connect VOM to body wiring harness connector. Turn ignition on while watching voltmeter. Reading should rise to 10 volts or more on Mark VII, Continental, Thunderbird/Cougar, and Mustang. On Town Car, Crown Victoria, and Grand Marquis, reading should rise to battery voltage. Voltage should then return to zero volts after approximately one second. If voltage does not return to zero, check inertia switch and electrical system.
6. To check low pressure pump, connect VOM across body wiring harness connector. If continuity (5 ohms or less) is present, low pressure pump circuit is electrically okay. If there is no continuity is present, remove fuel tank. Check for continuity at fuel pump/pump sender flange terminals. If there is no continuity is present, replace assembly. If there is continuity present at pump but not at harness connector, service or replace wiring harness to low pressure pump.
7. On all models, check fuel pump pressure and delivery volume. Disconnect fuel return line at fuel rail, using care to avoid spillage. Connect hose from fuel rail fitting to calibrated container holding at least one quart. Connect fuel pressure gauge to fuel pressure relief valve.
8. Remove fuel pump relay and install modified fuel pump relay. Take extended ground lead to convenient location on vehicle. Ground extended lead to activate fuel pump for 10 seconds. Observe pressure while activated.
9. Check delivery volume after all fuel has drained from hose into container. Fuel pump is operating properly if fuel pressure reaches 35-45 psi (2.5-3.2 kg/cm 2 ), delivery volume is minimum of 8.1 ozs. (.24L) for 2.3L turbo and 5.0L HO EFI for 10 seconds. For all other EFI engines delivery volume is a minimum of 5.6 ozs. (.17L) for 10 seconds. Residual pressure holds at minimum of 30.0 psi (2.1 kg/cm 2 ) immediately after pump is shut off.
10. If all 3 conditions are met, fuel pump is operating normally. Check for engine and electrical problems. If pressure is good but volume is not, check for restricted filters or supply lines. After correcting any blockage, recheck. If volume requirements are still not met, replace fuel pump.
11. If both delivery pressure and volume requirements are met, but residual pressure does not hold, check for leaking regulator or injectors. If both test good, replace fuel pump/sending unit. If no flow or pressure is seen, fuel system should be checked as in step 10). If no trouble is found, replace fuel pump/sending unit.
12. On Crown Victoria and Grand Marquis models, check low pressure in-tank pump if hot fuel problems exist or system is noisy. Remove inlet push connect fitting and line from high pressure pump assembly. Raise end of fitting above level of fluid in tank to prevent siphon action.
13. Connect hose from fuel tank to calibrated container holding at least one quart. Turn ignition on until fuel pump times out (approximately one second). Check container for presence of fuel (if necessary, lift container to prevent siphon action). Amount of fuel should be minimum of 1.5 oz. (.04L) for one second of operation.
14. If no fuel is delivered, repeat timing out of fuel pump, twice or 3 times if necessary. If fuel still is not delivered, check for pinched line between fuel tank and fitting. If lines are not pinched, remove fuel tank. Connect VOM to chassis electrical connector from fuel pump and turn ignition on. Reading should rise to battery voltage for one second and then return to zero volts.
15. If reading is correct and electrical connector was okay at pump, replace fuel pump assembly. Repeat low pressure fuel pump test. If no voltage is present, repair electrical circuit in vehicle. If pump tests correctly but sounds noisy, high pressure pump may be at fault.
16. Check inlet and outlet pipes at high pressure pump for vibration during operation. If either line has much greater level of vibration than the other, change high pressure pump. Recheck for vibration and noise while operating.

INJECTOR TESTING

Note. On 5.0L SEFI engine, EEC-IV balance test must be performed to obtain injector balance condition.

1.9L, 2.3L TURBO

1. Connect tachometer to engine and disconnect ISC motor. Run engine at 2000 RPM and lock speed with throttle body stop screw. As engine continues to run, disconnect and reconnect each injector individually. If each injector causes drop in engine speed of at least 150 RPM, injectors are giving proper fuel delivery.
2. Replace any injectors that do not cause sufficient drop in engine speed. When test is completed and all injectors cause equal drop in speed, shut off engine. Reconnect ISC motor and reset curb idle. Refer to emission control specifications on decal in engine compartment.

2.3L, 3.0L

1. Connect tachometer to engine. Run engine at idle. Disconnect and reconnect injectors individually. If each injector causes a momentary drop in engine speed of at least 100 RPM, injectors are giving proper fuel delivery. RPM drop should only be momentary as ISC will attempt to reestablish proper RPM.
2. Replace any injectors that do not cause sufficient drop in engine speed. When test is completed and all injectors cause equal drop in speed, shut off engine. In order to check curb idle refer to emission control specifications on decal in engine compartment.

INJECTOR CIRCUIT TEST

Disconnect all injector harness connectors. Using digital ohmmeter, check resistance across terminals of each injector. Ohmmeter should read 2.0-2.7 ohms on 1.9L and 2.3L Turbo engines, 16.0-18.0 ohms on 3.0L engines or 15.0-19.0 ohms on 5.0L engines. If not, replace injector.

Note. For further component testing and information, see FORD MOTOR CO. ELECTRONIC ENGINE CONTROL IV in COMPUTERIZED ENGINE CONTROL section.

REMOVAL & INSTALLATION

Before completely removing fuel charging assembly or working on component parts while installed on engine, following steps MUST be performed

1. Open hood and install protective covers.
2. Turn ignition off.
3. Disconnect negative battery lead.
4. On 1.9L 2.3L,and 2.3L Turbo models, drain coolant.
5. Remove fuel cap to relieve tank pressure.
6. Release system pressure using pressure gauge at fuel pressure relief valve.
7. On 1.9L and 3.0L models, disconnect fuel supply and return lines.
8. On 1.9L models, disconnect injector wiring harness by disconnecting ECT sensor in heater supply tube under lower intake manifold. Disconnect air by-pass connector from EEC harness.
9. On 3.0L models, disconnect wiring harness at injectors, TPS, air by-pass valve and ACT sensor.

SPRING LOCK COUPLING

Spring lock couplings are available in 3/8" and 1/2" sizes. Use correct end of Spring Lock Coupling Remover (T81P-19623-G) for size of coupling. Place remover against coupling. Push remover into cage opening to release female fitting from garter spring. Pull male and female halves of coupling apart. Remove tool from disconnected spring lock coupling.

PUSH CONNECT FITTING

Push connect fuel line fittings are disconnected by removing hairpin clip from fitting. Spread each clip leg about 1/8" to disengage body. Push legs into fitting. While pulling lightly on triangular end of clip, work it clear of tube and fitting. Pull fitting and steel line in axial direction. Use twisting motion while pulling to break fitting loose.

Removal

1. Remove air cleaner outlet tube between vane air meter and air throttle body by loosening 2 clamps. Disconnect and remove accelerator and speed control cables from accelerator mounting bracket and throttle lever.
2. Disconnect top manifold vacuum fitting connections by disconnecting both rear vacuum line for dash panel vacuum tree and vacuum line at intake tee. Disconnect hoses from PCV valve at intake manifold.
3. Disconnect vacuum line at EGR valve. Disconnect EGR tube from upper intake manifold by loosening compression nut while supporting connector. Remove only upper bolt to disconnect upper manifold support bracket. Disconnect wiring at main engine harness and ECT sensor.
4. Disconnect fuel lines. Remove 6 manifold mounting nuts. Disconnect lower manifold support bracket by removing top bolt. Remove manifold with wiring harness and gasket.

Installation

1. Clean and inspect mounting faces of fuel charging manifold assembly and cylinder head. Surface must be clean and flat. Clean and lubricate manifold stud threads. Install new gasket. Install manifold assembly to head and tighten top middle nut finger tight.
2. Install fuel return line in fuel supply manifold. Install 2 manifold mounting nuts finger tight. Install remaining 3 manifold mounting nuts and tighten all nuts. Connect upper and lower manifold support brackets and tighten bolts. Install EGR tube with oil coated compression nut.
3. Connect vacuum lines to throttle body port. Connect large PCV vacuum line to upper manifold. Reconnect all manifold vacuum lines. Connect accelerator and speed control cables. Install air supply tube and tighten clamps.
4. Reconnect wiring harness at ECT sensor and EEC harness. Connect fuel supply hose from fuel filter to fuel rail. Connect fuel return line. Connect battery ground and refill cooling system.

1. Disconnect electrical connectors at air by-pass valve, TPS, CTS, injector wiring harness, detonation (knock) sensor and fan temperature sensor. Disconnect all upper intake manifold vacuum fittings at cast tube, rear vacuum line from dash panel tee, vacuum line to EGR valve and vacuum line to fuel pressure regulator.
2. Disconnect throttle linkage. Unbolt accelerator cable from bracket and position cable out of way. Remove air charge intercooler. Remove 2 nuts and bolts that secure air throttle body to upper intake manifold.
3. Separate cast tube from turbocharger assembly. Remove and discard gasket. Remove throttle body and cast tube. Disconnect PCV hose from bottom of upper intake manifold. Disconnect hose at water by-pass valve at lower intake manifold.
4. Disconnect EGR tube and valve by removing flange nut. Remove fuel injector pulse dampener mounting bracket. Remove upper intake manifold assembly by removing 2 or 3 studded bolts and 2 plain bolts. Disconnect push connect fuel supply line. Disconnect push connect fittings at return and supply lines at fuel supply manifold.
5. Disconnect wiring from all 4 fuel injectors and move harness aside. Remove 2 fuel supply manifold retaining bolts. Carefully remove fuel supply manifold. Remove 4 bottom retaining bolts from lower manifold. Remove 4 upper retaining bolts from lower manifold. Remove lower intake manifold.

Scheme 19

1. Clean both mounting faces. Surfaces must be clean and flat. Clean and lubricate manifold stud threads. Install new gasket. Position lower manifold assembly on head. Install engine lifting bracket. Install 4 upper manifold retaining nuts finger tight. Install 4 remaining manifold nuts. Tighten all nuts in correct sequence. (Scheme 17)
2. Install fuel supply manifold with 2 retaining bolts. Tighten bolts. Connect wiring to injectors. Make sure gasket surfaces are clean on both manifolds. Place new gasket on lower intake manifold assembly and place upper intake manifold in position. Install retaining bolts and tighten in sequence. (Scheme 17)
3. Install injector pulse mounting bracket and engine oil dipstick. Tighten retaining bolts or nuts. Connect fuel supply and return lines. Connect EGR tube to upper intake manifold and tighten. Connect water by-pass line. Connect PCV system hose to fitting on underside of upper intake manifold. Connect all upper intake manifold vacuum connections, including rear vacuum line from dash panel to vacuum tee, EGR valve and fuel pressure regulator.
4. Hold accelerator cable bracket in position on upper manifold and tighten retaining bolt. Install accelerator cable in bracket. Position cast tube gasket on turbocharger. Be sure surfaces of cast tube and turbocharger are clean. Position new gasket on throttle body mounting flange of fuel charging assembly.
5. Install cast tube/air throttle body assembly on turbocharger, making sure gasket is in correct position. Install 2 cast tube retaining bolts and tighten. Attach air throttle body/cast tube assembly to fuel charging assembly. Install 2 retaining nuts and 2 bolts. Tighten in sequence. (Scheme 17) Connect accelerator cable.
6. Connect wiring at air by-pass valve, TPS, CTS, injector wiring harness, detonation (knock) sensor and fan temperature sensor. Connect battery ground. Refill cooling system. Start engine and check for leaks.

1. Remove air cleaner outlet tube from throttle body. Remove nut and 2 bolts holding snow shield. Remove snow shield. Disconnect vacuum hoses from all fittings on manifold. Disconnect and remove accelerator and speed control cables from mounting bracket and throttle lever.
2. On models with A/T, remove TV linkage from throttle lever. Remove 6 bolts holding air intake/throttle body assembly to lower intake manifold. Remove air intake/throttle body assembly. Remove and discard gasket from lower intake manifold.

Clean both mounting surfaces. Make sure surfaces are flat. Clean and oil stud threads. Install new gasket. Install air intake/throttle body assembly, making sure that guide pins are properly aligned. Install one stud bolt and 5 regular bolts and hand tighten evenly. Tighten all 6 bolts evenly, starting from either short center bolt and working out to bolts on either end.

1. Disconnect wiring from air by-pass valve, TPS and EGR position sensor. Disconnect throttle and transmission linkages from throttle body. Remove cable bracket with cables attached and position out of way. Identify and disconnect all vacuum lines to upper intake manifold.
2. Disconnect PCV system from fitting at rear of upper manifold. Remove 2 canister purge lines from throttle body fittings. Loosen flange nut and remove EGR tube from EGR valve. Remove bolt from upper support bracket at upper manifold. Remove 6 bolts holding upper intake manifold to lower manifold.

Make sure mounting faces are clean and flat. Position new gasket and install upper manifold with throttle body onto lower manifold. To complete installation, assemble all parts in reverse order of removal. If lower intake manifold was loosened or removed, fill and bleed cooling system.

Disconnect engine air cleaner outlet tube from air intake throttle body. Unplug TPS from wiring harness. Unplug air by-pass valve connector. Disconnect vacuum lines and EGR connection. Remove top bolt from upper manifold support bracket. Remove 5 upper manifold retaining bolts. Remove upper manifold assembly. Remove gasket from lower manifold.

Make sure gasket surfaces of upper and lower intake manifold are clean. Place new gasket on lower manifold and mount upper manifold to lower with 5 bolts. Attach electrical connectors to air by-pass valve and throttle position sensor.

Disconnect electrical connectors at TPS, air by-pass valve, knock sensor, and EGR valve. Disconnect upper intake manifold vacuum fittings. Disconnect throttle linkage, cruise control, and kickdown cable. Remove accelerator cable. Disconnect air intake hose, crankcase vent hose, PCV, and 4 upper intake manifold bolts. Remove upper intake manifold assembly.

Reverse removal procedure. Ensure that all gasket surfaces are clean. Place new gasket on lower manifold assembly and tighten 4 bolts. Add coolant as necessary

1. Disconnect electrical connector at air by-pass valve and throttle position sensor. Disconnect upper intake manifold vacuum fitting connections by disconnecting vacuum line fitting at cast tube. Disconnect rear vacuum line to dash panel tee.
2. Disconnect vacuum line to EGR valve. Disconnect throttle linkage. Unbolt accelerator from bracket and position cable out of way. Remove bolts that attach cast tube assembly to turbocharger assembly. Remove nuts that secure air throttle body to fuel charging assembly.
3. Separate cast tube from turbocharger assembly. Remove and discard gasket between cast tube and turbocharger. Remove throttle body and cast tube. Disconnect PCV system by disconnecting hose from fitting on underside of upper intake manifold.
4. Disconnect EGR tube from EGR valve. Remove fuel injector wiring harness bracket retaining nuts and remove bracket. Remove upper intake manifold mounting bolts and studs. Remove upper intake manifold assembly. Remove and discard gasket from lower manifold assembly.

1. Make sure gasket surfaces of upper and lower manifolds, turbocharger and cast tube are clean. Place new gasket on lower manifold assembly and mount upper intake manifold to lower assembly. Tighten bolts and nuts.
2. Install injector wiring harness and engine oil dipstick bracket. Connect EGR tube to EGR valve. Connect PCV system. Connect vacuum connections. Position cast tube gasket on turbocharger. Install retaining bolts and tighten. Install air throttle body/cast tube assembly to fuel charging assembly.
3. Install retaining nuts and tighten. Connect accelerator cable. Connect electrical connectors to air by-pass valve and throttle position sensor. Connect negative battery cable and fill cooling system.

Remove 2 nuts and 2 bolts from throttle body. Disconnect TPS connector and air by-pass valve connector. Disconnect air cleaner outlet tube. Identify and disconnect vacuum hoses. Disconnect throttle and speed control cables. Remove throttle bracket. Carefully separate throttle body from upper intake manifold. Remove and discard gasket.

Ensure that gasket surfaces are clean. Install throttle body gasket on 2 studs. Secure throttle body to upper intake manifold with 2 nuts and 2 bolts. Install throttle bracket. Reconnect air by-pass valve and TPS electrical connectors. Connect all vacuum lines. Connect air cleaner outlet tube to throttle body intake.

1. Remove throttle cable, cruise control, and TPS. Unplug connectors at EGR and air by-pass valve. Remove air intake hose, crankcase vent hose, 2 throttle body nuts (lower), and 2 bolts (upper).
2. Separate air throttle body from upper intake manifold. Discard gasket between throttle body and upper intake manifold.

Ensure that gasket surfaces are clean. Reverse removal procedure and tighten all nuts and bolts to specifications.

AIR INTAKE THROTTLE BODY R & I - 2.3L TURBO & 5.0L

Remove throttle body bolts and nuts. Make sure TPS connector and air by-pass valve connector have been disconnected. Carefully separate throttle body from upper intake manifold. To install, reverse removal procedure, using new gasket.

Disconnect TPS from wiring harness. Make scribe marks on throttle body and TPS for reassembly reference. Remove TPS.

Slide rotary tangs of TPS into position over throttle shaft blade with wires pointing down. On 3.0L models, Red seal must be inside connector housing. On all models, rotate TPS clockwise to installed position. Align scribe marks on throttle body and TPS. Secure sensor to throttle body assembly with retaining bolts. Connect wiring.

1. Remove fuel tank cap and release pressure from system by opening pressure relief valve on fuel line in upper right corner of engine compartment. On 3.0L and 5.0L engines relief valve is located on intake manifold. Disconnect fuel supply and return lines.
2. Disconnect wiring harness from injectors. Disconnect vacuum line from fuel pressure regulator valve. Remove fuel injector manifold retaining bolts. Disengage manifold from fuel injectors and remove manifold. Grasp injector body and pull up while gently rocking injector.

1. Inspect "O" rings, "plastic hat" and washer over injector pintle. Make sure injector caps are clean. Use light twisting motion to install injectors in manifold assembly. Make sure injectors are well seated in fuel manifold assembly.
2. Assemble manifold to charging assembly with retaining bolts. Connect fuel supply and return lines. Connect fuel injector wiring harness. Connect vacuum line to fuel pressure regulator.

Remove vacuum line at pressure regulator. Remove 3 Allen retaining screws from regulator housing. Remove pressure regulator assembly with gasket and "O" ring. Discard gasket and inspect "O" ring for cracks or deterioration.

Lubricate "O" ring with light oil. Make sure gasket surfaces are clean. Install "O" ring and new gasket on regulator. Install fuel pressure regulator on injector manifold and tighten 3 screws.

1. Disconnect air cleaner outlet hose from air meter assembly and position hose out of way. Remove air intake tube from air cleaner. Disengage 2 spring clamps. Remove air cleaner front cover and air cleaner filter panel.
2. Remove 4 screws and washers from flange of air cleaner where it attaches to vane air meter assembly. Pull air cleaner base away from vane air meter and remove air cleaner gasket. Remove electrical connector from vane air meter assembly. Remove 3 screws and washers attaching vane air meter to bracket and remove air meter.

1. Clean mounting surfaces. Mount vane air meter on air cleaner tray, making sure gasket is seated and aligned. Secure air meter assembly to air meter bracket with 3 special screw/washer assemblies (2 of No. N605786-S2 and 1 No. N605789-S2 screw). These screws are different sizes and must go in correct opening.
2. Connect vane air meter inlet hose and tighten clamp. Install air cleaner housing/vane meter bracket to fender wall with 4 retaining screws. Connect all hoses to air cleaner housing. Connect air meter electrical connector. Install air cleaner element and housing cover.

Remove air cleaner cover and element. Disconnect carbon canister hose. Disconnect vane air meter electrical connector. Disconnect turbocharger air inlet hose from vane air meter. Remove 4 bolts holding air cleaner housing to vane air meter bracket. Remove vane air meter and air cleaner housing bracket. Remove hose from vane air meter. Remove vane air meter.

Make sure mounting surfaces are clean. Mount air vane meter on air cleaner housing bracket. Secure air meter assembly to air meter bracket with 3 special screw/washer assemblies (2 of No. N802748-S2 and 1 No. N602736-S2 screw). These screws are different sizes and must go in correct opening. Reverse removal procedure to complete installation.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

1.9L MPFI System Wiring Diagram. Scheme 20

2.3L MPFI System Wiring Diagram. Scheme 21

2.3L Turbo MPFI System Wiring Diagram. Scheme 22

3.0L MPFI System Wiring Diagram. Scheme 23

5.0L SPFI System Wiring Diagram. Scheme 24