Fuel Injection System - Multi-Point Ford Thunderbird IX

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 System is a multipoint, pulse time system using a mass air flow sensor. Fuel is metered into the intake air stream in accordance with engine demand through injectors mounted on a tuned intake manifold.

An on board Electronic Engine Control (EEC IV) computer uses inputs from various engine sensors to compute the required fuel flow rate necessary to maintain a prescribed air/fuel ratio throughout the entire engine operational range. The computer then outputs a command to the fuel injectors to meter the approximate quantity of fuel.

Note. Additional information may be found in the appropriate article in this section. See the following article

1. «EEC IV THEORY/OPERATION»(/ford/thunderbird/ix-1983-1988/remont/theory-operation/#eec-iv-theoryoperation)

Typical 1.6L Engine With Multi-Point Injection. Scheme 17

FUEL DELIVERY

The fuel delivery sub-system uses a high pressure electric fuel pump mounted on the chassis. Pump delivers fuel from the fuel tank through a 2 micron fuel filter to a fuel charging manifold assembly. The fuel charging manifold assembly incorporates electrically actuated fuel injectors directly above each of the engine's intake ports. The injectors spray a metered quantity of fuel into the intake air stream.

A constant fuel pressure drop is maintained across the injector nozzles by a pressure regulator. The regulator is connected in series with the fuel injectors and is positioned downstream from them. Excess fuel supplied by the pump, but not required by the engine, passes through the regulator and returns to the fuel tank through a fuel return line.

All injectors are energized simultaneously, once every crankshaft revolution. The period of time that the injectors are energized (injector "on time" or "pulse width") is controlled by the vehicles' ECA. Air entering the engine is measured by a vane air flow meter located between the air cleaner and the turbocharger or fuel charging manifold assembly.

Typical 2.3L Turbo Engine with Multi-Point Injection System. Scheme 18

This air flow information and input from various other engine sensors is used to compute the required fuel flow rate necessary to maintain a prescribed air/fuel ratio for the given engine operation. The computer determines the needed injector pulse width and outputs a command to the injector to meter the exact quantity of fuel.

FUEL INJECTORS

The fuel injector nozzles are electro-mechanical devices which both meter and atomize fuel delivered to the engine. The injectors are mounted in the lower intake manifold and are positioned so their tips direct fuel just ahead of the engine intake valves.

The injector bodies consist of a solenoid actuated pintle and needle valve assembly. An electrical control signal from the Electronic Engine Control unit activates the injector solenoid, causing the pintle to move inward off the seat, allowing fuel to flow.

Since the injector flow orifice is fixed and the fuel pressure drip across the injector tip is constant, fuel flow to the engine is regulated by how long the solenoid is energized. Atomization is obtained by contouring the pintle at the point where the fuel separates.

FUEL PRESSURE REGULATOR

The fuel pressure regulator is attached to the fuel supply manifold assembly downstream of the fuel injectors. It regulates the fuel pressure supplied to the injectors. The regulator is a diaphragm operated relief valve. One side of the diaphragm senses fuel pressure. The other side is subjected to intake manifold pressure.

The nominal fuel pressure is established by a spring preload applied to the diaphragm. Balancing one side of the diaphragm with manifold pressure maintains a constant fuel pressure drop across the injectors. Excess fuel not used by the engine is by-passed through the regulator and returns to the fuel tank.

1.6L Engine Fuel Charging Manifold Assembly. Scheme 19

2.3L Engine Fuel Charging Manifold Assembly (Mustang SVO shown, other similar). Scheme 20

AIR VANE METER ASSEMBLY

The vane air meter contains 2 sensors which furnish input to the ECA, an airflow sensor and a vane air temperature sensor. The air vane meter measures the volume of air flow to the engine. Air flow through the body moves a vane mounted on a pivot pin. The vane is connected to a variable resistor (potentiometer) which in turn is connected to a 5-volt reference voltage.

The output of this potentiometer varies depending on the volume of air flowing through the sensor. The temperature sensor in the air vane meter measures the incoming air temperature. The air volume and temperature inputs are used by the ECA to compute the fuel flow (injector pulse duration) necessary for the optimum air/fuel ratio.

FUEL SUPPLY MANIFOLD ASSEMBLY

The fuel supply manifold assembly is the component that delivers high pressure fuel from the vehicle fuel supply line to the fuel injectors. The assembly consists of a single preformed tube or stamping with injector connectors, a mounting flange to the fuel pressure regulator, and mounting attachments which locate the fuel manifold assembly and provide fuel injector retention.

AIR THROTTLE BODY ASSEMBLY

The throttle body assembly controls air flow to the engine through a single butterfly valve. The throttle position is controlled by multiple-link throttle linkage that opens progressively on all vehicles with 2.3L engines. On vehicles with 1.6L engines, it is controlled by a conventional cable/cam throttle linkage. On all models, the body is a single piece die casting made of aluminum. It has a single bore with an air by-pass channel around the throttle plate.

This by-pass channel controls both cold and warm engine idle airflow control as regulated by an air by-pass valve assembly mounted directly to the throttle body. The valve assembly is an electro-mechanical device controlled by the ECA. It incorporates a linear actuator which positions a variable area metering valve.

AIR INTAKE MANIFOLD

The air intake manifold is a 2-piece (upper and lower intake manifold) aluminum casting. Runner lengths are tuned to optimize engine torque and power output. The manifold provides mounting flanges for the air throttle body assembly, fuel supply manifold, accelerator control bracket, EGR valve and supply tube.

Vacuum taps are provided to support various engine accessories. Pockets for the fuel injectors are machined to prevent both air and fuel leakage. The pockets in which the injectors are mounted are placed to direct the injector fuel pump immediately in front of each engine intake valve.

ADJUSTMENTS

For all on-vehicle adjustments, see appropriate TUNE-UP article. Refer to the following menu

1. All except Canadian models, see: «TUNE-UP - 4-CYL»(/ford/thunderbird/ix-1983-1988/remont/adjustments/#tune-up-4-cyl)
2. Canadian models, see: «TUNE-UP - 4-CYL (CANADA)»(/ford/thunderbird/ix-1983-1988/remont/adjustments/#tune-up-4-cyl-canada)

PRELIMINARY CHECKS

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

1. All support systems and wiring
2. Battery connections and specific gravity.
3. Ignition System.
4. Compression pressure
5. Fuel supply system pressure and flow.
6. All electrical connections and terminals.
7. Vacuum line, fuel hose and pipe connections.
8. Air cleaner and air ducts.
9. Engine coolant level.

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

ENGINE DOES NOT CRANK

Check for hydrostatic lock (liquid in cylinder) and repair as needed. Check for starting and charging system problems.

ENGINE CRANKS BUT DOES NOT START

1. See fuel tank contains an adequate amount of fuel. DO NOT assume that fuel gauge is correct.
2. Check ignition system for strong secondary current at spark plugs. If none exists or 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. Reset inertia switch if necessary.

HARD COLD START

1. Choke system may not be functioning correctly. Check linkage for proper operation and adjustment. Clean, service or replace as required.
2. Choke thermostat housing may be incorrectly adjusted. Adjust choke thermostat setting if needed. If it is a tamperproof type, check for incorrect assembly.
3. Intake manifold or fuel charging assembly baskets may be leaking. Replace leaking gaskets as needed.

ROUGH COLD IDLE

1. Choke system may not be functioning correctly. Check linkage for proper operation and adjustment. Clean, service, or replace as required. Check pulldown adjustment.
2. Fast idle adjustments may be improper. Perform fast idle adjustments. Air cleaner duct vacuum motor may be damaged or stuck open. Replace or service as required. Check for possible vacuum leak.

STALL, STUMBLE, OR HESITATION WHEN HOT OR COLD

1. Choke system may not be functioning correctly. Check linkage for proper operation and adjustment. Clean, service, or replace as required. Check choke pulldown.
2. Fuel pump output may be low. Service or replace as required. Fuel filter may be clogged. Clean or replace as required. Determine cause. Air cleaner vacuum motor may be damaged. Service or replace as required.

HARD HOT START

1. Choke system may not be functioning correctly. Check linkage for proper operation and adjustment. Clean, service, or replace as required.
2. Choke thermostat housing may be incorrectly adjusted. Adjust choke thermostat setting if needed. If it is a tamperproof type, check for incorrect assembly.
3. Intake manifold or fuel charging assembly gaskets may be leaking. Replace leaking gaskets as needed.

ROUGH HOT IDLE

Choke system may not be functioning correctly. Check linkage for proper operation and adjustment. Clean, service, or replace as required. Check for possible vacuum leak.

STALLS ON DECELERATION OR QUICK STOP

Throttle positioner may be functioning improperly. Service as required. Intake manifold or fuel charging assembly gaskets may be leaking. Replace leakage gaskets as needed.

LACK OF POWER

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

REDUCED TOP SPEED/POWER

1. Throttle linkage may be binding. Clean and service as required.
2. Fuel pump volume may be low. Test fuel delivery system.
3. Fuel filter may be clogged. Determine cause and replace as required.
4. Injectors may be plugged. Repair or replace as needed.
5. Pressure regulator may be damaged. Repair or replace as needed.

SURGE AT CRUISE

1. Fuel filter may be clogged. Determine cause and replace filter.
2. Fuel pump pressure or volume may be low. Test fuel delivery system.
3. Fuel may be contaminated. Drain fuel and clean system as needed.

2.3L Engines

1. Check fuel tank for adequate fuel supply. Check for fuel leakage at all fittings and lines.
2. Check for electrical continuity to the fuel pump(s). On a single pump system, disconnect electrical connect just forward of the fuel pump inlet. On dual pumps, disconnect electrical connector to fuel pumps at high pressure pump module. Connect voltmeter to body wiring harness connector. Turn ignition key to "ON" position while watching the voltmeter.
3. Voltage should rise to battery voltage and then return to zero voltage after approximately one second. If voltage is not as specified, check inertia switch and electrical system. Connect ohmmeter to pump wiring harness connector. If no continuity is present, check continuity directly at pump terminals. If no continuity is at pump terminals, replace pump(s). If continuity is present at terminals, service and replace wiring harness.
4. For dual pump systems only, connect the ohmmeter across the body wiring harness connector. If continuity is present (about 5 ohms), low pressure pump circuit is electrically okay.
5. For dual pump systems only, if no continuity is present in step 4), it is necessary to remove fuel tank and check for continuity at fuel pump/pump sender flange terminals. If no continuity at pump flange terminals is present, replace the assembly. If continuity is present at pump but not in step 4), service or replace the wiring harness in the low pressure pump.
6. Check operation of fuel pump(s). Disconnect return line at fuel rail. Use care to avoid spillage. Connect hose from fuel rail fitting to a calibrated container of at least one quart. Connect pressure gauge to fuel diagnostic valve on fuel rail. Disconnect the electrical connector to the electric fuel pump(s) located just forward of the pump outlet.
7. Connect auxiliary wiring harness to the electrical connector to the fuel pump. Energize the fuel pump(s) for 10 seconds by connecting the auxiliary wiring harness to a fully charged 12-volt battery. Observe pressure while energized. If no pressure, check polarity of wiring harness and also check terminal connections at fuel pump(s).
8. Allow fuel to drain from hose into container and observe the volume. The fuel pump(s) are operating properly if; fuel pressure reaches 35-45 psi (2.5-3.2 kg/cm 2 ), fuel flow is a minimum of 7.5 oz (220 cc) for a single pump system; 9.5 oz. (280 cc) for a dual pump system, in 10 seconds, and fuel pressure remains at a minimum of 30 psi (2.1 kg/cm 2 ) immediately after di-energizing.
9. If all 3 conditions are met, the fuel pump is operating normally. If pressure condition is met but flow is not, check for blocked filter(s) and fuel supply lines. After correcting any blockage, recheck using step 8). If flow conditions are still not met, replace fuel pump.
10. If both pressure and flow conditions are met, but pressure will not maintain after de-energizing, check but leakage at the regulator or injectors. If both check okay, replace fuel pump.
11. If no flow or pressure is seen, the fuel system should be checked as in step 9). If no trouble is found, replace the fuel pump, drop the fuel tank and replace the fuel filter on the filler neck tube or on the low pressure pump, depending on application.
12. On a system with 2 fuel pumps, if hot fuel problems exist or system is noisy, check the low pressure in-tank pump as follows. Remove inlet push connect fitting and line from high pressure pump assembly. CAUTION: Raise end of fitting above level of fluid in tank to prevent a siphon action.
13. Connect hose from fuel tank to a calibrated container of at least one quart. Place ignition key in the "RUN" position until fuel pump times out (approximately one second). Check container for presence of fuel (if necessary, lift container to prevent siphon action). The amount of fuel should be a minimum of 1.5 oz. (50 cc) for one second of operation.
14. If no fuel is present, recycle ignition key. If no fuel is present, check for a pinched line between the fuel tank and fitting, and then proceed to drop the fuel tank.
15. Connect a voltmeter to the chassis electrical connector from the fuel pump and turn ignition key to "ON" position. Voltage should rise to battery voltage for one second and then return to zero volts. If voltage is as specified and electrical connector was okay at pump, replace fuel pump assembly and repeat low pressure fuel pump test. If no voltage is present, service electrical circuit in vehicle.

1.6L Engines

1. Check fuel tank for adequate fuel supply. Check for fuel leakage at all fittings and lines. Check for electrical continuity to fuel pump. Disconnect electrical connector just forward of the fuel pump inlet. Connect voltmeter to body wiring harness connector. Turn key to "ON" position while watching voltmeter.
2. Voltage should rise to battery voltage, and then return to zero voltage after approximately one second. If voltage is not as specified, check inertia switch and electrical system. Connect continuity tester to pump wiring harness connector. If no continuity is present, check continuity directly at pump terminals. If no continuity is at present at pump terminals, replace pump. If continuity is present, service or replace harness.
3. Check electric fuel pump operation. Disconnect return line at fuel rail. Use care to avoid fuel spillage. Connect hose from fuel rail fitting to a calibrated container of at least one quart. Connect pressure gauge to fuel diagnostic valve on fuel rail. Disconnect the electrical connector to the electric fuel pump located just forward of the pump outlet, if not already disconnected from steps 1) and 2).
4. Connect auxiliary wiring harness to the electrical connector to the fuel pump. Energize the fuel pump for 10 seconds by connecting the auxiliary wiring harness to a fully charged 12-volt battery. Observe pressure while energized. If no pressure, check polarity of wiring harness and also, check terminal connections at fuel pump. Allow fuel to drain from hose into the container and observe volume.
5. The fuel pump is operating properly if the fuel pressure reaches 35-45 psi (2.5-3.2 kg/cm 2 ), fuel flow is a minimum of 7.5 oz. (220 cc) in 10 seconds, and fuel pressure remains at a minimum of 30 psi (2.1 kg/cm 2 ) immediately after de-energization.
6. If all 3 conditions are met, the fuel pump is operating normally. Check for engine and electrical problems. If pressure condition is met, but flow is not, check for blocked filters and fuel supply lines. After correcting any blockages, recheck. If flow conditions are still not met, replace fuel pump.
7. If both pressure and flow conditions are met, but pressure will not remain after de-energization, check for leaking regulator or injectors. If both check okay, replace fuel pump. If no flow or pressure is seen, the fuel system should be checked as in step 5). If no trouble is found, replace the fuel pump, drop the fuel tank and replace the fuel filter on the pick-on tube.

INJECTORS

Pressurize the fuel system and disconnect the wiring connectors from all 4 injectors. Connect a fuel pressure gauge to the pressure relief valve on the fuel rail. Connect one injector at a time and crank engine for 5 seconds. Record pressure immediately after cranking. Repeat procedure for all 4 injectors. Pressure readings of all injectors should be within 4 psi (.3 kg/cm 2 ) of each other. If any injector is outside this range it must be replaced.

Note. For sensor and component testing, see the appropriate TESTING article in this section. See the following article

1. For 1.6L & 2.3L engines, see: «1.6L & 2.3L EFI/TURBO TESTS»(/ford/thunderbird/ix-1983-1988/remont/testing-diagnostics/#16l-23l-efiturbo-tests)

Scheme 21

1. Disconnect electrical connectors at air by-pass valve, TPS, injector wiring harness, knock sensor, fan temperature sensor and coolant temperature sensor. Disconnect upper intake manifold vacuum fitting connections by disconnecting vacuum line fitting at cast tube.
2. Disconnect rear vacuum line to dash panel tee, and vacuum line to EGR valve. Disconnect vacuum line to fuel pressure regulator. Disconnect throttle linkage. Unbolt accelerator cable from bracket and position cable out of the way. Remove 2 bolts that attach cast tube to turbocharger assembly. Remove 4 nuts that secure air throttle body to fuel charging assembly.
3. Separate cast tube from turbocharger assembly. Remove and discard gasket. Remove throttle body and cast tube. Disconnect PCV system by disconnecting hose from fitting on under side of upper intake manifold. Disconnect hose at water by-pass valve at lower intake manifold.
4. Disconnect EGR tube from EGR valve by removing flange nut. Remove the fuel injector wiring harness bracket retaining nut. Remove bracket. Remove upper intake manifold retaining studs and bolts. Remove upper intake manifold assembly.
5. Disconnect the push connect fuel supply line by removing the hairpin clip from the fitting. This is done by spreading the clip legs about 1/8" to disengage it from the body, and pushing legs into fitting. (Scheme 21) Lightly pull the triangular end of the clip and work it clear of tube and fitting. Grasp fitting and hose and pull in axial direction, twisting to break loose. (Scheme 21): Push Connect Clip With Hairpin Clip
6. Using Quick Connect Removal Tool (T82L-9500-AH), disconnect the fuel return line from the fuel supply manifold. Disconnect the electrical connectors from all 4 fuel injectors. 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.

Scheme 22

Scheme 23

1. Clean and inspect mounting faces of the fuel charging manifold assembly and cylinder head. Surfaces must be clean and flat. Clean and lubricate manifold stud threads. Install new gasket. Position the lower manifold assembly to head and install engine lifting bracket.
2. Install 4 upper manifold retaining nuts fingertight. Install 4 remaining manifold nuts and tighten all nuts in sequence. (Scheme 22)and (Scheme 23). Install the fuel supply manifold with 2 retaining nuts. Tighten bolts. Connect 4 electrical connectors to injectors. Make sure gasket surfaces are clean. (Scheme 22): Upper and Lower Intake Manifold Tightening Sequence for Mustang SVO (Scheme 23): Upper and Lower Intake Manifold Tightening Sequence for Capri, Cougar, Mustang (Except SVO) and Thunderbird
3. Place a new gasket on lower intake manifold assembly and place the upper intake manifold in position. Install retaining bolts and tighten. Install engine oil dipstick and injector wiring harness bracket. Tighten retaining bolts or nuts. Connect fuel supply and return lines. Connect EGR tube to upper intake manifold and tighten.
4. Connect water by-pass line. Connect the PCV system hose to the fitting on the underside of the upper intake manifold. Connect upper intake manifold vacuum connections, including rear vacuum line from dash panel to vacuum tee, EGR valve and fuel pressure regulator. Hold accelerator cable bracket in position on upper manifold and install retaining bolt.
5. Tighten bolt. Install accelerator cable top bracket. Position cast tube gasket on turbocharger. Be sure surfaces of cast tube and turbocharger are clean. Position new gasket on fuel charging assembly and throttle body mounting flange.
6. Install cast tube/air throttle body assembly on the turbocharger. Make sure gasket is in correct position. Install 2 cast tube retaining bolts and tighten. Install air throttle body/cast tube assembly to fuel charging assembly. Install 4 retaining nuts. Connect accelerator cable.
7. Connect electrical connectors to air by-pass valve, throttle position sensor, injector wiring harness, knock sensor, fan temperature sensor and coolant temperature sensor. Connect battery ground. Refill cooling system.

Removal (Escort, EXP & Lynx)

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 rear vacuum line to dash panel vacuum tee, and front vacuum line to air cleaner and fuel pressure regulator. Disconnect PCV system by disconnecting hoses from 2 large forward facing connectors on the throttle body and intake manifold.
3. Disconnect throttle body port hose at straight plastic connector. Disconnect canister purge line at straight plastic connector. Disconnect PCV hose at rocket cover. Unbolt PCV separator support bracket from cylinder head and remove PCV system.
4. Disconnect EGR vacuum line at EGR valve. Disconnect EGR tube from upper intake manifold by removing 2 flange nuts. Pull out the dipstick and remove the tube after removing the tube bracket mounting nut. Remove fuel return line. Remove 6 manifold mounting nuts. Remove manifold with wiring harness and gasket.

Installation

1. Clean and inspect the mounting faces of the 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 fingertight.
2. Install fuel return line in the fuel supply manifold. Install 2 manifold mounting nuts fingertight. Install dipstick in block and secure with bracket fingertight. Install remaining 3 manifold mounting nuts and tighten all nuts. Install EGR tube with 2 oil coated flange nuts.
3. Mount separator bracket to head. Install hose on rocker cover. Connect vacuum lines to throttle body port. Connect large PCV vacuum line to throttle body. Connect large PCV vacuum line to upper manifold. Connect manifold vacuum connections, including rear connection to vacuum tee, front connection to fuel pressure regulator and air cleaner.
4. Connect accelerator and speed control cables. Install air supply tube and tighten clamps. Connect wiring harness at ECT sensor in heater supply tube, and Electronic Engine Control harness. Connect the fuel supply hose from the fuel filter to the fuel rail. Connect the fuel return line. Connect battery ground and refill cooling system.

Disconnect engine air cleaner outlet tube from air intake throttle body. Unplug throttle position sensor from the wiring harness. Unplug the air by-pass valve connector. Remove 3 upper manifold retaining bolts. Remove upper manifold assembly and set aside. Remove gasket from lower manifold.

Make sure the gasket surfaces of the upper and lower intake manifold are clean. Place a new gasket on lower manifold and mount upper manifold to lower with 3 bolts. Install wiring harness. Install electrical connectors to air by-pass valve and throttle position sensor. Connect vacuum hose to fuel pressure regulator.

Removal (All Except Escort, EXP & Lynx)

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 2 bolts that attach cast tube assembly to turbocharger assembly. Remove 4 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 the 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 the gasket surfaces of the upper and lower manifold and turbocharger to cast tube surfaces are clean. Place a new gasket on lower manifold assembly and mount upper intake manifold to lower. 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 4 throttle body nuts. Make sure the throttle position sensor connector and air by-pass valve connector have been disconnected from the harness. Disconnect air cleaner outlet tube. Identify and disconnect vacuum hoses. Remove throttle bracket. Carefully separate the throttle body from upper intake manifold

1. Make sure that gasket surfaces are clean. Install the upper throttle body gasket on the studs of the upper intake manifold. Secure the throttle body to the upper intake manifold with retaining nuts. Install throttle bracket and secure with 2 nuts.
2. Connect air by-pass valve and TPS electrical connectors and vacuum lines. If fuel charging assembly is still mounted to engine, connect air cleaner outlet tube to throttle body intake, securing with hose clamp.

Removal & Installation (All Except Escort, EXP & Lynx)

Remove 4 throttle body nuts. Make sure the throttle position sensor connector and air by-pass valve connector have been disconnected from the harness. Carefully separate the throttle body from upper intake manifold. To install, reverse removal procedure, using new gasket.

Removal

Disconnect the TPS from the wiring harness. Make scribe marks on air throttle body and on TPS reassembly reference. Remove TPS retaining screws. Remove TPS.

Slide rotary tangs on TPS into position over throttle shaft blade. Rotate TPS clockwise to installed position only. Wires should point down. Align scribe mark on air throttle body and TPS. Secure sensor to throttle body assembly with 2 retaining screws. Install electrical connector bolts (if equipped). Connect the electrical connector to the harness.

1. Removal fuel tank cap and release pressure from fuel system at fuel pressure relief valve using EFI Gauge (T801-9974-A). Disconnect fuel supply and fuel return lines. Disconnect wiring harness from injectors. Disconnect vacuum line from fuel pressure regulator valve. Remove 2 fuel injector manifold retaining bolts. Disengage manifold from the fuel injectors and remove manifold.
2. Spread 2 clip legs from 1/8" each to disengage body and push leg into fitting. (Scheme 21) Grasp fitting and hose and pull in axial direction, twisting to break loose. Disconnect fuel return line from the fuel supply manifold. Disconnect electrical connectors from injectors.

Installation (All Models)

Make sure injector caps are clean. Place fuel injector manifold over the 4 injectors making sure they are well seated in the fuel manifold assembly. Assemble the manifold to charging assembly with 2 retaining bolts. Connect fuel supply and return lines. Connect fuel injector wiring harness. Connect vacuum line to fuel pressure regulator.

Remove fuel tank cap and release pressure from fuel system at fuel pressure relief valve using EFI Gauge (T801-9974-A). Remove vacuum line at pressure regulator. Remove 3 Hex retaining screws from regulator housing. Remove pressure regulator assembly, gasket, and "O" ring. Discard gasket and inspect "O" ring.

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

1. Remove fuel tank cap and release pressure from fuel system at fuel pressure relief valve using EFI Gauge (T801-9974-A). Disconnect fuel supply and return lines. Remove vacuum line from fuel pressure regulator. Disconnect fuel injector wiring harness.
2. Remove fuel injector manifold assembly. Carefully remove connectors from injectors. Grasping the injector body, pull up while gently rocking the injector from side-to-side.

1. Inspect "O" rings and injector "plastic hat" and washer. Replace if there are any signs of deterioration. Lubricate new "O" rings and install 2 of each injector.
2. Install injectors, using a light, twisting, pushing motion. Carefully seat the fuel injector manifold assembly on injectors and secure with attaching bolts. Connect vacuum line to fuel pressure regulator. Connect fuel injector wiring harness. Connect fuel supply and return lines.

1. Loosen the hose clamp securing engine air cleaner outlet hose to the vane air meter assembly and position outlet hose out of the way. Remove air intake and air outlet tube from air cleaner. Disengage 3 spring clamps and 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 the 2 screws and washers attaching vane air meter to bracket and remove air meter.

1. Remove air cleaner cover and element. Disconnect carbon canister hose. Disconnect vane air meter electrical connector. Loosen hose clamp on turbocharger air inlet hose and disconnect hose at vane air meter. Remove 4 air cleaner housing/vane air meter bracket retaining screws.
2. Remove fuel injector manifold assembly. Carefully remove connectors from injectors. Grasping the injector body, pull while gently rocking the injector from side-to-side.

1. Inspect "O" rings and injector "plastic hat" and washer. Replace if there are any signs of deterioration. Lubricate new "O" rings and install 2 on each injector.
2. Install injectors, using a light, twisting, pushing motion. Carefully seat the fuel injector manifold assembly on injectors and secure with attaching bolts. Connect vacuum line to fuel pressure regulator. Connect fuel injector wiring harness. Connect fuel supply and return lines.

1. Loosen the hose clamp securing engine air cleaner outlet hose to the vane air meter assembly and position outlet hose out of the way. Remove air intake and air outlet tube from air cleaner. Disengage 4 spring clamps and 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 and remove air cleaner gasket. Remove electrical connector from vane air meter assembly. Remove the 2 screws and washers attaching vane air meter to bracket and remove air meter.

1. Remove air cleaner cover and element. Disconnect carbon canister hose. Disconnect vane air meter electrical connector. Loosen hose clamp on turbocharger air inlet hose and disconnect hose at vane air meter. Remove 4 air cleaner housing/vane air meter bracket retaining screws.
2. Remove vane air meter and air cleaner housing bracket. Loosen vane air meter inlet hose clamp and remove hose from vane air meter. Remove vane air meter retaining screw and vane air meter.

1. Clean mounting surfaces. Mount vane air meter on air cleaner housing bracket. Secure with 3 special screws (2 number N802748-S2 screws and 1 number N602736-S2 screw). Connect vane air meter inlet hose and tighten clamp.
2. Install air cleaner housing/vane meter bracket to fender wall with 4 retaining screws. Connect turbocharger air inlet hose to vane air meter outlet flange. Connect vane air meter electrical connector. Connect carbon canister hose. Install air cleaner element and housing cover.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

1985 1.6L & Turbo Multi-Point Injection System Wiring Diagram. Scheme 24

1985 2.3L Turbo Multi-Point Injection System Wiring Diagram. Scheme 25

See also:
• EEC IV THEORY/OPERATION
• TUNE-UP - 4-CYL
• TUNE-UP - 4-CYL (CANADA)
• 1.6L & 2.3L EFI/TURBO TESTS