Fuel Injection System - Diesel Mercury Topaz I

COMPONENT TESTING

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

DESCRIPTION

The 2.0L engine uses a Nippondenso mechanical high pressure fuel injection pump. The injection pump meters an exact amount of fuel to the fuel injectors, as required by engine operating conditions.

Fuel injection pump is belt-driven, by camshaft, through rear camshaft timing belt. High pressure fuel lines deliver fuel from injection pump to injection nozzles mounted in the cylinder head.

A fuel filter/conditioner is located in the fuel line between the fuel tank and injection pump. A quick start and afterglow system is used to assist in starting when engine is cold.

FUEL INJECTION PUMP

Diesel fuel is drawn from the tank by the injection pump's integral feed pump. Fuel supplied to injection pump is sent into the plunger by the control sleeve in an amount proportional to accelerator pedal position. Control sleeve is linked to the accelerator pedal. The plunger directs high pressure fuel through the delivery valve, into the fuel lines, then to the injectors.

Injection pump fuel pressure is proportional to engine speed. A pressure regulating valve is built into the pump. Any fuel leaking at sliding section of the injector needle valve at time of injection is returned to the housing through the return line. Fuel circulates through the housing to cool and lubricate the pump. Surplus fuel is returned to the tank through the return line.

A fuel cut-off solenoid, located on the pump, is activated with the ignition switch in the "RUN" or "START" position. It interrupts fuel flow on the distributor side of the injection pump when the ignition switch is turned off. This closes the intake port of the plunger and stops the engine.

INJECTORS

The injection nozzles inject fuel directly into the pre-combustion (swirl) chamber. Injectors are connected in series with each other with a fuel return line. When fuel from the injection pump reaches 1920 psi (135 kg/cm 2 ), needle spring pressure is overcome.

The needle valve is lifted off its seat and allows fuel to enter the cylinder. During this process some fuel lubricates the nozzle between the needle valve and nozzle body.

AFTERGLOW & QUICK START SYSTEM

This system consists of 4 glow plugs, control module, 2 relays, glow plug resistor assembly, coolant temperature switch, clutch and neutral switches, and connecting wiring.

When ignition is "on", a "Wait-to-Start" lamp on the instrument cluster lights. When the lamp lights, relay No. 1 closes and 12 volts are applied to glow plugs. If coolant temperature is below 86°F (30°C), relay No. 2 will close. After 2 seconds, control module turns off "Wait-to-Start" lamp indicating engine is ready to be started.

If ignition is left on for more than 3 seconds without cranking, module opens relay No. 1 to prevent glow plugs from overheating. If coolant temperature is below 86°F (30°C), No. 2 relay remains closed. This applies 4.2-5.3 volts to the glow plugs through the glow plug resistor.

The control module cuts off current to glow plugs (No. 2 relay open) when coolant temperature is above 86°F (30°C), or when vehicle is under way (clutch and neutral switches closed).

Fuel Injector & Glow Plug Installation. Scheme 5

FUEL FILTER/CONDITIONER

The fuel filter/conditioner element is of 1-piece construction and cannot be cleaned. Replace filter if it becomes clogged. When the water level in the separator reaches a predetermined level, the Water-In-Diesel Fuel module will flash the oil pressure light (1-3 second rate). The separator must be drained within the next 10 miles.

Fuel Filter/Conditioner. Scheme 6

ENGINE CRANKS BUT WILL NOT START

1. Ensure correct starting procedure has been followed. Turn ignition to "RUN". Use a 12 volt test lamp to determine if voltage is available at fuel shut-off solenoid.
2. If no voltage is present, check electrical circuit. If voltage is present but solenoid does not operate, replace fuel shut-off solenoid.
3. If solenoid is OK, loosen 1 injector line nut at a time and crank engine. If fuel does not discharge, go to Fuel System Testing. If fuel discharges, go to Glow Plug Control Diagnosis.

WAIT-TO-START LAMP

1. Turn ignition to "RUN". Wait lamp should stay on for 3 seconds, then go out. If lamp lights but does not go out, replace glow plug control module. Module is located to left of steering column under instrument panel.
2. If lamp does not light, go to Glow Plug Control Diagnosis. To test wait lamp bulb, connect a jumper wire between glow plug control module terminal No. 1 and ground. (Scheme 9)
3. Turn ignition to "RUN". If wait lamp does not light, replace bulb or service or replace wiring. If wait lamp lights, circuit is OK.
4. To test power circuit, connect a 12 volt test lamp to connector terminal No. 6 and ground. Turn ignition to "RUN".
5. If test lamp lights, replace glow plug control module. If test lamp does not light, service and/or replace ignition switch or wiring.

1. Injector trouble is usually indicated by one of the following: Smoky exhaust, loss of power, misfiring, increased fuel consumption, combustion knock, or engine overheating.
2. If a faulty injector is suspected on an engine that is misfiring or puffing black smoke, test as follows. Run engine at RPM where problem is most pronounced. Momentarily loosen high pressure fuel line connection on one injector.
3. Check each cylinder in same manner. If one injector is found where loosening line makes no difference in misfiring, or black smoke stops, that injector should be checked.

1. Remove injectors from engine. Connect injector to Rotunda (14-6300) test stand.
2. Fill test stand using calibration fluid SAE No. 208629, No. J968D, or ISO 4113. Open stand valve and operate tester handle for several quick strokes to bleed air from injector.

Note. It is advisable to test the injectors before cleaning them.

Scheme 7

1. Open gauge valve and build up line pressure by slowly depressing handle until nozzle sprays fuel. Repeat operation until accurate opening pressure is established.
2. Opening pressure should be 1957-2030 psi (137.6-142.7 kg/cm 2 ). If opening pressure is not within specifications, correct by replacing adjustment shim. (Scheme 7) (Scheme 7): Exploded View of Injector Nozzle
3. Adjustment shims are available in sizes from.0197" (.50 mm) to.0606" (1.54 mm), in increments of.0016" (.04 mm). Each change in shim thickness alters opening pressure by approximately 68 psi (4.80 kg/cm 2 ).

Note. During testing, injector nozzle chatter will vary for each injector. Lack of chatter does not indicate a defective injector.

Tip Leakage

Wipe nozzle tip dry. Operate test pump to maintain pressure at 1750-1800 psi. (123-127 kg/cm 2 ). The nozzle tip should remain dry without an accumulation of fuel drops at spray holes.

Note. DO NOT wipe injector tip with fingers. This will draw fuel through injector orifice, producing a false leak.

Fuel Leak Off

Operate test pump with quick strokes and observe flow of fuel from return ports of injector. One or 2 drops per stroke is normal. If fluid squirts from fuel return port when test pump is operated, injector must be replaced.

Scheme 8

1. Operate test pump in smooth, even strokes and observe pattern of spray from tip of injector. The first 3" of spray from injector is important. Spray should be finely atomized in an even, straight pattern. (Scheme 8) (Scheme 8): Injection Nozzle Spray Pattern The first 3" of spray from end of injector is important.
2. If spray pattern is incorrect, clean injector and repeat test. See Overhaul section. After testing, disassemble injectors and clean in a decarbonizing solution or ultrasonic bath.

Glow Plug Signal

1. Place transmission selector in Neutral position. If coolant temperature is above 86°F (30°C), jumper connections at coolant switch. Turn ignition to "RUN".
2. Using voltmeter, check voltage at each glow plug lead. There must be a minimum of 11 volts at each lead for 6 seconds. After 6 seconds, voltage should drop to 4.2-5.3 volts.
3. If all glow plugs do not have a voltage signal, replace glow plug harness and repeat test. If there is no voltage, go to Engine-to-Glow Plug Harness. If voltage is OK for 6 seconds, but drops to 0 volts, go to No. 2 Glow Plug Relay Signal. If voltage is OK, go to Glow Plugs & Harness.

Engine-to-Glow Plug Harness

Unplug glow plug harness from engine harness and glow plugs. Connect a self-powered test lamp between glow plug harness connector and each glow plug terminal. If lamp does not light, service or replace harness. If lamp lights, harness is OK.

Power Circuit

1. Connect glow plug harness. Connect 12 volt test lamp between control module terminal No. 6 and ground. (Scheme 9)
2. Turn ignition to "RUN". If lamp does not light, service or replace ignition switch and/or wiring as necessary. If lamp lights, circuit is OK.

Glow Plug Control Module Connector Module is located to left of steering column on shake brace. Scheme 9

No. 1 Glow Plug Relay

1. Connect test lamp between control module terminal No. 2 (signal) and ground. Turn ignition to "RUN". If test lamp does not light, replace control module. If lamp lights for 6 seconds, control module is OK.
2. Connect test lamp between No. 1 glow plug relay terminal (located at top center of firewall under hood), and ground. Turn ignition to "RUN".
3. If test lamp does not light, check electrical harness between relay and control unit terminal No. 2. If test lamp lights for 6 seconds, module signal is OK.
4. Connect voltmeter between No. 1 glow plug relay output terminal (to glow plugs) and ground. Turn ignition to "RUN". If there is less than 11 volts, replace No. 1 glow plug relay. If there is 11 volts (or more) for 6 seconds, No. 1 relay is OK.

No. 2 Glow Plug Relay Signal

1. Connect test lamp between control module terminal No. 3 (signal) and ground. Turn ignition to "RUN". If test lamp does not light, check operation of clutch and neutral switches (step 2)). If test lamp lights, go to step 3).
2. Clutch switch is mounted on clutch pedal. Neutral switch is located on transmission. With transmission in gear and clutch pedal released, both switches should be open. With transmission in "N" and clutch pedal depressed, both switches should be closed.
3. Connect test lamp between No. 2 glow plug relay signal terminal and ground. Place transmission in "N". Turn ignition to "RUN".
4. If lamp does not light, check wiring between control module No. 3 terminal and No. 2 relay. If test lamp lights, wiring is OK.

No. 2 Glow Plug Relay

Connect test lamp between No. 2 glow plug relay output terminal (mounted on top center of firewall under hood), and ground. Turn ignition to "RUN". If test lamp does not light, replace No. 2 relay. If test lamp lights, go to Dropping Resistor.

Dropping Resistor

1. Disconnect dropping resistor (located in air intake at engine manifold) from wiring harness. Connect test lamp between dropping resistor input terminal (on wiring harness), and ground. Turn ignition to "RUN".
2. If lamp does not light, check harness between No. 2 relay and dropping resistor. If lamp lights, go to step 3).
3. Connect an ohmmeter to the connector terminals on the resistor. If reading is less than 1 ohm, dropping resistor is OK. If not, replace resistor.

Glow Plugs & Harness

1. Connect test lamp between any glow plug terminal and ground. Turn ignition to "RUN". If test lamp lights, circuit is OK. If lamp does not light, service or replace harness.
2. Disconnect lead from each glow plug. Connect 1 lead of ohmmeter to glow plug terminal and 1 lead to good ground. Meter should read less than 1 ohm. If meter reads more than 1 ohm, replace defective glow plug(s).

FUEL SYSTEM TESTING

Note. The use of diesel fuel, with a minimum cetane rating of 43, is advised.

Preliminary Checks

Visually check fuel system for leaks. Inspect the air intake system for leaks or restrictions. Check exhaust system for kinks or restriction which may affect engine performance.

Inspect injector inlet lines for kinks or restrictions. Check accelerator linkage adjustment and injection pump timing. See Adjustments. Check engine idle speed. See TUNE-UP Section.

Gauge Bar Setup

Use Rotunda Pressure Test Kit (19-0002) to diagnose fuel system problems. (Scheme 10)

Rotunda Fuel Pressure Test Kit. Scheme 10

Injection Pump Inlet Restriction

1. Connect pressure test kit. (Scheme 10) Disconnect fuel inlet at injection pump. Install adapter tee (10575) in fuel line. Connect fuel line to tee. Connect tee to vacuum gauge.
2. Run engine at 4000 RPM under no load. Vacuum should be less than 3 in. Hg. If not, check fuel lines for restrictions.

Fuel Filter Pressure Drop

1. Disconnect fuel inlet at filter/conditioner. Install adapters (5632 and 10329) in fuel line and connect vacuum gauge to tee. Run engine at 4000 RPM under no load. Gauge should read 6 in. Hg.
2. If not, disconnect fuel supply hose from tank and injection pump. Plug end of hose and pressurize line with a maximum of 15 lbs. of pressure. Apply soapy water to fuel line.
3. If bubbles are present, repair leaks in fuel line. If no leaks in line, check fuel tank and sending unit for leaks.

Fuel Contamination

Take fuel sample in a clear container. Visually examine fuel for water or dirt contamination. Replace filter/conditioner if necessary.

Air Intake Restriction

1. Remove breather hose between intake manifold and camshaft cover. Install adapter (10353) on breather nipple at intake manifold. Install cap on camshaft cover nipple. (Scheme 10)
2. Connect adapter line to H2O gauge. Run engine at 4000 RPM under no load. Restriction reading should not exceed 25 in. H2O. If more, replace filter element and check intake system for blockage.

Fuel Return Pressure

1. Remove fuel return line at injection pump. Install adapter tee (10575). Connect fuel line to tee. Connect adapter line to a vacuum/pressure gauge. Run engine at 4000 RPM under no load.
2. Maximum pressure should not exceed 2 psi (.14 kg/cm 2 ) at 4000 RPM. If pressure exceeds 2 psi (.14 kg/cm 2 ), service or replace fuel return lines.

Injection Pump Transfer Pressure

1. Remove banjo bolt from fuel return line. Install adapter (10326) in banjo fitting. (Scheme 10) Connect adapter line to 0-160 psi (0-11.25 kg/cm 2 ) pressure gauge. Run engine at 4000 RPM under no load.
2. Pressure reading should be 95-110 psi (6.7-7.7 kg/cm 2 ). If not, replace injection pump.

Crankcase Pressure Test

1. Remove breather hose from camshaft cover and plug opening. Remove oil filler cap and install adapter (10340). (Scheme 10) Connect adapter line to 0-60 in. H2O gauge.
2. Install cap (10870) on dipstick tube and cap (10872) on breather nipple of camshaft cover. Run engine at 4000 RPM, no load. Pressure should not exceed 6 in. H2O at 4000 RPM. If it does, there is internal engine problem.

COLD START DEVICE DIAGNOSIS

1. Engine must be at normal operating temperature. Rotate CSD lever clockwise to stopper. Use photoelectric tachometer (Rotunda 99-0001) to check engine RPM.
2. Engine speed must be 1450-1550 RPM. If not, check injection pump timing. (Scheme 14) Check cold start device to verify proper operation. See Cold Start Device Operation table. COLD START DEVICE OPERATION Engine Temp. °F (°C) Injection Pump Timing Engine RPM Below 45 (7) 8° BTDC 1450-1550 45-68 (7-20) 5° BTDC 1050-1350 Over 68 (20) 0° TDC 725-775
3. Apply 20 in. Hg of vacuum to CSD diaphragm. CSD lever should move 1.1" (28 mm). If not, and vacuum diaphragms are not leaking, replace injection pump.

Cold Start Thermal Switch

Remove thermal switch from thermostat housing. Check switch calibration with 20 in. Hg applied to diaphragms. See Cold Start Thermal Switch Calibration table.

COLD START THERMAL SWITCH CALIBRATION

Cold Start Device Vacuum Diagram. Scheme 11

Scheme 12

1. Turn ignition switch to "ACC" position. Ground test connector (Pin 5) at module connector. Module is located on shake brace to left of steering column. (Scheme 12) (Scheme 12): Water-In-Fuel Detector Module Connector
2. Oil pressure lamp should flash after 10 seconds (1-3 flashes per second). If not, replace module. Module is OK if lamp flashes.
3. Unplug water level sensor connector at separator and short together the 2 connectors going back to instrument panel. If (after 10 seconds) lamp does not flash, replace separator.

Lamp Flashes Continuously Or Is On Constantly

1. Unplug module connector. If lamp does not go out, check wiring harness. If lamp goes out, plug in module connector. Unplug harness at separator. If lamp stops flashing, replace separator.
2. If lamp does not go out, plug in harness at separator. Unplug Pin 2 at water-in-fuel module connector. If lamp does not go out, replace module. If lamp goes out, replace harness between module and separator.

Removal

1. Remove injection lines from injection pump and nozzles. Cap all lines and fittings. Remove nuts attaching fuel return line to injectors.
2. Remove return line and seals. Remove injectors with 27 mm socket. Remove gaskets and washers from nozzle seat.

Note. Ensure there is only 1 washer between fuel injector and cylinder head. If more than 1 washer is used, engine will have poor acceleration and rough idle.

Installation

1. Clean outside of injectors. Position new sealing gaskets with Red painted surface facing up. Position new copper washers in injector bores. Tighten to 44-51 ft. lbs. (60-70 N.m).
2. Continue installation in reverse of removal procedure. Run engine and check for fuel leaks.

Scheme 13

1. Disconnect battery ground cable. Disconnect air inlet duct from air cleaner and intake manifold. Remove rear timing belt cover and flywheel timing mark cover.
2. Rotate crankshaft until flywheel timing mark is on TDC compression stroke on No. 1 cylinder. Ensure injection pump and camshaft sprocket timing marks are aligned. (Scheme 13) (Scheme 13): Removing Injection Pump Timing Belt Injection pump and camshaft sprocket timing marks must be aligned.
3. Loosen tensioner lock nut to relieve tension on belt. Remove timing belt. Disconnect throttle cable and speed control cable. Disconnect vacuum hoses and fuel cut-off solenoid.
4. Disconnect fuel supply, return, and all injection lines. Cap all lines and fittings. Rotate injection pump sprocket until timing marks are aligned. Install 2 M8x1.25 bolts in threaded holes to hold injection pump sprocket.
5. Remove sprocket retaining nut. Remove sprocket using gear puller. Remove injection pump-to-bracket bolts. Remove pump.

1. Install injection pump on front and rear brackets. Install pump sprocket and tighten retaining nut to 51-58 ft. lbs. (70-80 N.m). Install and tighten fuel lines.
2. Install throttle and speed control cables, vacuum hoses, and fuel cut-off solenoid connector. Ensure engine is on TDC compression stroke on No. 1 cylinder.
3. Install timing belt. Align timing marks on pump and camshaft sprockets. (Scheme 13) Tighten tensioner lock nut to 15-20 ft. lbs. (20-27 N.m).
4. Timing belt tension should be 22-33 lbs. (10-15 kg) measured on side opposite tensioner. Rotate engine 2 revolutions and recheck belt tension. Install timing belt cover and timing mark cover.
5. Install air inlet duct. Connect battery cable. Bleed air from fuel system by loosening fuel line at No. 1 injector. Crank engine until a solid stream of fuel flows from the connection. Repeat for each injector.
6. Check and adjust injection pump timing. See Adjustments. Run engine and check for fuel leaks. Adjust engine idle.

1. Turn ignition switch off. Unplug module connector from water level sensor probe pigtail located on bottom of filter. Remove filter. (Scheme 6)
2. Remove water drain valve/sensor probe assembly from bottom of filter by unscrewing probe. Wipe probe with a clean cloth. Unplug sensor probe from bottom of filter.

1. Attach sensor probe pigtail to bottom of new filter element. Lubricate new "O" ring seals on water sensor probe with light film of SAE-10 motor oil. Install probe in bottom of new filter.
2. Ensure gasket sealing surface of filter adapter is clean. Lubricate filter seal with clean SAE-10 motor oil. Install filter and hand tighten.
3. Screw filter on until filter gasket just makes contact with adapter sealing surface. Finally, hand tighten filter an additional 1/2 - 5/8 turn. Connect water level sensor module.
4. Prime fuel system by pumping hand prime pump until fuel is observed in clear fuel line leading from fuel assembly to injection pump. Increased resistance to pumping should be felt. Start engine and check for leaks.

INJECTION PUMP TIMING

Note. Engine coolant temperature must be above 176° F (80°C) before injection timing can be checked and/or adjusted.

Scheme 14

Scheme 15

1. Turn ignition off. Remove distributor head plug bolt and sealing washer. Install Static Timing Gauge Adapter (Rotunda 14-0303), with metric dial indicator. (Scheme 14) (Scheme 14): Adjusting Injection Pump Timing No. 1 cylinder must be at TDC compression stroke.
2. Indicator point must be in contact with injection pump plunger. Remove timing mark cover from transmission cover. (Scheme 15) (Scheme 15): Timing Mark Location For 2.0L Diesel
3. Rotate crankshaft pulley slowly, counterclockwise, until dial indicator pointer stops moving. This will be approximately 30-50° BTDC.
4. Adjust dial indicator to zero. Turn crankshaft clockwise until crankshaft timing mark aligns with indicator pin. Dial indicator should read.04" (1 mm).
5. If reading is not within specifications, loosen injection pump attaching bolts and nuts. Rotate injection pump toward engine to advance timing and away from engine to retard timing.
6. Rotate injection pump until dial indicator reads.04" (1 mm). Tighten pump bolts and nuts to 13-20 ft. lbs. (18-27 N.m). Repeat steps 3), 4), and 5) to ensure timing is correct.
7. Remove dial indicator and adapter. Install pump distributor head plug with new sealing washer. Tighten to 10-14.5 ft. lbs. (13.5-19.5 N.m). Start engine and check idle RPM. Adjust if necessary. Check for fuel leaks.

Disassembly

Prior to disassembly, remove any excess oil or dirt from injectors. Clamp injector assembly in a soft-jawed vise. Remove nozzle holder. Remove internal parts. (Scheme 7)

Cleaning & Inspection

1. Inspect all parts for excessive wear. Inspect valve seats for carbon deposits and damage. Hold nozzle body vertically and lift needle valve up about 1/3 of its entire length and release.
2. The needle must slide to its seat by its own weight. Clean all parts in cleaning solution or sonic bath. Wash nozzle and needle valve in light oil.

Reassembly

Assemble all parts in reverse order of disassembly. Clamp nozzle in vise. Install nozzle holder.

The fuel filter/conditioner must be serviced (water purged) at each engine oil change (7500 miles) as follows

1. Ensure ignition switch is off. Place container under filter/conditioner water drain tube under vehicle. Open water drain valve on filter/conditioner 2 1/2-3 turns.
2. Pump hand prime pump located on top of filter/conditioner, 10 to 14 strokes or until all water is purged. Pump until clear diesel fuel is apparent.
3. If fuel and water will not drain from tube, open drain valve 1 more turn. Close drain valve. Start engine and check for leaks.

SPECIFICATIONS

Note. Specifications not available. Refer to specifications within appropriate REMOVAL & INSTALLATION or TESTING subject in this article.

Ford 2.0L Diesel Glow Plug System Wiring Diagram. Scheme 16

See also:
• REMOVAL & INSTALLATION