Fuel Injection System - v6 & v8 Diesel Buick Regal II

COMPONENT TESTING

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

DESCRIPTION

Diesel mechanical fuel injection systems differ greatly from electronic fuel injection systems. In this diesel system, a mechanical high pressure rotary pump, gear driven by the camshaft at camshaft speed, injects a precisely metered amount of fuel to each cylinder at the proper time. The pump is mounted on top of the engine and provides necessary timing advance under all operating conditions.

High pressure fuel pipes (6 or 8) carry fuel from pump to an injection nozzle in each cylinder. All pipes are exactly the same length to insure that there is no variance in timing. Engine RPM is controlled by a rotary fuel metering valve. As accelerator pedal is pushed down, throttle cable opens metering valve to allow increased fuel delivery. A built-in low pressure transfer pump delivers fuel to main injection pump.

A fuel filter is located between the electric (V6) or mechanical (V8) fuel supply pump (mounted on side of engine block) and the fuel injection pump. Any excess fuel is returned to tank by a fuel return system.

AIR INDUCTION SYSTEM

An air crossover housing is located on top of engine over injection pump. It is bolted to intake manifold with 4 bolts and serves as the only air inlet in the system. No fuel passes through crossover. It is an open-chambered housing with a single inlet drawing air through an air filter assembly mounted above. Crossover unit has 2 branches, one leading to each side of intake manifold. Gaskets are installed between crossover and manifold to prevent vacuum leaks. Starter fluid should NEVER be used or sprayed into crossover. If crossover is removed, air screens must be installed.

CAV Type Diesel Injection Pump Fuel Circuit Diagram. Scheme 25

FUEL TANK-TO-PUMP SYSTEM

Diesel fuel is drawn from fuel tank by an engine mounted electric (V6) or mechanical (V8) fuel supply pump. Electric pump receives battery current when ignition switch is in "RUN" or "START" positions and puts out about 5 3/4-8 3/4 psi (.40-.62 kg/cm 2 ) to the fuel injection pump. Maximum operating current is 3 amps. Mechanical pump is driven by an eccentric cam mounted on crankshaft and puts out about 5 1/2-6 1/2 psi (.39-.46 kg/cm 2 ) to fuel injection pump.

A small screen type filter is located in fuel tank at the fuel pick-up. A larger sealed 11-12 micron fuel filter is located on rear of engine between fuel supply pump and fuel injection pump. Diesel fuel arrives at center inlet fitting on injection pump after leaving filter. A fuel return line is provided to return any excess fuel to tank.

Diesel Injection Pump (Typical). Scheme 26

DIESEL INJECTION PUMP

High pressure diesel injection pump is mounted to top of engine below air crossover. Pump is cam driven at speed equal to camshaft. Because of this, pump can precisely govern time and amount of fuel injection.

A built-in fuel pressure regulator and transfer pump picks up fuel at pump inlet, and pushes it through a passage to pump head. The pump head distributes fuel, still at transfer pump pressure of 8-12 psi (.56-.84 kg/cm 2 ), to metering valve, governor and automatic advance mechanisms. Fuel then passes to rotary fuel metering valve and into a charging passage. As pump shaft rotates, fuel is fired, under high pressure, through each delivery pipe to an injector. Pump is not serviceable and must be exchanged in case of a malfunction.

Roosa-Master Type Diesel Injection Pump Fuel Circuit Diagram. Scheme 27

FUEL DELIVERY PIPES

High pressure pipes (6 or 8) are routed from injection pump to an injector in each cylinder. Pipes are of equal length but are bent differently to achieve this equal length. Pipes are not interchangeable and are pre-bent by the manufacturer.

GLOW PLUGS

Glow plugs are small heaters provided to assist in cold starting. Glow plug controller and relay cycle 12 volts to these 6 volt heaters, which causes them to heat rapidly. After engine starts, glow plugs remain on for about a minute, then shut off. If ignition is turned on and engine is not started, glow plugs will continue to cycle until the batteries are discharged.

Diesel Glow Plug & Injection Nozzle Location. Scheme 28

INJECTION NOZZLES

One injection nozzle is located in each combustion chamber. It has a single fuel inlet fitting and is threaded into cylinder head as are glow plugs. Injection nozzles are spring loaded and calibrated to open at specified fuel line pressure. Combustion chamber end of nozzle has a replaceable copper compression seal. Inlet fitting in body of injector must be tightened to specified torque when installed or checked. (Scheme 29)

Diesel Injection Nozzle Identification Note presence and color of color band, if equipped. Scheme 29

HOUSING PRESSURE COLD ADVANCE (HPCA) SOLENOID

The HPCA is used to improve cold starting and emission control. Solenoid is controlled by engine temperature switch and advances injection timing by 3° when engine is cold. It does this by decreasing housing pressure from 10 psi (.7 kg/cm 2 ) to zero. At the same time, fast idle solenoid is activated. When temperature switch opens at 125°F (52°C), HPCA solenoid is de-energized and housing pressure rises, retarding pump timing.

WATER IN FUEL INDICATOR

Diesel vehicles are equipped with an indicator lamp to warn of water contamination in fuel tank. When water in tank nears fuel pick-up inlet, dash-mounted warning lamp will light.

STARTING INDICATOR

Lights are used to indicate when vehicle is ready to be started. A "Wait" lamp is lit when glow plugs are heating. As combustion chambers reach starting temperature, "Wait" lamp goes off, indicating that engine can be cranked to start.

DIESEL FUEL HEATER (OPTIONAL)

This option is used to heat fuel during low temperature operation, below 20°F (-7°C). This prevents wax crystals from building up and blocking fuel filters. Filter is located along right side of intake manifold and uses a resistance wire spiralled around fuel line.

Electronic Glow Plug System Diagnosis (All Models). Scheme 30

Electronic Glow Plug System Diagnosis (All Models). Scheme 31

Electronic Glow Plug System Diagnosis (all Models). Scheme 32

Electronic Glow Plug System Diagnosis (V6 Models Only). Scheme 33

Electronic Glow Plug System Diagnosis (V6 Models Only). Scheme 34

THERMAL GLOW PLUG SYSTEM DIAGNOSIS

Note. If a problem occurs when engine is cold, then engine must be cold when trouble shooting.

No Wait Lamp (Cold Engine)

1. With engine off and ignition switch in "RUN" position, check if charge light is on. If not, check gauges fuse. Check for click at glow plug relay.
2. If relay operates, check for break in Pink/Black wire between fuse block and splice. If relay does not operate, check Pink wires between ignition switch and fuse block.
3. Disconnect connector of wait lamp control relay. Using a jumper wire, connect Blue wire at connector to ground. If wait lamp does not go on, check for burned out bulb. Check for break in Blue wire between wait lamp control relay connector and wait lamp and in Pink/Black wire between wait lamp and splice.
4. Check connection at ground. Connect 1 end of test lamp to Red wire terminal of glow plug relay and other end to ground. Then touch lead to Black wire at wait lamp control relay connector. If light comes on, replace wait lamp control relay.

Wait Lamp Pulses Slowly On and Off

1. With wait lamp pulsing, connect test lamp between White and Yellow wires at wait lamp control relay. If test lamp is on when wait lamp is off and off when wait lamp is on, replace wait lamp control relay.
2. If test lamp does not come on, connect test lamp between ground and Orange wire at thermal controller. With wait lamp pulsing, check if test lamp pulses on and off with wait lamp. If test lamp still does not come on, touch to front Red wire and rear Blue and Black wire posts of glow plug relay.
3. Check for break in Red wire between batteries and glow plug relay. Also check for break in Black, Blue, Green or Orange wires between relay and thermal controller or for fault in relay.
4. If test lamp pulses with wait lamp when connected to Orange wire at thermal controller, connect test lamp between Black wire at controller and ground. If test lamp again pulses, repair Black wire between controller and ground. If not, replace controller.

Wait Lamp Stays On More Than 10 Seconds

1. Disconnect connector at diode module. Connect 1 end of test lamp to ground and other end to Red (front) post of glow plug relay. Touch test lamp lead to rear post (Blue and Black wires) of glow plug relay. Test lamp should come on if relay operates.
2. If relay operates, disconnect connector at wait lamp control relay. Wait lamp should go out. Connect test lamp between White and Yellow wires at connector.
3. If test lamp comes on, replace wait lamp control relay. If test lamp does not come on, turn off power and check for 30 ohms resistance at pins 4 and 5 of thermal controller. Replace controller if resistance is high. Check continuity of Black, Dark Green, Dark Blue, Orange/Black (Orange), Pink/Black, Brown, White, Yellow and Black wires.
4. If relay does not operate, check diesel or ECM fuse and ground. Disconnect connector at thermal controller. Connect test lamp between pins 3 and 6 at harness connector.
5. If test lamp comes on with ignition on, check continuity between pins 3 and 6. Replace controller if no continuity. If test lamp does not come on, check glow plug relay coil resistance. Replace if resistance is high. Check continuity of Pink, Pink/Black, Yellow and Black wires.

Engine Does Not Start When Cold (Wait Lamp OK) (Celebrity, Century, Ciera, & 6000 Only)

1. Check that cranking speed is 100 RPM or more. If less, check battery voltage with voltmeter (12.4 volts with ignition off). Using test lamp, check for voltage at Pink wire lead at fuel solenoid of fuel injection pump with ignition switch in "RUN" position. Repair Pink wire if no voltage.
2. If test lamp comes on, turn ignition off. Using self-powered test lamp, check for continuity through fuel solenoid to ground. If no continuity, replace fuel solenoid. With ignition switch in "RUN" position and engine off, listen for glow plug relay operation. It should click on and off.
3. If relay operates, turn ignition switch off. Disconnect all glow plug harness connectors at glow plugs. Connect self-powered test lamp between rear post (Blue and Black wires) of glow plug relay and ground. At each glow plug, touch harness connector to glow plug spade terminal.
4. If test lamp comes on, glow plug and harness lead are good. Disconnect harness connector after testing each glow plug. After testing all glow plugs, reconnect all connectors to glow plugs.
5. If test lamp does not come on, touch harness connector to ground. If lamp comes on, replace glow plug. If lamp does not come on, replace wire to glow plug. If all glow plugs are open-circuited, also replace thermal controller.
6. If relay does not operate and wait lamp went on, then off, disconnect connector at thermal controller. With ignition switch in "RUN" position, connect 1 end of test lamp to ground. Check for voltage on Brown wire. If test lamp comes on, check if coolant temperature switch is closed. If so and engine is cold, replace switch.
7. Check for voltage on Orange/Black wire. If lamp comes on, check for shorted contacts in glow plug relay. If contacts are shorted, replace relay, all glow plugs and thermal controller.
8. Connect 1 end of test lamp to positive battery cable and touch Yellow wire between controller and glow plug relay. If lamp comes on, replace thermal controller. If lamp does not come on, repair Yellow wire.

Engine Does Not Start When Cold (Wait Lamp OK) (All Other Models)

1. Disconnect Dark Blue wire from output terminal of glow plug relay to test left bank of glow plugs. Connect ammeter (60-amp minimum) between Dark Blue wire and output terminal. Set ignition switch to "RUN" position. Note ammeter reading. Normal readings for V6 engines should be about 45 amps (V8 about 60 amps).
2. Turn ignition off. Connect Dark Blue wire and test right bank of glow plugs. Disconnect Black wire from output terminal on glow plug relay. Follow procedure in step 1) to test right bank. Turn ignition off and connect Black wire.
3. If current readings are normal, glow plug system is good. Using a test lamp, check for voltage at Pink wire of fuel solenoid in fuel injection pump with ignition in "RUN" position. If no voltage, repair Pink wire.
4. If test lamp comes on, turn ignition off. Using a self-powered test lamp, check for continuity through fuel solenoid to ground. If no continuity exists, replace fuel solenoid. If continuity exists, check fuel system.
5. If current readings are 15 amps or lower, 1 or more glow plugs are not working. Disconnect individual glow plug leads on side of engine with low current reading. Connect ammeter between electrical lead and glow plug.
6. Turn ignition switch to "RUN" position. Note ammeter reading at glow plug. Current reading at each plug should be about 15 amps. Repeat test at each glow plug. Turn ignition switch off.
7. At each glow plug with low current reading, connect a test lamp between electrical connector and ground. Turn ignition switch to "RUN" position. If test lamp comes on, harness is good. Replace glow plug.
8. If test lamp does not come on, repair or replace harness. After repairing harness, repeat current test to test each glow plug.

Engine Runs Rough When Cold

1. With engine off, turn ignition switch to "RUN" position. Disconnect connector at engine temperature switch. Touch jumper wire to 2 terminals on connector. Check that fast idle solenoid extends. If not, check throttle linkage or solenoid plunger for binding. If no binding exists, replace solenoid.
2. If fast idle solenoid extends, attach tachometer and start engine. With jumper wire still connected, remove connector at cold advance solenoid of fuel injection pump. Engine speed should change 30 RPM when connector is removed. Check solenoid and fuel pump if no change.
3. Turn engine off. Using self-powered test lamp, check that engine temperature switch has continuity below 120°F (49°C) and no continuity above 120°F (49°C). Replace switch if bad.
4. Connect 1 end of test lamp to ground. With engine off and ignition switch in "RUN" position, touch other end of test lamp to Green wire pin at diode module. If lamp comes on and engine is cold, replace coolant temperature switch.
5. Turn ignition switch off. Disconnect all glow plug harness connectors at glow plugs. Connect self-powered test lamp between rear post (Blue and Black wires) of glow plug relay and ground. At each glow plug, touch harness connector to glow plug spade terminal.
6. If test lamp comes on, glow plug and harness lead are good. Disconnect harness connector after testing each glow plug. After testing all glow plugs, reconnect all connectors to glow plugs.
7. If test lamp does not come on, touch harness connector to ground. If lamp comes on, replace glow plug. If lamp does not come on, replace wire to glow plug. Check fuel system for proper fuel delivery.

No Fast Idle When Cold

1. With engine off, turn ignition switch to "RUN" position. Disconnect connector at engine temperature switch. Connect jumper wire to both terminals on harness connector. Disconnect connector at fast idle solenoid and then reconnect it, checking solenoid operation.
2. If solenoid operates, readjust for current fast idle operation. Refer to Emission Control Tune-Up Decal for specifications and adjustment procedures.
3. If solenoid does not operate on Celebrity, Century, Ciera, and 6000 models, connect 1 end of test lamp to ground and other end to White/Green lead (Black/Pink on A/C equipped models). If solenoid does not operate on all other models, connect 1 end of test lamp to ground and other end to Light Green/Black lead at solenoid.
4. On all models, if lamp comes on, disconnect connector at solenoid. Using self-powered test lamp, check continuity. Replace solenoid if no continuity exists. If lamp does not come on, touch test lamp lead to Black/Pink terminal of engine temperature switch.
5. If lamp comes on, remove connector from switch and test for continuity. Switch should be closed below 120°F (49°C) and open above 125°F (52°C). If not, replace switch.

Engine Stays on Fast Idle

1. With engine off, turn ignition switch to "RUN" position. Disconnect connector at engine temperature switch. Touch jumper wire to 2 terminals on connector. Check that fast idle solenoid extends. If not, check throttle linkage or solenoid plunger for binding. If no binds, replace solenoid.
2. Using a self-powered test lamp, check continuity of engine temperature switch. Switch should have continuity below 120°F (49°C) and no continuity above 120°F (49°C). Replace switch if bad.

Engine Continues To Run With Ignition Off

1. With ignition switch off and engine still running, disconnect connector at diode module. If engine stops, replace diode module.
2. If engine continues to run, disconnect Pink wire connector at fuel solenoid in fuel injection pump. If engine continues to run, stop engine by crimping flexible fuel return line near fuel supply pump. Repair or replace fuel solenoid.

GLOW PLUG RESISTANCE TEST

1. Start engine and allow to warm up. Remove all glow plug wires. Disconnect alternator 2-lead connector. Using idle speed screw on side of injection pump, adjust idle to roughest speed not exceeding 900 RPM. Allow engine to run for 1 minute.
2. Attach jumper wire between voltmeter ground lead and fast idle solenoid on fuel injection pump. DO NOT use any other point for ground connection. This ground connection must remain connected until all tests are completed.
3. Check resistance by touching positive lead of voltmeter to glow plug terminals (with engine running). Write down values obtained in firing order sequence (V6 - 1-6-5-4-3-2 or V8 - 1-8-4-3-6-5-7-2).
4. If ohm reading on any cylinder is about 1.2-1.3 ohms, make a compression check on that cylinder before continuing fuel injection diagnosis. Most cylinders should measure between 1.8-3.4 ohms. If more than .3 ohms difference is observed between 2 consecutive cylinders in firing order, remove injectors and check opening pressure.
5. To improve rough idle, switch nozzles as necessary. Install nozzles with a higher opening pressure to lower ohm reading, and a lower opening pressure to raise ohm reading. A change of about 30 psi (2.1 kg/cm 2 ) will vary ohm reading by .1 ohm.
6. Repeat procedure to confirm idle improvement. Be sure to check glow plug resistance at the same idle speed both times. If no improvement is observed, injection line replacement or injection pump calibration may be necessary.

INJECTION PUMP HOUSING FUEL PRESSURE

1. Engine must be at normal operating temperature. Remove air crossover assembly and install screen covers over openings in intake manifold. Remove pressure tap plug or torque screw from injector pump. To remove torque screw, add a second nut. Back screw out with both nuts attached to prevent tampering with torque screw adjustment.
2. Place seal from pressure tap plug onto pressure tap Adapter J-29382 and screw adapter into pump housing in place of plug. Screw Pressure Tap Adapter J-28526 into Pressure Tap Adapter J-29382.
3. Connect a low pressure gauge to adapter. Install magnetic pick-up tachometer. Start engine and run at 1000 RPM with transmission selector in "P". Pressure should be 8-12 psi (.56-.84 kg/cm 2 ), with no more than 2 psi (.14 kg/cm 2 ) fluctuation.
4. If pressure is zero, remove connector from housing pressure cold advance terminal. If pressure is still zero, remove injection pump cover and inspect solenoid operation. Free up solenoid if binding.
5. If pressure became normal when solenoid lead was disconnected, check operation of temperature switch on rear head bolt. Switch should open above 125°F (52°C), then close when temperature drops to 95°F (35°C).
6. If pressure is still low, replace or clean fuel return line connector assembly and return line. If pressure is too high, check fuel return system for restrictions. If fuel return line connector assembly is replaced, check injection timing.
7. Recheck pressure. If pressure is still not correct, remove injection pump for repair. Pump is not serviceable and must be exchanged for another unit. See Injection Pump Removal.
8. Remove tachometer, pressure gauge and adapter. Install a NEW pressure tap plug seal on plug or torque screw. Install tap plug or torque screw into pump. Remove screened covers from manifold. Install air crossover assembly.

Scheme 35

1. Remove injection nozzles. Refer to removal procedure under REMOVAL & INSTALLATION. Clean carbon from tip of nozzle with a soft brass brush. Check torque of inlet fitting to nozzle body and correct as necessary. (Scheme 35): Injector Nozzle Spray Patterns Keep spray contained to prevent injury to any body part.
2. Assemble nozzle to a suitable diesel injection nozzle tester using a connecting line (high pressure) 12" long by 1/4" O.D. by 1/16" I.D. between nozzle and tester. Refer to test equipment manufacturer's instructions for exact tester operating instructions. WARNING: When testing nozzles, keep spray contained to avoid serious injury. DO NOT allow injector to release line pressure on hands, arms or any part of body. Pressure of atomized test spray has sufficient penetrating power to puncture flesh.
3. Build nozzle pressure slow enough to determine exact minimum opening pressure of nozzle. Minimum opening pressure for new nozzles on V6 models is 1000 psi (70 kg/cm 2 ) without color band or with Green color band; 800 psi (56 kg/cm 2 ) on models with Red color band.
4. Minimum opening pressure for new nozzles on V8 models is 1225 psi (86 kg/cm 2 ) without color band or with White collar band. Opening pressure is about 200 psi (14 kg/cm 2 ) less for all used nozzles.
5. When nozzle releases pressure, note spray pattern and compare with examples (Scheme 35) If incorrect, or if a liquid stream, replace nozzle.
6. To test nozzle seat for leakage, decrease pressure to at least 290 psi BELOW actual opening pressure. Dry nozzle tip with compressed air, then increase pressure to 150 psi (10 kg/cm 2 ) BELOW actual opening pressure. Maintain pressure for 5 seconds and compare fuel leakage to examples (Scheme 36)
7. Replace defective nozzles, then reinstall all nozzles. Install carefully and tighten.

REMOVAL & INSTALLATION

Note. Manufacturer does not recommend disassembly of pump. However, pump cover, guide stud, and throttle shaft seals may be replaced to eliminate leaks. For all other problems, pump must be removed and taken to an authorized repair station.

Injection Nozzle Seat Tightness Check. Scheme 36

Scheme 37

1. Remove air cleaner and crossover. Install screens over air intakes. Clean injection pump cover and upper pump area. Place rags in engine valley to catch fuel. Remove fuel return pipe and control cover screws, discarding washers and gasket.
2. Remove fast idle solenoid. Scribe a line on vacuum regulator valve and pump body so valve can be reinstalled without resetting. Remove vacuum regulator valve. Disconnect throttle cable, T.V./detent cable and throttle return springs.
3. Install Tool (J-29601) over throttle shaft with slots of tool engaging vacuum return valve drive lock pin. Put spring clip of tool over throttle shaft light load advance cam and tighten wing nut. Without loosening wing nut, pull tool off shaft. This provides a reference for proper alignment during reassembly.
4. Drive roll pin (locking pin) from throttle shaft and from pump housing. Remove governor support rod, discarding "O" ring. Tilt governor carrier assembly by lifting end nearest drive end of pump and ease carrier clear of pump housing. CAUTION: DO NOT allow any dirt or foreign objects to drop into injection pump. Engine damage will result.
5. Remove clamping screw from light load cam and remove cam. Remove any burrs on end of shaft. Remove "E" circlip from throttle shaft. Pull throttle shaft out of pump. (Scheme 37) (Scheme 37): CAV Injection Pump Throttle Shaft & Seals Do not allow dirt or foreign objects to fall into pump.
6. Remove "O" rings and thrust washers from throttle shaft, noting position for reassembly. Discard "O" rings. Examine throttle shaft for wear or damage and replace if necessary. Inspect shaft bushings. If replacement is necessary, pump must be sent to authorized repair dealer.
7. Lubricate shaft and new "O" rings. Install larger "O" ring using Protector (J-33097). Slide shaft through until thrust washers can be installed on shaft in their original positions. Using Protector (J-33098), install smaller "O" ring over tapered end of protector.
8. Insert protector, tapered end first, into sleeve and slide "O" ring onto outside diameter of sleeve. Remove "cap" portion of protector. Slide sleeve with "O" ring over end of shaft. Continue sliding shaft towards opposite side of pump until shaft end is supported. Push "O" ring into shaft groove. Keep shaft horizontal and withdraw shaft enough to remove protector.
9. Slide shaft fully into housing. Place light load advance cam on shaft and insert clamping screw, but do not tighten. Install new "E" circlip into shaft recess. If new throttle shaft assembly has been installed, check shaft end play and adjust with selective thrust washers, if necessary. End play should be.006-.012" (.15-.30 mm).
10. Install new pin on shaft end. Realign advance cam in original position so Tool (J-29601) can be reinstalled over throttle shaft. Place pin in slots and spring clip over advance cam. Tighten cam screw and remove tool.
11. Rotate throttle lever forward toward drive (idling) end of pump. (Scheme 38) Tilt governor carrier assembly to place idle spring with leaf spring on governor control arm. Lower carrier into housing and engage lug on underside of throttle block with notch in throttle shaft. Lubricate governor support rod and new "O" ring. Install "O" ring on support rod using Tool (J-33096).
12. Insert plain end of governor support rod through rear of governor housing and into carrier assembly sleeve. Fully install rod into housing and install new locking pin. Install new gasket and governor control cover. Torque cover screws to 25 INCH lbs. (2.8 N.m).
13. Install fuel return lines and throttle return springs. Connect throttle and T.V./detent cables. Install vacuum regulator valve, aligning marks made during removal. Install fast idle solenoid. Start engine and check for leaks. Remove intake manifold screened covers. Install air crossover and air cleaner.

CAV Injection Pump Governor Carrier Assembly. Scheme 38

Scheme 39

Scheme 40

1. Disconnect ground cables from both batteries, then remove air cleaner and crossover. Install screens over air intakes. Disconnect fuel return line and wiring from injection pump.
2. Clean injection pump cover and area around throttle rod and guide stud. Place rags in engine valley to catch fuel. Scribe a line on vacuum regulator valve and pump body so valve can be reinstalled without resetting. Remove vacuum regulator valve. Remove throttle and T.V./detent cable (V6), throttle rod (V8) and return springs. Remove throttle cable bracket (V8).
3. Install Tool (J-29601) over throttle shaft with slots of tool engaging pin. Put spring clip of tool over throttle shaft advance cam and tighten wing nut. Without loosening wing nut, pull tool off shaft. This provides a reference for proper alignment during reassembly.
4. Drive pin from throttle shaft. Loosen clamp screw and remove advance cam and fiber washer. Remove any burrs that may have been caused by pin removal. Remove injection pump cover and remove screws from cover. CAUTION: DO NOT allow any dirt or foreign objects to drop into injection pump. Engine damage will result.
5. Note position of metering valve spring over top of guide stud. This position must be exactly duplicated during reassembly. Remove guide stud and washer, noting position for reassembly. Rotate min-max governor assembly up and remove from throttle shaft.
6. Remove throttle shaft and inspect. It may be necessary to loosen and rotate pump slightly to remove throttle shaft. If damaged or worn, replace throttle shaft. Inspect shaft bushings. If replacement is necessary, pump must be sent to authorized repair dealer. (Scheme 39): Roosa-Master Injection Pump With Advance Cam Tool Installed (Scheme 40): Roosa-Master Injection Pump With Cover Removed
7. Remove throttle shaft seals. DO NOT cut off, as a nick on shaft will cause leakage. Coat new seals lightly with grease and install on shaft.
8. Slide shaft into pump until min-max governor will slip onto throttle shaft. Rotate governor downward, hold in position, and slide throttle shaft and governor into place.
9. Install new fiber washer, throttle shaft advance cam ( DO NOT tighten screw) and new throttle shaft drive pin. Realign advance cam in original position with Tool (J-29601). Place a.005" (.13 mm) feeler gauge between fiber washer and cam. Tighten cam screw and apply locking compound.
10. Reinstall guide stud with new washer. Ensure that metering valve spring extension rides on top of guide stud. Tighten guide stud to 85 INCH lbs. (10 N.m). Overtightening of guide stud will strip aluminum threads in housing.
11. Hold throttle in idle position and install new pump cover seal. DO NOT insert screws in cover; position cover slightly forward and above pump. Carefully move cover rearward and downward into position, taking care not to damage seal.
12. Insert screws, using flat and lock washers with flat washers against pump cover. Tighten screws to 33 INCH lbs. (4 N.m). Install vacuum regulator valve, aligning marks made during removal.
13. Connect battery ground cables, turn ignition switch to "RUN" position, and touch pink solenoid wire to solenoid terminal. A clicking sound should be heard as solenoid operates. If not, remove cover and check for solenoid operation. CAUTION: If clicking sound is not heard as solenoid wire is connected, DO NOT start engine. Throttle may be stuck in wide-open position.
14. If solenoid clicks, connect all wires to pump housing. Reconnect throttle cable and T.V./detent cable (V6), throttle cable bracket and throttle rod (V8) and throttle return springs.
15. Adjust pump timing and throttle linkage. Install fuel return line and check that all fuel lines are tight. Start engine and check for leaks. Allow engine to idle for several minutes to purge air bubbles and smooth out idle. It may be necessary to stop engine for several minutes to allow air to rise and be purged.
16. Adjust vacuum regulator valve. Remove intake manifold screens. Reinstall air crossover and air cleaner.

Removal

Remove air cleaner, then remove filters and pipes from air crossover. Remove bolts and washers and lift crossover from manifold. Place screened covers over intake manifold openings.

Installation

Reverse removal procedure. Torque air crossover bolts to 24 ft. lbs. (33 N.m) on V6 models or 22 ft. lbs. (30 N.m) on V8 models. Be sure to install new gaskets between crossover and intake manifold.

1. Remove air cleaner and crossover, then install screened covers over openings in intake manifold. It is not necessary to remove pump to replace a line(s). Remove injection pump line clamps. It is not necessary to use a back-up wrench when removing lines from pump.
2. Remove injection pump lines and cap open lines, nozzles and pump fittings. Using a back-up wrench on upper injector nozzle hex, disconnect injection pump lines at nozzle inlet fittings.

1. If several lines are to be replaced, start by connecting lower lines first. Install new injection pump line(s) loosely. Position line properly. Torque all high pressure fuel lines to 25 ft. lbs. (34 N.m). Use a back-up wrench when tightening fuel lines to fuel inlet fittings on injector nozzles.
2. Install line clamps. Start engine and check for fuel leaks. Remove screened covers from intake manifold and install air crossover and air filter assembly.

1. Remove air cleaner and crossover, then install screened covers over openings in intake manifold.
2. On V6 models, remove fuel lines and fuel pump. Disconnect throttle cable and T.V./detent cable. On V8 models, disconnect throttle rod and bellcrank. On A/C equipped V8 models, remove rear compressor brace.
3. On all models, remove throttle return spring. If equipped with fuel line heater, remove line and heater fasteners. Remove throttle and T.V./detent cables from intake manifold brackets. Position cables away from engine.
4. On V8 models, remove crankcase depression regulator valve. Disconnect fuel line at fuel filter. On all models, remove fuel filter (with bracket on V8 models). Disconnect fuel return line at fuel pump.
5. Remove fuel line clamps. Disconnect lines at injection pump and cap all openings. Carefully position fuel lines out of way to gain clearance to remove pump.
6. Using special Wrench (J-26987 or equivalent), remove 2 bolts (V6) or 3 nuts (V8) securing injection pump. Remove pump and discard "O" ring between pump and adapter.

Scheme 41

Scheme 42

1. Position cylinder No. 1 at TDC by lining up crankshaft pulley mark with indicator. Line up offset tang on pump driveshaft with pump driven gear. (Scheme 41) Install new pump-to-adapter "O" ring. Install pump and fully seat by hand. (Scheme 41): Pump Driven Gear Offset at TDC (Intake Manifold Removed)
2. If new adapter (V8) or intermediate adapter (V6) is installed, set injection pump at center of slots in pump mounting flange. If original adapter (intermediate adapter) is retained, align pump timing with mark on adapter. (Scheme 42) (Scheme 42): Aligning Timing Marks on Pump & Adapter
3. Install 2 bolts (V6) or 3 nuts (V8) and lock washers securing pump and torque to 38 ft. lbs. (51 N.m) on V6 or 18 ft. lbs. (24 N.m) on V8.
4. Remove caps from all openings. Connect pump lines at nozzles and tighten to 25 ft. lbs. (34 N.m) with 2 wrenches. Install line clamps. Connect fuel return line to injection pump. Install fuel filter (with bracket on V8 models). If equipped with fuel line heater, install clamps. On V8 models, install crankshaft depression regulator valve. If equipped with A/C, install rear compressor brace.
5. On all models, install throttle and T.V./detent cables into intake manifold brackets. On V6 models, connect throttle and T.V./detent cables to pump throttle lever. Connect throttle return spring and adjust T.V./detent cable.
6. On V8 models, connect throttle rod and return spring. Adjust throttle rod. See Linkage Adjustment in this article.
7. On all models, start engine and check for leaks. Check and, if necessary, adjust pump. See Injection Timing in this article.
8. Adjust vacuum regulator valve ONLY if valve's original position is disturbed or replacement injection pump is installed. See Vacuum Regulator Valve in this article. Adjust idle speed. See Idle Speed Adjustment in this article. Remove screened covers from intake manifolds. Install air crossover.
9. Install tubes and hoses in air crossover and ventilation filters in valve covers. Install air cleaner. Reconnect EGR valve hose.

Remove air cleaner, air crossover, injection pump and lines. Remove injection pump adapter. Remove seal from pump adapter.

1. Rotate engine to place No. 1 piston at TDC. Align mark on balancer with ZERO mark on indicator. Index is offset to the right with No. 1 at TDC.
2. Apply chassis lube to seal area on adapter, taper edge and seal area on intake manifold. Install adapter and leave loose.
3. Thoroughly lube seal, inside and out, with chassis lube. Install seal on Seal Installation Tool (J-28425). Push seal onto pump adapter using installation tool.
4. Remove tool. Observe seal for proper positioning. Torque adapter bolts to 35 ft. lbs. (47 N.m) on V6 or 25 ft. lbs. (34 N.m) on V8.

Installation of New Adapter Seal. Scheme 43

Note. When working on right (rear) bank of a transverse-mounted V6 engine, intermediate steering shaft must be disconnected from rack and pinion stub shaft.

1. On transverse-mounted V6 engines, rotate intermediate steering shaft so steering gear stub shaft clamp bolt is accessible. Remove clamp bolt. Disconnect intermediate shaft from stub shaft. Remove engine support strut.
2. Place floor jack under front crossmember of engine cradle. Raise jack until car just begins to raise. Remove front 2 body mount bolts with lower cushions and retainers. Remove cushions from bolts.
3. Thread body mount bolts with retainers at least 3 turns into "cage" nuts so bolts restrain cradle movement. Slowly release jack until crossmember contacts body mount bolt retainers. Correct any interference with hoses, lines, cables and pipes as jack is being lowered. DO NOT lower cradle without restraining cradle to prevent damage to underhood items.
4. On all models, remove fuel lines from injection pump-to-nozzle on bank of engine where nozzle is to be serviced. DO NOT bend lines out of way to remove nozzle. Cap open fittings and nozzles. Remove nozzle, using wrench on largest hex of injector nozzle. Make sure copper compression seal is removed with nozzle. Protect tip of nozzle from damage and/or dirt.

1. Lubricate threads of V6 nozzles before installation. Use new copper compression seal and install nozzle. Tighten to 25 ft. lbs. (34 N.m).
2. Install fuel lines to fuel inlet fittings and using a back-up wrench on the upper hex of injector, tighten lines to 25 ft. lbs. (34 N.m).
3. On transverse V6 engines, reverse steps 1) through 3) to connect steering. On all models, start engine and check for leaks.

1. Glow plugs are mounted near each injector nozzle in the cylinder heads. They are threaded and have an electrical wire plugged into the top end.
2. Remove electrical wire from glow plug and remove plug with deep socket. Be sure to engage socket on largest diameter hex surfaces.

Install glow plug. Torque to 15 ft. lbs. (20 N.m) on V6 or 12 ft. lbs. (16 N.m) on V8. Connect electrical wire.

INJECTION TIMING

Note. 1983 Diesel model timing adjustment must be made with a Timing Meter (J-33075 or equivalent). This meter picks up engine speed and crankshaft position from the crankshaft balancer using a luminosity signal through a glow plug probe to determine combustion timing. Engine malfunctions should be corrected before a timing adjustment is made. Timing mark alignment may be used in emergency situations, but for optimum engine operation the timing meter should be used as soon as possible.

Checking

1. Place transmission selector in "P", apply parking brake and block drive wheels. Start engine and run at idle until fully warmed up. Shut off engine. NOTE: Failure to have engine fully warmed up will result in incorrect timing reading and adjustments.
2. Remove air cleaner assembly and plug air crossover using Cover (J-26996-1 or equivalent). Disconnect EGR valve hose. Clean engine probe holder (RPM counter) and crankshaft balancer rim.
3. Clean lens on both ends of glow plug probe and lens in photo-electric pick-up. Using a dulled toothpick, scrape carbon from combustion chamber side of glow plug probe. Retarded readings will result if probe is not clean.
4. Install RPM probe into crankshaft RMP counter (probe holder). Remove glow plug from cylinder No. 1 on V6 models or No. 3 on V8 models. Install glow plug probe into glow plug opening and tighten to 8 ft. lbs. (11 N.m).
5. Set timing meter offset selector to "A" (20) on V6 models or "B" (99.5) on V8 models. Connect meter leads to battery (Red to positive, Black to negative). Disconnect generator 2-lead connector. Start engine (transmission in "P") and adjust RPM to 1300 RPM on V6 engines and 1250 RPM on V8 engines.
6. Observe timing readings at 2 minute intervals. When readings stabilize, compare to specification. On V6 engines, timing should be 6° ATDC @ 1300 RPM. On V8 engines, timing should be 4° ATDC @ 1250 RPM. Timing reading, when set to specification, will be negative (ATDC).
7. Disconnect timing meter and install removed glow plug, tightening to 15 ft. lbs. (20 N.m) on V6 or 12 ft. lbs. (16 N.m) on V8. Connect generator 2-lead connector. Remove crossover cover and install air cleaner. Reconnect EGR valve hose.

Adjusting

1. Shut off engine. Note position of marks on pump flange and pump intermediate adapter (V6) or pump adapter (V8). Loosen bolts or nuts holding pump to adapter until pump can be rotated.
2. Place an offset open end wrench (1" on V6, 3/4" on V8) on boss at front of injection pump. Rotate pump to left to advance or to right to retard timing as necessary.
3. On V6 models, the width of mark on intermediate adapter is about 2/3°. On V8 models, the width of mark on adapter is about 1°. Move pump the amount that is needed and tighten pump retaining nuts to 35 ft. lbs. (48 N.m) on V6 or 18 ft. lbs. (24 N.m) on V8.
4. Start engine and recheck timing reading as outlined previously. Reset and recheck timing if necessary. On V8 models, adjust pump rod. On all models, reset fast and curb idle speeds. See appropriate TUNE-UP article.

Note. Sooty or dirty probes will result in retarded readings. The luminosity probe will soot up very fast when used in cold engine. Wild needle fluctuations on timing meter indicate a cylinder not firing properly. Correct this condition prior to timing adjustment.

LINKAGE ADJUSTMENT

Note. V6 linkage is cable operated and no adjustment is necessary.

Scheme 44

Scheme 45

1. With engine off, check pump timing. If equipped with cruise control, remove clip from cruise control throttle rod and disconnect rod from throttle lever.
2. Disconnect transmission T.V. or detent cable from throttle assembly. Loosen lock nut on pump rod and shorten by several turns. Rotate bellcrank lever to full throttle position and hold.
3. Lengthen rod until injection pump lever just contacts full throttle stop. Release bellcrank assembly and tighten pump rod lock nut. (Scheme 44): Disassembled View of V8 Throttle Linkage (Scheme 45): Transmission T.V. or Detent Cable Adjustment
4. Reconnect transmission T.V. or detent cable. Depress and hold metal lock tab on upper end of cable. Move slider away from lever assembly until it stops against metal fitting. Release metal tab.
5. Install cruise control servo rod (if equipped). Rotate bellcrank lever assembly to full throttle stop and release lever assembly. Adjust vacuum regulator valve. See Vacuum Regulator Valve in this article. Adjust idle speed. See appropriate TUNE-UP article.

Scheme 46

1. Remove air crossover and install screen covers over openings. On V6 models, disconnect throttle and T.V./detent cables from pump throttle lever. On V8 models, disconnect throttle rod from pump. (Scheme 46): Vacuum Regulator Valve Adjustment
2. Loosen vacuum regulator valve-to-pump bolts. Install carburetor angle gauge to injection pump throttle lever. Rotate throttle lever to wide-open throttle position and set angle gauge to zero degrees, then center bubble.
3. Set angle gauge to 49° (V6) or 58° (V8). Rotate throttle lever until bubble is centered. Attach vacuum pump to port "A" of vacuum regulator valve and vacuum gauge to port "B". (Scheme 47)
4. Apply 18-24 in. Hg vacuum to port "A", then rotate vacuum valve clockwise to obtain 10.6 in. Hg. Tighten bolts and remove vacuum gauge, pump and angle gauge.
5. Connect throttle and T.V./detent cables (V6) or throttle rod to pump lever (V8). Remove screen covers on intake manifold. Install air crossover.

Vacuum Regulator Valve Port Locations. Scheme 47

Glow Plug System Wiring Diagram (Electronic Type - V6). Scheme 48

Glow Plug System Wiring Diagram (Thermal Type - V6). Scheme 49

Glow Plug System Wiring Diagram (Electronic Type - V8). Scheme 50

Glow Plug System Wiring Diagram (Thermal Type - V8). Scheme 51