Engine Controls - Basic Testing Mercury Topaz II

INTRODUCTION

The following diagnostic steps can help you prevent overlooking a simple problem and start diagnosis for a no-start condition.

The first step in diagnosing any driveability problem is to verify that the problem exists. This may be accomplished by test driving the vehicle under the same conditions during which the problem reportedly occurs.

Prior to entering self-diagnostics, a careful and complete inspection of several systems is required. Most driveability or no-start problems are not related to computerized engine control systems, but are in fact simple mechanical, electrical, fuel or vacuum related faults. Most engine control problems are the result of mechanical breakdowns, poor electrical connections, or damaged or misrouted vacuum hoses.

Before considering the computer system as a possible cause of problems, check ignition high tension wires, fuel supply, electrical connections and vacuum hoses. Failure to do so may result in improper diagnosis or lost diagnostic time.

Note. All voltage tests should be performed with a Digital Volt Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated otherwise in testing procedures.

VISUAL INSPECTION

Perform a visual inspection of all electrical wiring. Look for chafed, stretched, cut or pinched wiring. Inspect electrical connectors and connections for tight fit and corrosion. Repair as necessary. Inspect all vacuum hoses for proper routing, cuts or pinches. If necessary, see VACUUM DIAGRAMS article to verify routing and connections. Repair as necessary. Inspect air induction system for possible vacuum leaks.

Compression

Engine mechanical condition can be checked using a compression gauge, vacuum gauge or an engine analyzer capable of performing a relative compression test. See engine analyzer instruction manual for availability and description of relative compression feature.

Exhaust System Backpressure

The exhaust system can be checked with a vacuum gauge or a pressure gauge. Remove O2 sensor or air injection check valve (if equipped). Connect a 1-10 psi gauge and run engine at 2500 RPM. If exhaust system backpressure is greater than 1 3/4-2 psi, exhaust system or catalytic converter is plugged.

If a vacuum gauge is used, connect it to intake manifold vacuum and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after RPM has stabilized, exhaust system should be checked for a restriction.

PRELIMINARY CHECKS

Check that the following systems and components are in good condition and operating properly before diagnosing problems in fuel injection system

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

ENGINE DOES NOT CRANK - TROUBLE SHOOTING

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

ENGINE CRANKS BUT WILL NOT START - TROUBLE SHOOTING

1. Check fuel tank contents and fuel gauge accuracy. Check for dirt, water or other contamination in fuel.
2. Check ignition system for strong secondary current at spark plugs. If no spark exists or is weak, repair ignition system problem first.
3. Check fuel lines and fittings for leaks. If no leaks are found, check fuel delivery system for proper pressure and volumes. Reset inertia switch if necessary.
4. Check for a defective fuel injector or coolant temperature sensor. Ensure that TPS is not sticking.

FUEL PRESSURE CHECK

FUEL PUMP PRESSURE (PFI SYSTEMS)

Note. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article.

1. On 2.2L & 2.2L Turbo models, relieve fuel line pressure by disconnecting fuel pump relay and starting engine. After engine stalls, turn ignition off. Reconnect fuel pump relay.
2. On all other models, remove fuel tank cap. Using Fuel Pressure Gauge (T80L-9974-B), release pressure from system at pressure relief valve (Schrader valve) on fuel injection manifold rail.
3. The fuel pump may be activated by grounding the fuel pump lead at the SELF-TEST connector. Use a jumper lead and ground the "FP" terminal with the ignition on. This activates the fuel pump. (Scheme 115) For additional circuit test information, see appropriate TESTS W/CODES article in this section.

Scheme 115

FUEL PRESSURE (CFI SYSTEMS)

Note. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article.

1. Disconnect wiring at inertia switch. Inertia switch is located behind trim panel in right rear side of cargo area on Sable and Taurus station wagons and behind trim panel on left side of trunk on all other models. Crank engine for at least 15 seconds to reduce system fuel pressure.
2. Disconnect fuel supply line at throttle body. Install In-Line Adapter (D85L-9974-B) and Fuel Pressure Gauge (T87L-9974-A) on throttle body. Reconnect inertia switch and start engine. Check fuel pressure at idle and when accelerating engine. Pressure should remain stable through entire period of acceleration.
3. If gauge readings are correct, disconnect inertia switch. Crank engine for 15 seconds to reduce fuel pressure. Remove gauge and in-line adapter. Install original fuel line and connect inertia switch. Start engine and check for fuel leaks.

INJECTOR RESISTANCE (CFI)

To measure injector resistance, disconnect injector harness connector. Set ohmmeter on 10-ohm scale. Ensure injector resistance is within specification. See CFI INJECTOR RESISTANCE table.

CFI INJECTOR RESISTANCE

PFI INJECTOR CHECK

1. Connect tachometer to engine. Run engine at idle. Disconnect and reconnect injectors individually. If each injector causes a momentary drop in engine speed of at least 100 RPM, injectors are giving proper fuel delivery. RPM drop should only be momentary as ISC will attempt to re-establish correct idle RPM.
2. Replace any injectors that do not cause sufficient drop in engine speed. When test is complete, turn engine off. To check curb idle, refer to emission control specifications on decal in engine compartment or IDLE SPEED & IGNITION TIMING in this article.

PFI INJECTOR CIRCUIT

Disconnect all injector harness connectors. Using digital ohmmeter, check resistance across terminals of each injector. See INDIVIDUAL PFI INJECTOR RESISTANCE table. Disconnect injector bank harness connector and check resistance of injector bank. See PFI INJECTOR BANK RESISTANCE table. Repair wiring or any injector not within specification.

INDIVIDUAL PFI INJECTOR RESISTANCE

PFI INJECTOR BANK RESISTANCE

Note. For further component testing and information, see appropriate TESTS W/CODES article in this section.

INERTIA SWITCH

1. In event of a collision, electrical contacts in inertia switch open and fuel pump automatically shuts off. Fuel pump will shut off even if engine does not stop running. Engine will stop due to lack of fuel. CAUTION: DO NOT reset inertia switch until fuel system has been inspected for leaks.
2. It is not possible to restart engine until inertia switch is manually reset. To reset inertia switch, depress button on switch. On Crown Victoria and Grand Marquis station wagon models, switch is located in left rear side storage compartment. On RWD vehicles (except wagons), inertia switch is located in trunk, on left hinge support or behind trim panel. On Sable and Taurus, inertia switch is located on left side of trunk (except station wagon). On Taurus and Sable station wagon models, switch is located behind access door in right rear cargo area. On all other vehicles, inertia switch is located in trunk, on left hinge support or behind trim panel.

SPARK CHECK

1. Using a high output spark tester, check for spark at coil wire. If spark is present, go to step 2). If spark is not present, remove distributor cap and crank engine to check for distributor rotation. If okay, check coil secondary wire resistance. Resistance should be no greater than 7000 ohms per foot.
2. With spark tester attached, cycle on and off 2-3 times. Spark should occur each time ignition is cycled. If spark is not present, go to step 3). If spark is present, inspect ignition components for wear or damage and service as necessary. Ensure distributor armature to sleeve roll pin is secure. Verify that Orange and Purple wires between distributor and ignition module ARE NOT CROSSED.
3. Turn ignition off. With ignition module connector attached, insert straight pin in Red wire. Ensure pin DOES NOT contact ground. Turn ignition on. Measure battery voltage. Measure voltage at straight pin. Straight pin voltage should be at least 90 percent of battery voltage. If not, check ignition switch and circuitry for wear or damage. Repair as necessary.
4. If battery voltage at straight pin is 12 volts, remove ignition coil and module connector. Inspect connector terminals and wiring. With an ohmmeter, measure resistance between ignition coil BAT terminal and ignition module harness connector Red wire. Resistance should be 0.8-1.6 ohms. If resistance is okay, replace ignition module. If not, replace ballast resistor.

Scheme 116

1. Using a high output spark tester, check for spark at coil wire while cranking engine. If spark is present, go to step 2). If spark is not present, remove distributor cap and crank engine to check for distributor rotation. If okay, check coil secondary wire resistance. Resistance should be no greater than 7000 ohms per foot.
2. Place transmission in Neutral. Disconnect TFI wiring harness connector. Attach TFI Ignition Tester (105-000002). Connect Red lead of tester to 12 volts. Attach remote starter to "S" terminal of starter relay. Crank engine with remote starter while observing 2 LED lights on tester. If the PIP light blinks, go to step 4). If not, remove distributor.
3. Remove TFI module from distributor. Using an ohmmeter, ensure all circuit resistance values are correct. See TFI CIRCUIT SPECIFICATIONS table. If readings are correct, replace stator. If readings are incorrect, replace TFI module. TFI CIRCUIT SPECIFICATIONS TFI Terminals Ohms GND-PIP More than 500 PIP PWR-PIP IN Less than 2000 PIP PWR-TFI PWR Less than 200 GND-IGN GND Less than 2 PIP IN-PIP Less than 200
4. If the TACH light did not blink in step 2), replace TFI module and repeat step 1). If spark is still not present, replace ignition coil and module connector. If the TACH light did blink in step 2), substitute ignition coil with a known working unit and repeat step 1). If spark is present, verify coil secondary wire resistance is greater than 7000 ohms per foot. Replace ignition coil.
5. If spark was not present in step 4), connect original vehicle coil and spark tester. Remove pin-in-line connector located near distributor. Crank engine while checking for spark. If spark is present, inspect PIP and ignition ground circuits to verify continuity. (Scheme 118)and (Scheme 119). Repair as necessary.
6. If spark was not present in step 5), measure battery voltage. Measure voltage at ignition coil positive (+) terminal. Ignition coil positive (+) terminal voltage should be at least 90 percent of battery voltage. If not, check circuitry between ignition coil and ignition switch for wear or damage. Repair as necessary.
7. If ignition coil positive (+) terminal voltage was at least 90 percent of battery voltage in step 6), remove connector from ignition module. Disconnect starter relay "S" terminal. Turn ignition on. Measure voltage at ignition module connector terminals. (Scheme 117) Voltage should be at least 90 percent of battery voltage.
8. If not, check circuitry between ignition coil and ignition switch for wear or damage. Repair as necessary. If voltage was at least 90 percent of battery voltage in step 7), inspect wiring between ignition module terminal No. 2 and coil. If okay, check all related circuitry. Replace or repair as necessary.

Scheme 117

TFI CIRCUIT SPECIFICATIONS

Scheme 118

Scheme 119

1. Check ECA for fault codes and repair if necessary. See appropriate TESTS W/CODES article in this section. If no fault codes are retrieved, use Neon Bulb Spark Tester (D89P-6666-P) to check for spark at each spark plug wire. If spark is not present, check spark plugs and spark plug wires for wear or damage. Repair or replace if necessary.
2. Turn ignition off. Install DIS Diagnostic Cable (007-00044). (Scheme 119) Attach diagnostic cable to EEC-IV Breakout Box (T83L-50-EEC-IV). With 3.0/3.8 overlay in place, connect LED test light between breakout box terminal No. 33 and No. 60. Crank engine.
3. If test light does not blink during cranking, replace crankshaft sensor and repeat test. If test light does blink during cranking, turn ignition off. Disconnect EEC-IV wire harness connector. Disconnect diagnostic cable connector from DIS module. Using an ohmmeter, measure resistance between EEC-IV connector terminal No. 56 and breakout box terminal No. 33.
4. Also measure resistance between EEC-IV connector terminal No. 16 and breakout box terminal No. 55. Resistance for both circuits should be less than 5 ohms. If not, repair as necessary and repeat test. If resistance is okay, test is complete. For more diagnostic procedures, see appropriate PIN VOLTAGE CHART S article in this section.
5. With diagnostic cable and breakout box installed, connect LED test light between breakout box terminal No. 2 and No. 5. If test light is not on, check connectors and circuitry and repair as necessary. If test light is on, turn ignition off.
6. Connect ohmmeter between breakout box terminals No. 2 and No. 60. If resistance is more than 5 ohms, check DIS module mounting screws for clean, tight connection. Repair as necessary. If okay, replace DIS module.

DIS COIL PACK CHECK

1. With diagnostic cable breakout box installed, connect LED test light between the following breakout box terminals: No. 3 (Coil 1 Drive) and No. 60 (BAT -). No. 18 (Coil 2 Drive) and No. 60 (BAT -). No. 6 (Coil 3 Drive) and No. 60 (BAT -).
2. If test light is on for all checks, go to PIP TO DIS MODULE CHECK. If test light is not on for all checks, remove diagnostic cable. Turn ignition off. Connect jumper wire between breakout box terminals No. 2 and No. 60. Repeat step 1).
3. If test light is on for all checks, replace DIS module. If test light is not on for all checks, connect diagnostic cable to DIS module pins No. 7 and No. 12. Connect LED test light between breakout box terminals No. 7 and No. 60. Turn ignition on.
4. If test light does not come on, check electrical connectors and circuitry. Repair as necessary. If test light comes on, connect LED test light between the following breakout box terminals: 3.0L SHO No. 12 (Coil 1 at coil) and No. 60 (BAT -). No. 13 (Coil 3 at coil) and No. 60 (BAT -). No. 14 (Coil 2 at coil) and No. 60 (BAT -). 3.8L Thunderbird Supercoupe No. 12 (Coil 2 at coil) and No. 60 (BAT -). No. 13 (Coil 3 at coil) and No. 60 (BAT -). No. 14 (Coil 1 at coil) and No. 60 (BAT -).
5. Turn ignition on. If test light comes on for all 3 checks, check electrical connectors and circuitry. Repair as necessary. If test light does not come on, turn ignition off. Remove diagnostic cable from coil pack.
6. Connect jumper wire between breakout box terminals No. 7 and No. 57. Repeat step 4). If test light comes on for all 3 checks, check electrical connectors and circuitry. Repair as necessary. If test light does not come on for all 3 checks, replace coil pack.

Scheme 120

PIP TO DIS MODULE CHECK

1. Connect LED test light between breakout box terminals No. 32 and No. 60. Crank engine while observing test light. If test light does not blink while engine is cranking, go to EEC-IV PROCESSOR SPOUT CIRCUIT CHECK step 3).
2. If test light blinks while engine is cranking, connect test light between breakout box terminals No. 36 and No. 60. If test light does not blink while engine is cranking, go to EEC-IV PROCESSOR SPOUT CIRCUIT CHECK.
3. If test light blinks while engine is cranking, connect LED test light between the following breakout box terminals: No. 3 (Coil 1 Drive) and No. 60 (BAT -). No. 18 (Coil 2 Drive) and No. 60 (BAT -). No. 6 (Coil 3 Drive) and No. 60 (BAT -). If test light blinks for all 3 checks, replace coil pack.
4. If test light does not blink for all 3 checks, turn ignition off. Remove diagnostic cable connector from coil pack connector. Connect LED test light between the following breakout box terminals: No. 3 (Coil 1 Drive) and No. 60 (BAT -). No. 18 (Coil 2 Drive) and No. 60 (BAT -). No. 6 (Coil 3 Drive) and No. 60 (BAT -).
5. Turn ignition on. If test light comes on for any of the 3 checks, check electrical connectors and circuitry. Repair as necessary. If test light does not come on for any of 3 checks, replace DIS module.

EEC-IV PROCESSOR SPOUT CIRCUIT CHECK

1. With ignition off, remove EEC-IV processor wire harness connector. Connect LED test light between breakout box terminals No. 36 and No. 60.
2. Crank engine while observing test light. If test light blinks while engine is cranking, replace EEC-IV processor. If test light does not blink while engine is cranking, turn ignition off.
3. Remove diagnostic cable connector from DIS module. Connect LED test light between breakout box terminals No. 36 and No. 60. Turn ignition on. If test light comes on, check for SPOUT short to VBAT. (Scheme 119)
4. If test light does not come on, connect LED test light between breakout box terminals No. 36 and No. 57. Turn ignition on. If test light comes on, check for SPOUT short to ground. If test light does not come on, replace DIS module.

DIS MODULE PIP CIRCUIT CHECK

1. Turn ignition off. Remove diagnostic cable connector from DIS module. Connect LED test light between breakout box terminals No. 32 and No. 60. Crank engine while observing test light.
2. If test light blinks while engine is cranking, replace DIS module. If test light does not blink while engine is cranking, turn ignition off. Connect LED test light between breakout box terminals No. 2 and No. 56.
3. If test light does not come on, check electrical connectors and circuitry. Repair as necessary. check for SPOUT short to ground. If test light does come on, turn ignition off. Using an ohmmeter, measure resistance between breakout box terminals No. 2 and No. 55.
4. If resistance is more than 5 ohms, check connectors and circuitry and repair as necessary. If resistance is less than 5 ohms, connect LED test light between breakout box terminals No. 2 and No. 35. Crank engine while observing test light.
5. If test light blinks while engine is cranking, check connectors and circuitry and repair as necessary. If test light does not blink while engine is cranking, turn ignition off. Remove diagnostic cable from crankshaft sensor. With diagnostic cable connector removed from DIS module, connect LED test light between breakout box terminals No. 35 and No. 57.
6. Turn ignition on. If test light comes on, check for short in PIP circuit between DIS module and crankshaft sensor. If test light does not come on, connect LED test light between breakout box terminals No. 35 and No. 60. Turn ignition on.
7. If test light comes on, PIP circuit is shorted to VBAT between DIS module and crankshaft sensor. If test light does not come on, turn ignition off. Disconnect EEC-IV processor from vehicle harness. Connect LED test light between breakout box terminals No. 33 and No. 57.
8. Turn ignition on. If test light comes on, check connectors and circuitry and repair as necessary. If test light does not come on, connect LED test light between breakout box terminals No. 33 and No. 60. Turn ignition on.
9. If test light comes on, check connectors and circuitry and repair as necessary. If test light does not come on, verify crankshaft vane moves through sensor air gap when engine is cranked. If okay, replace crankshaft sensor.

Scheme 121

IGNITION COIL RESISTANCE

IGNITION COIL RESISTANCE SPECS - OHMS @ 75°F (24°C)

IDLE SPEED & IGNITION TIMING

Ensure idle speed and ignition timing are set to specification. For correct adjustment procedures, refer to the appropriate ADJUSTMENTS article. Ensure all accessories are off and transmission is in Park or Neutral. Set parking brake. Disconnect automatic parking brake release (if equipped). Vehicle front wheels are in straight-ahead position and curb idle speed set to specification.

4-CYLINDER IGNITION TIMING SPECIFICATIONS

4-CYLINDER BASE IGNITION TIMING

4-CYLINDER COMPUTED IGNITION TIMING

4-CYLINDER IDLE SPEED SPECIFICATIONS

4-CYLINDER BASIC IDLE RPM SPECIFICATIONS

V6 IGNITION TIMING SPECIFICATIONS

V6 BASE IGNITION TIMING

V6 COMPUTED IGNITION TIMING

V6 IDLE SPEED SPECIFICATIONS

V6 BASIC IDLE RPM SPECIFICATIONS

V8 IGNITION TIMING SPECIFICATIONS

V8 BASE IGNITION TIMING

V8 COMPUTED IGNITION TIMING

V8 IDLE SPEED SPECIFICATIONS

V8 BASIC IDLE RPM SPECIFICATIONS

IDLE MIXTURE ADJUSTMENT

Note. No idle mixture adjustments are possible on any models. See appropriate TESTS W/CODES article for diagnosis of incorrect idle mixture.

THROTTLE POSITION SENSOR (TPS) ADJUSTMENT

Two types of TPS are used on EEC-IV system. "Level C" type is adjustable and "Level D/RD" type is non-adjustable. Throttle position sensors without slotted mounting holes are not adjustable. Voltage reading on non-adjustable TPS is .75 volts at idle and greater than 4.5 volts at wide open throttle. Replace throttle position sensor if not within specification.

INTERCOOLER

Supercharged Thunderbird and Cougar vehicles are equipped with an intercooler, mounted next to the radiator. The intercooler cools the pressurized air from the supercharger, increasing the air density, which improves combustion efficiency, engine horsepower and torque.

At low throttle, the engine runs under vacuum due to normal intake restrictions. To prevent supercharger cavitation, reduced engine performance and increased temperatures, a vacuum-controlled bypass valve is installed at the supercharger outlet. The bypass valve allows a controlled amount of airflow from the supercharger outlet back into the supercharger. As the throttle opening is increased, the actuator closes the bypass valve, directing all air from the supercharger to the intake manifold. This occurs as soon as the throttle opens, resulting in immediate response.

Note. It is not possible to increase manifold pressure or engine power output by alerting the bypass valve or the actuator.

LUBRICATION

The supercharger has a self-contained oiling system that does not require a fluid change for the life of the vehicle. However at 30,000 mile interval, the supercharger fluid level should be checked. The vehicle should be parked on a level surface, the engine cool, and not running. To check the oil, remove the Allen head plug located at the front of the supercharger. The oil level should be at the bottom of the fill plug threads when cold. If the fluid level is low, add a synthetic supercharger fluid that meets ESE-M99C115-A. such as E9SZ-19577-A or equivalent.

OPERATION

The supercharger system is a blow-through type with the fuel injected directly into the intake ports. The supercharger is a belt driven off the crankshaft through the idler pulley. The throttle body controls the amount of intake air to the supercharger through the inlet plenum. Air from the supercharger is routed through the intercooler, then to the intake manifold. The resulting denser air charge in the combustion chamber provides for a high power output of the engine over a non-supercharged engine of the same displacement.

At partial-throttle opening or when vacuum is present in the intake system, a vacuum controlled bypass valve reroutes some discharged air from the supercharger back through the intake plenum. This prevents the supercharger from cavitating, causing reduced performance, increased temperatures, and poor economy.

Scheme 122

SUPERCHARGER DIAGNOSIS. Scheme 123

Induction System Leak

Air induction system leaks can make the entire engine run too lean. This condition will be most apparent at idle, causing rough idle and/or stalling at idle. This may also result in Self-Test Code 41 and 91 (system always lean). Tests to locate induction system leaks, use propane.

1. Visually inspect all flange joints for indications of leaks.
2. Connect an EEC-IV Tester to read the rich/lean state of the EGO sensors.
3. Bring engine to normal operating temperature.
4. With engine idling in Neutral or Park and parking brake engaged, spray small amounts of propane around the following possible sources of air leaks: Flange joint at rear of supercharger. Bypass hose connections at rear of supercharger. Flange joint at supercharger outlet adapter. Four Tube which joints at supercharger outlet to upper tube, upper intercooler inlet, lower intercooler inlet, intake manifold adapter inlet. Intake manifold adapter to intake manifold flange.
5. When propane is sprayed near an induction system air leak, the EGO monitor box will indicate "RICH" for one or two seconds, then return to normal switching. When the propane is removed from the leak, the EGO monitor box will indicate "LEAN" after one or two seconds.
6. If a leak is found, retighten the nuts at all tube flange locations and the supercharger outlet adapter "collar". See MINI-SEALING PROCEDURE below.
7. If a leak is still present, the entire induction system must be disassembled. See REMOVAL & INSTALLATION in this article below. If no leak is found see appropriate TESTS W/CODES article in this section.

Intercooler Tube Connections

For leaks at joint between intercooler and inlet or outlet tube, do the following steps below.

1. Slightly loosen nut retaining inlet tube to alternator-power steering pump bracket.
2. Tighten nuts at intercooler flanges to 15-22 ft.lbs. (20-30 N.m).
3. Tighten nut at alternator-power steering pump bracket to 30-40 ft.lbs. (40-55 N.m).
4. Recheck all joints with propane.

Supercharger Outlet Adapter/Tube Connection

For leaks at supercharger outlet adapter collar and inlet tube joint, do the following steps below.

1. Slightly loosen nut retaining inlet tube to alternator-power steering pump bracket.
2. Tighten collar to 148 ft.lbs. (200 N.m).
3. Wait 10 minutes minimum and retighten collar to 148 ft.lbs. (200 N.m). NOTE: When compressed, the sealant tape flows and forms to the sealing surface. If the collar is not retorqued, the torque of the collar will drop causing a leak at this joint.
4. Tighten nut at alternator-power steering pump bracket to 30-40 ft.lbs. (40-55 N.m).
5. Recheck all joints with propane.

Intake Elbow Adapter/Outlet Tube Connection

For leaks at intake elbow adapter to outlet tube joint, do the following steps below.

1. Slightly loosen nut retaining outlet tube to alternator-power steering pump bracket.
2. Loosen bolt retaining outlet tube to cylinder block support bracket bottom.
3. Tighten nuts at intake elbow adapter to 15-22 ft.lbs. (20-30 N.m).
4. Tighten nut at alternator-power steering pump bracket to 30-40 ft.lbs. (40-55 N.m).
5. Tighten bolt retaining outlet tube to cylinder block support bracket to 30-40 ft.lbs. (40-55 N.m).
6. Recheck all joints with propane.

SUPERCHARGER ASSEMBLY REMOVAL & INSTALLATION

Note. The supercharger is serviced by replacement only.

Removal

1. Disconnect battery ground cable.
2. Remove throttle body air inlet tube.
3. Remove cowl vent screens.
4. Partially drain cooling system.
5. Disconnect RH side plug wires at coil assembly, and position out of the way. Disconnect electrical connections at the air bypass valve, throttle position sensor and air charger temperature sensors.
6. Disconnect vacuum lines from the inlet/plenum assembly. Remove the EGR tranducer from the bracket and disconnect vacuum line. Disconnect PCV tube.
7. Disconnect throttle linkage at throttle housing. Remove linkage bracket attaching bolts and position bracket out of the way. Disconnect speed control (if equipped).
8. Remove two EGR valve attaching bolts and move EGR valve away from intake assembly (if equipped).
9. Disconnect coolant hoses from throttle body.
10. Remove supercharger drive belt.
11. Remove intercooler inlet and outlet tubes as outlined.
12. Remove three intake elbow retaining bolts.
13. Remove three supercharger retaining bolts.
14. Lift supercharger and intake elbow assembly from vehicle as a unit.

Installation

1. Clean and inspect all gasket surfaces.
2. Position new gasket on intake manifold using guide pins, if available.
3. Install supercharger, throttle body and intake elbow as an assembly.
4. Tighten two 8mm bolts to 15-22 ft.lbs. (20-30 N.m). Tighten 12mm bolt to 52-70 ft.lbs. (70-95 N.m).
5. Install three intake elbow retaining bolts. Tighten to 20-28 ft.lbs. (26-38 N.m).
6. Install intercooler tubes as outlined.

Scheme 124

SUMMARY

If no faults were found while performing BASIC TESTS, proceed to the appropriate TESTS W/CODES article. If no hard codes are found in self-diagnostics, proceed to the appropriate TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.), or intermittent diagnosis procedures.

See also:
• FUEL PRESSURE SPECIFICATIONS