Engine Controls - Basic Testing - V6: Other Ford Probe II

Compression

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions. Compression pressures are considered within specification if the lowest reading cylinder is within 75 percent of the highest reading cylinder.

Exhaust System Backpressure

The exhaust system can be checked with a vacuum or pressure gauge. If using a pressure gauge, remove O2 sensor or air injection check valve (if equipped). Connect a 0-5 psi pressure gauge and run engine at 2500 RPM. If exhaust system backpressure is greater than 2 psi, exhaust system or catalytic converter is plugged.

If using a vacuum gauge, connect vacuum gauge hose to intake manifold vacuum port. Start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for 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. Check battery and charging system condition.
2. Check all wiring and vacuum connections.
3. Check air cleaner and ducting.
4. Check state of tune.
5. Check fuel delivery system.
6. Check cooling system.
7. Check inertia fuel shutoff switch.
8. Check for hydrostatic lock (liquid in cylinder).
9. Check fuel tank contents and fuel gauge accuracy.
10. Check for dirt, water or other contamination in fuel.
11. Check fuel lines and fittings for leaks.
12. Check fuel delivery system for proper pressure and volume.
13. Check for inoperative fuel injectors.
14. Check for improperly installed electronic equipment such as CB radio, cellular telephone or stereo.

Probe

Remove fuel pump relay or move reset switch on Inertia Fuel Shutoff (IFS) Switch. Fuel pump relay is located in engine compartment main fuse panel. The IFS switch is located on right side of trunk. Start engine and operate until it stalls. Turn ignition off. Reconnect fuel pump relay or reset IFS switch. See INERTIA FUEL SHUTOFF (IFS) SWITCH.

All Others

1. Remove fuel cap to release fuel tank pressure. Remove relief valve cap. Relief valve is located on fuel supply manifold. Using Fuel Pressure Gauge (T80L-9974-B), release fuel pressure from relief valve (Schrader valve).
2. If fuel pressure gauge is not available, disconnect electrical connector to IFS switch. For IFS switch location, see «INERTIA FUEL SHUTOFF (IFS) SWITCH»(ref-22915-S13366230902001010300000) location table under INERTIA FUEL SHUTOFF (IFS) SWITCH. Crank engine for 15 seconds to reduce system pressure.

FUEL PRESSURE

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

Scheme 149

1. Release fuel pressure. Install fuel pressure gauge. Connect a jumper wire between fuel pump test terminal at the Data Link Connector (DLC) and ground. (Scheme 149) Turn ignition on, but DO NOT start engine. This activates the fuel pump.
2. Measure and record Key On, Engine Off (KOEO) fuel pressure. Start engine. Measure and record Key On, Engine Running (KOER) fuel pressure. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(ref-123320) article. Turn ignition off and monitor fuel pressure for one minute. Fuel pressure should not drop more than 5 psi (34 kPa).
3. If fuel pressure is within specification, test is complete. If fuel pressure is not within specification, check fuel filter and lines for restriction(s). Repair or replace as necessary. If fuel pressure is still not within specification, install fuel pressure gauge (if removed). CAUTION: Inspect fuel system for leaks or damage before testing fuel pump.
4. Start engine and observe fuel pressure gauge. Gently squeeze fuel return hose. If fuel pressure increases while squeezing fuel return hose, replace fuel pressure regulator. If fuel pressure does not change while squeezing fuel return hose, check for plugged fuel inlet strainer or defective fuel pump. Repair as necessary. NOTE: For additional fuel system testing information, Proceed to appropriate SYSTEM/COMPONENT TESTS article as listed below. On EEC-IV & EEC-V equipped models, see appropriate TESTS W/CODES article as listed below for diagnostic procedure of PCM controlled fuel pump circuits. «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz) «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus) «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird) «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang) «TESTS W/CODES - EEC 2.5L»(ref-22894) (for Probe) «TESTS W/CODES - EEC-V (3.8L)»(ref-22898) (for Mustang) «TESTS W/CODES - EEC-IV (3.8L)»(ref-22897) (for Continental, Cougar, Mustang, Sable, Taurus & Thunderbird) «TESTS W/CODES - EEC-IV (3.2L SHO)»(ref-22896) (for Taurus) «TESTS W/CODES - EEC-IV (3.0L)»(ref-22895) (for Sable, Taurus, Tempo & Topaz) «TESTS W/CODES - EEC-V (3.8L)»(ref-22898) (for Mustang)

Models With EEC-V

1. Visually inspect fuel system including fuel lines, connections, injectors and electrical connections. Ensure Inertia Fuel Shutoff (IFS) switch is not tripped. Check condition of battery and fuses. Ensure fuel level in tank is sufficient.
2. Turn ignition off. Release fuel pressure. Install fuel pressure gauge. Start engine and increase engine speed to 2500 RPM. If engine will not start, cycle ignition switch several times. Record fuel pressure. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(ref-123320) article. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, proceed to appropriate SYSTEM/COMPONENT TESTS article as listed below for fuel system diagnosis. «SYSTEM/COMPONENT TESTS - EEC (2.5L)»(ref-22918) (for Probe 2.5L) «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz) «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus) «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird) «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang)
3. With fuel pressure gauge still installed, cycle ignition switch on and off several times. Record fuel pressure. If fuel pressure is at least 25 psi (172 kPa) after one minute with key off, system is capable of maintaining fuel pressure. If fuel pressure is not at least 25 psi after one minute with key off, test fuel injectors for leakage. See «FUEL INJECTORS»(ref-22915-S37335202582001010300000) .

Fuel Injector Check

1. Connect tachometer to engine. Run engine at idle. Disconnect and reconnect injectors individually. When disconnected, each injector should cause a momentary drop in engine speed of at least 100 RPM. Engine RPM drop should only be momentary as Powertrain Control Unit (PCM) 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, check idle speed. Refer to emission control specifications on decal in engine compartment. See «IDLE SPEED & IGNITION TIMING»(ref-22915-S06409297512001010300000) .

Fuel Injector Resistance

Disconnect injector harness connectors. Using digital ohmmeter, measure resistance between injector terminals. If resistance is not 11-19 ohms, replace injector.

Note. For additional testing and information, see FUEL SYSTEM in appropriate SYSTEM/COMPONENT TESTS article as listed below.

1. «SYSTEM/COMPONENT TESTS - EEC (2.5L)»(ref-22918) (for Probe 2.5L)
2. «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz)
3. «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus)
4. «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird)
5. «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang)

INERTIA FUEL SHUTOFF (IFS) SWITCH

1. If IFS switch is tripped, engine cannot be restarted until switch is manually reset. To reset IFS switch, depress switch button. For IFS switch location, see INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION table below. INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION Application Location Mustang Lower Left Rear Of Trunk Probe Right Side Of Trunk Sable & Taurus Sedan Left Side Of Trunk Wagon Behind Access Door In Right Rear Cargo Area Thunderbird, Continental, Cougar In Trunk On Left Hinge Support Or Behind Trim Panel
2. To test inertia switch, turn ignition off. Remove inertia switch. Shake inertia switch to force switch into tripped position (switch open).Measure resistance between appropriate inertia switch terminals. See «WIRING DIAGRAMS»(ref-22915-S34788972052001010300000) . Continuity should be not present between terminals with switch tripped and present when reset.

IGNITION CHECKS

Note. If an ignition failure occurs, ignition system may operate with limited ability using Failure Mode Effects Management (FMEM). When this occurs, trouble codes should be present, engine may be hard to start and dwell and timing will not change.

IGNITION COIL RESISTANCE

IGNITION COIL RESISTANCE

1. «SYSTEM/COMPONENT TESTS - EEC (2.5L)»(ref-22918) (for Probe 2.5L)
2. «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz)
3. «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus)
4. «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird)
5. «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang)

Spark Check

1. Check the EI (low data rate) system (formerly DIS) for fault codes and repair if necessary. Proceed to QUICK TEST in appropriate TESTS W/CODES article as listed below. If no fault codes are retrieved, check ignition system wiring harness connectors for corrosion and tight fit. (Scheme 150) Clean or repair connectors as necessary. «TESTS W/CODES - EEC 2.5L»(ref-22894) (for Probe) «TESTS W/CODES - EEC-IV (3.8L)»(ref-22897) (for Continental, Cougar, Mustang, Sable, Taurus & Thunderbird) «TESTS W/CODES - EEC-IV (3.2L SHO)»(ref-22896) (for Taurus) «TESTS W/CODES - EEC-IV (3.0L)»(ref-22895) (for Sable, Taurus, Tempo & Topaz) «TESTS W/CODES - EEC-V (3.8L)»(ref-22898) (for Mustang)
2. If wiring and connectors are okay, use Neon Bulb Spark Tester (D89P-6666-A) to check for spark at each spark plug wire while cranking engine. If spark is strong and consistent at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to IGNITION SYSTEMS in appropriate SYSTEM/COMPONENT TESTS article listed below. «SYSTEM/COMPONENT TESTS - EEC (2.5L)»(ref-22918) (for Probe 2.5L) «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz) «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus) «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird) «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang)

Scheme 150

1. Check the EI (high data rate) system (formerly Electronic Distributorless Ignition System - EDIS) for fault codes and repair if necessary. See QUICK TEST in appropriate article listed below. If no fault codes are present, check ignition system wiring harness connectors for corrosion and tight fit. (Scheme 151), (Scheme 152), (Scheme 153) or (Scheme 154). Clean or repair connectors as necessary. «TESTS W/CODES - EEC 2.5L»(ref-22894) (for Probe) «TESTS W/CODES - EEC-IV (3.8L)»(ref-22897) (for Continental, Cougar, Mustang, Sable, Taurus & Thunderbird) «TESTS W/CODES - EEC-IV (3.2L SHO)»(ref-22896) (for Taurus) «TESTS W/CODES - EEC-IV (3.0L)»(ref-22895) (for Sable, Taurus, Tempo & Topaz) «TESTS W/CODES - EEC-V (3.8L)»(ref-22898) (for Mustang)
2. If wiring and connectors are okay, use Neon Bulb Spark Tester (D89P-6666-A) to check for spark at each spark plug wire while cranking engine. If spark is strong and consistent at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to IGNITION SYSTEMS in appropriate SYSTEM/COMPONENT TESTS article listed below. «SYSTEM/COMPONENT TESTS - EEC (2.5L)»(ref-22918) (for Probe 2.5L) «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz) «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus) «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird) «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang)

Scheme 151

Scheme 152

Scheme 153

Scheme 154

1. Check the DI system (formerly Thick Film Ignition-IV (TFI-IV) system) for fault codes and repair if necessary. Proceed to QUICK TEST in appropriate TESTS W/CODES article listed below. If no fault codes are retrieved, check ignition system wiring harness connectors for damage, corrosion and tight fit. (Scheme 155)or (Scheme 156). «TESTS W/CODES - EEC 2.5L»(ref-22894) (for Probe) «TESTS W/CODES - EEC-IV (3.8L)»(ref-22897) (for Continental, Cougar, Mustang, Sable, Taurus & Thunderbird) «TESTS W/CODES - EEC-IV (3.2L SHO)»(ref-22896) (for Taurus) «TESTS W/CODES - EEC-IV (3.0L)»(ref-22895) (for Sable, Taurus, Tempo & Topaz) «TESTS W/CODES - EEC-V (3.8L)»(ref-22898) (for Mustang)
2. If no fault codes are retrieved and vehicle starts, problem is intermittent, go to appropriate TESTS W/O CODES article listed below. If no fault codes are retrieved and vehicle is a no-start, connect a high-output spark tester between ignition coil wire and engine ground. Check for spark at coil wire while cranking engine. A consistent Blue spark should be present. «TESTS W/O CODES - EEC 2.5L»(ref-22916) (for Probe) «TESTS W/O CODES - EEC-IV (3.8L)»(ref-22899) (for Continental, Cougar, Sable, Taurus & Thunderbird) «TESTS W/O CODES - EEC-IV (3.2L SHO)»(ref-22930) (for Taurus) «TESTS W/O CODES - EEC-IV (3.0L)»(ref-22900) (for Sable, Taurus, Tempo & Topaz) «TESTS W/O CODES - EEC-V (3.8L)»(ref-22901) (for Mustang)
3. If spark is present, go to step 4). If no spark is present, remove distributor cap and crank engine to ensure distributor rotates. If okay, check resistance of coil secondary wire. Resistance should be less than 7000 ohms per foot. Service coil wire if necessary and retest. If spark is not present, see appropriate SYSTEM/COMPONENT TESTS article as listed below or the appropriate TESTS W/O CODES article also listed below. «TESTS W/O CODES - EEC 2.5L»(ref-22916) (for Probe) «TESTS W/O CODES - EEC-IV (3.8L)»(ref-22899) (for Continental, Cougar, Sable, Taurus & Thunderbird) «TESTS W/O CODES - EEC-IV (3.2L SHO)»(ref-22930) (for Taurus) «TESTS W/O CODES - EEC-IV (3.0L)»(ref-22900) (for Sable, Taurus, Tempo & Topaz) «TESTS W/O CODES - EEC-V (3.8L)»(ref-22901) (for Mustang) «SYSTEM/COMPONENT TESTS - EEC (2.5L)»(ref-22918) (for Probe 2.5L) «SYSTEM/COMPONENT TESTS - EEC-IV (3.0L)»(ref-22927) (for Sable, Taurus, Tempo & Topaz) «SYSTEM/COMPONENT TESTS - EEC-IV (3.2L SHO)»(ref-22928) (for Taurus) «SYSTEM/COMPONENT TESTS - EEC-IV (3.8L)»(ref-22929) (for Continental, Cougar, Sable, Taurus & Thunderbird) «SYSTEM/COMPONENT TESTS - EEC-V»(ref-22914) (for Mustang)
4. On all models, if a consistent Blue spark is present at coil wire during cranking, inspect distributor cap and rotor for cracks or carbon tracking. Service as necessary and test spark output at spark plugs. If spark is present at spark plugs and engine will not start, go to appropriate TESTS W/O CODES article listed above.

Scheme 155

Scheme 156

IDLE SPEED & IGNITION TIMING

Ensure idle speed and ignition timing are set to specification. For adjustments, see the ADJUSTMENTS - V6 article.

IGNITION TIMING

Note. Ignition timing is not adjustable on models with Electronic Ignition (low or high data rate).

BASE IGNITION TIMING

IDLE SPEED

Engine idle RPM is fixed and cannot be changed by standard adjustments. A scan tool must be used because control strategy and idle speed is controlled by Powertrain Control Unit (PCM). See IDLE SPEED in the ADJUSTMENTS - V6 article.

IDLE SPEED SPECIFICATIONS

SUMMARY

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to appropriate TESTS W/CODES article as listed below. If no hard codes found in self-diag., see appropriate TESTS W/O CODES - EEC article as listed below for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

1. «TESTS W/CODES - EEC 2.5L»(ref-22894) (for Probe)
2. «TESTS W/CODES - EEC-IV (3.8L)»(ref-22897) (for Continental, Cougar, Mustang, Sable, Taurus & Thunderbird)
3. «TESTS W/CODES - EEC-V (3.8L)»(ref-22898) (for Mustang)
4. «TESTS W/CODES - EEC-IV (3.2L SHO)»(ref-22896) (for Taurus)
5. «TESTS W/CODES - EEC-IV (3.0L)»(ref-22895) (for Sable, Taurus, Tempo & Topaz)
6. «TESTS W/O CODES - EEC 2.5L»(ref-22916) (for Probe)
7. «TESTS W/O CODES - EEC-IV (3.8L)»(ref-22899) (for Continental, Cougar, Sable, Taurus & Thunderbird)
8. «3.0L V6 - VIN [U]»(ref-22887) (for Sable, Taurus, Tempo & Topaz)
9. «TESTS W/O CODES - EEC-V (3.8L)»(ref-22901) (for Mustang)

EEC-IV Wiring Diagram (Continental 3.8L - 1 Of 2). Scheme 157

EEC-IV Wiring Diagram (Continental 3.8L - 2 Of 2). Scheme 158

EEC-IV Wiring Diagram (Cougar 3.8L & Thunderbird 3.8L Except Supercharged - 1 Of 5). Scheme 159

EEC-IV Wiring Diagram (Cougar 3.8L & Thunderbird 3.8L Except Supercharged - 2 Of 5). Scheme 160

EEC-IV Wiring Diagram (Cougar 3.8L & Thunderbird 3.8L Except Supercharged - 3 Of 5). Scheme 161

EEC-IV Wiring Diagram (Cougar 3.8L & Thunderbird 3.8L Except Supercharged - 4 Of 5). Scheme 162

EEC-IV Wiring Diagram (Cougar 3.8L & Thunderbird 3.8L Except Supercharged - 5 Of 5). Scheme 163

EEC-V Wiring Diagram (Cougar 4.6L & Thunderbird 4.6L - 1 Of 5). Scheme 164

EEC-V Wiring Diagram (Cougar 4.6L & Thunderbird 4.6L - 2 Of 5). Scheme 165

EEC-V Wiring Diagram (Cougar 4.6L & Thunderbird 4.6L - 3 Of 5). Scheme 166

EEC-V Wiring Diagram (Cougar 4.6L & Thunderbird 4.6L - 4 Of 5). Scheme 167

EEC-V Wiring Diagram (Cougar 4.6L & Thunderbird 4.6L - 5 Of 5). Scheme 168

EEC-IV Wiring Diagram (Thunderbird 3.8L Supercharged - 1 Of 5). Scheme 169

EEC-IV Wiring Diagram (Thunderbird 3.8L Supercharged - 2 Of 5). Scheme 170

EEC-IV Wiring Diagram (Thunderbird 3.8L Supercharged - 3 Of 5). Scheme 171

EEC-IV Wiring Diagram (Thunderbird 3.8L Supercharged - 4 Of 5). Scheme 172

EEC-IV Wiring Diagram (Thunderbird 3.8L Supercharged - 5 Of 5). Scheme 173

EEC-V Wiring Diagram (Mustang 3.8L - 1 Of 6). Scheme 174

EEC-V Wiring Diagram (Mustang 3.8L - 2 Of 6). Scheme 175

EEC-V Wiring Diagram (Mustang 3.8L - 3 Of 6). Scheme 176

EEC-V Wiring Diagram (Mustang 3.8L - 4 Of 6). Scheme 177

EEC-V Wiring Diagram (Mustang 3.8L - 5 Of 6). Scheme 178

EEC-V Wiring Diagram (Mustang 3.8L - 6 Of 6). Scheme 179

EEC Wiring Diagram (Probe 2.5L - 1 Of 3). Scheme 180

EEC Wiring Diagram (Probe 2.5L - 2 Of 3). Scheme 181

EEC Wiring Diagram (Probe 2.5L - 3 Of 3). Scheme 182

EEC-IV Wiring Diagram (Sable 3.0L & Taurus 3.0L Except Flex Fuel & SHO - 1 Of 2). Scheme 183

EEC-IV Wiring Diagram (Sable 3.0L & Taurus 3.0L Except Flex Fuel & SHO - 2 Of 2). Scheme 184

EEC-IV Wiring Diagram (Sable 3.8L & Taurus 3.8L - 1 Of 2). Scheme 185

EEC-IV Wiring Diagram (Sable 3.8L & Taurus 3.8L - 2 Of 2). Scheme 186

EEC-IV Wiring Diagram (Taurus 3.0L Flex Fuel - 1 Of 2). Scheme 187

EEC-IV Wiring Diagram (Taurus 3.0L Flex Fuel - 2 Of 2). Scheme 188

EEC-IV Wiring Diagram (Taurus 3.0L SHO - 1 Of 2). Scheme 189

EEC-IV Wiring Diagram (Taurus 3.0L SHO - 2 Of 2). Scheme 190

EEC-IV Wiring Diagram (Taurus 3.2L SHO - 1 Of 2). Scheme 191

EEC-IV Wiring Diagram (Taurus 3.2L SHO - 2 Of 2). Scheme 192