Tune-Up - 4-cyl Ford Cab & Chassis Ranger

ENGINE IDENTIFICATION

Eighth character of Vehicle Identification Number (VIN) identifies engine. VIN is stamped on metal tab, attached to upper left side of instrument panel and is visible through windshield. VIN can also be found on Safety Standard Certification Label attached to left door lock edge.

VIN ENGINE CODES

TUNE-UP NOTES

Note. When performing tune-up procedures described in this article, following notes and precautions must be followed.

When performing tune-up on vehicles equipped with catalytic converter, do not allow or create condition of engine misfire in one or more cylinders for an extended period of time. Damage to converter may occur due to loading with unburned air/fuel mixture.

When connecting a tachometer to Dura-Spark ignition coil, install the alligator clip on tachometer into the "DEC" (Tach Testing) cavity. If any spark plug wire is disconnected with this system, connection must be first greased with silicone grease before it is reattached.

Due to production changes, always refer to Engine Tune-Up Decal in engine compartment before attempting tune-up. In the event of conflict between specifications given in this manual and decal specifications, use decal specifications.

SPARK PLUGS

SPARK PLUG TYPE

SPARK PLUG SPECIFICATIONS

HIGH TENSION WIRE RESISTANCE

1. Remove wire from ignition coil. Loosen wires from spark plugs by twisting spark plug boot carefully to loosen seal on spark plug. Remove wires by pulling on plug boot. Remove distributor cap from distributor, leaving wires connected to cap. NOTE: DO NOT disconnect wires from distributor cap unless replacement is necessary.
2. Using an ohmmeter, check resistance of each wire by connecting one ohmmeter lead to coil or spark plug terminal and other lead to distributor cap insert. If more than 5000 ohms resistance per INCH, remove wire and test again. If still over 5000 ohms per INCH, replace wire. New wires should have resistance of 7000 ohms per FOOT.

Note. Whenever high tension wire is disconnected, interior of spark plug terminal boot must be coated with silicone grease before reconnection.

HIGH TENSION WIRE RESISTANCE (OHMS)

ENGINE COMPRESSION

Test compression pressure with engine at normal operating temperature, all spark plugs removed, and throttle wide open. Crank engine through at least 5 compression strokes before recording pressure.

COMPRESSION SPECIFICATIONS

VALVE ARRANGEMENT

E-I-E-I-E-I-E-I (Front-to-rear).

VALVE CLEARANCE

All engines have hydraulic lifters. Lifters should be adjusted to zero lash.

DISTRIBUTOR

All 2.0L models are equipped with Dura-Spark II ignition system. All 2.3L EFI models are equipped with TFI-IV ignition system. No adjustments are required.

2.0L & 2.3L Timing Marks & Firing Order. Scheme 1

IGNITION TIMING

Note. Timing instrument should be connected to number one spark plug wire using an adapter or snap-on connector. Do not puncture spark plug wire or boot to make connection.

2.0L

1. Place transmission in Neutral. Turn A/C and heater off. Disconnect and plug vacuum lines at distributor. Connect inductive-type timing light and tachometer to engine.
2. Warm engine to normal operating temperature. With engine running at specified RPM, adjust ignition timing. Remove test equipment and reconnect all components.

2.3L

1. Warm engine to normal operating temperature and shut off engine. Turn all accessories off and place transmission in Neutral. Disconnect single wire (Black) connector near distributor.
2. Attach timing light. Start engine and check ignition timing. Adjust as needed.

IGNITION TIMING SPECIFICATIONS (DEGREES BTDC @ RPM)

HOT (SLOW) IDLE RPM

Curb Idle Checking - 2.0L 1-Bbl.

1. Place transmission in Neutral. Warm engine to normal operating temperature. Turn ignition off. Turn A/C, lights and accessories off. Leave all vacuum hoses connected.
2. Ensure curb idle RPM is at specification with transmission in Neutral. Turn ignition off. Disconnect engine coolant temperature switch. Switch has 2 wire (Light Green/Yellow and Black/Light Green) connector.
3. Restart engine. Idle speed should be 1125-1275 RPM. If not to specification, see the Electronic Idle Speed Control Article in the EXHAUST EMISSION SYSTEMS SECTION of this manual. Turn ignition off. Reconnect engine coolant temperature switch. Recheck idle RPM.

Carburetor Adjustment Screw Locations. Scheme 2

IDLE SPEED (RPM)

Minimum and Maximum Idle - 2.0L 1-Bbl.

1. Turn ignition switch off. Disconnect Idle Speed Control (ISC) motor connector. Disconnect EGR valve vacuum hose and plug. Connect insulated jumper wires from battery terminals to ISC motor terminals.
2. Motor should retract. If not, reverse jumper leads. Disconnect jumper leads when motor is fully retracted. If motor did not move in or out, replace ISC motor.
3. Start engine and adjust minimum idle speed (kill speed) to 700 RPM or less. Reverse jumper leads on ISC motor terminals. Disconnect terminals after ISC motor fully extends.
4. Check and adjust maximum idle speed to 1800-2200 RPM. Reconnect ISC motor connector. Remove plug from EGR vacuum hose and reconnect.

Extending & Retracting ISC Motor (Do Not Jumper ITS Terminals). Scheme 3

Note. For 2.3L EFI models this procedure is only performed if the curb idle is not 625-775 RPM (auto. trans.) or 575-725 RPM (man. trans.). Curb idle speed (RPM) is controlled by the EEC-IV processor and the idle speed control air by-pass valve assembly. If engine curb idle RPM is not within specification after performing this procedure, it will be necessary to perform the appropriate EEC-IV diagnostics.

Curb Idle - 2.3L EFI

1. Place transmission in Neutral (man. trans.) or "P" (auto. trans.). Turn A/C-Heat selector to the "OFF" position.
2. Bring engine to normal operating temperature then turn engine "OFF". Disconnect idle speed control air bypass valve power lead.
3. Start engine and operate at 1500 RPM for 20 seconds. Let engine idle and check base idle speed (600 RPM max.).
4. If RPM is too high, disconnect throttle cable. Back off throttle plate stop screw until there is clearance between screw and stop. Reconnect throttle cable and repeat step 3).
5. Shut engine off and reconnect power lead to idle speed control air by-pass valve. Verify throttle plate is not stuck in the bore by moving throttle plate. If excessive engine idle speeds are experienced when driving, turn ignition switch to "OFF" position and restart.

IDLE MIXTURE ADJUSTMENT

Note. Mixture adjustment is not a normal tune-up procedure. DO NOT remove idle mixture plugs unless vehicle fails emissions testing or carburetor has been disassembled.

Mixture Screw Plug Removal

1. Remove carburetor from engine. Drain fuel from carburetor. Using hacksaw, carefully cut lengthwise slot through metal cup around mixture screw. (Scheme 4)
2. Insert screwdriver into hacksaw slot and twist screwdriver to spread outer cap. Spread cap just enough to remove inner cap. Count number of turns required to seat mixture screw needle lightly. Remove mixture screw and cup.
3. When adjustment is completed, install idle mixture screw and spring. Install new tamper resistant cup. Turn screw in until it lightly seats. Turn screw out to same number of turns noted when disassembling. Reinstall carburetor on engine.

Making Hacksaw Cut In Mixture Screw Cup (Do Not Contact Carburetor Body With Hacksaw Blade). Scheme 4

Propane Enrichment Procedure

1. Apply parking brake and block drive wheels. Disconnect automatic brake release (if equipped) and plug vacuum connection. Connect tachometer to engine.
2. Disconnect fresh air duct from air cleaner. Insert propane supply hose 3/4 way into air cleaner duct, securing it with tape. Leave all vacuum hoses connected to air cleaner. Air cleaner may be positioned aside for adjustments, but must be in place during speed checks.
3. Disconnect and plug hose at air by-pass valve. Disconnect and plug hose between purge valve and spacer at purge valve. Verify timing and adjust if necessary. Turn A/C and all lights and accessories off. Remove PCV valve from its grommet. Disconnect crankcase hose at air cleaner.
4. Place transmission in Neutral and run engine approximately 2500 RPM for 15 seconds before each mixture check. If check is not completed within 1 minute, repeat 15-second acceleration.
5. With engine idling at normal operating temperature, place transmission in Neutral. Gradually open propane valve and watch for engine speed gain. When engine speed reaches maximum and begins to drop off, note amount of speed gain. NOTE: Propane bottle must be in vertical position. If engine speed will not drop off, check propane cartridge gas supply.
6. If measured speed gain is higher than specification, turn mixture screw counterclockwise (rich) slightly, then repeat steps 4) and 5) until gain matches "Reset RPM". NOTE: After turning idle mixture screw, wait 15 seconds for idle to stabilize before turning screw again.
7. If measured speed gain is lower than specification, turn mixture screw clockwise (lean) slightly, and repeat steps 4) and 5) until gain matches "Reset RPM".
8. Reconnect PCV valve and other disconnected components. Readjust curb idle speed if necessary. Remove test equipment.

PROPANE MIXTURE ADJUSTMENT (RPM)

COLD (FAST) IDLE RPM

1. Place transmission in Neutral. Start engine and warm to normal operating temperature. Stop engine and turn ignition and A/C off. Disconnect and plug vacuum hose at EGR valve.
2. Place fast idle speed adjusting screw on highest step of fast idle cam. Start engine without touching accelerator pedal. Check fast idle speed. Adjust to specification by turning fast idle speed adjusting screw. (Scheme 2)
3. Momentarily increase engine speed and let it return to idle. Turn ignition off. Reconnect vacuum hose at EGR and remove test equipment.

FAST IDLE SPEED (RPM)

AUTOMATIC CHOKE

Note. Although automatic choke is of tamper-proof design, these steps are used if automatic choke is damaged or when carburetor is rebuilt.

1. Choke housing is non-adjustable. Setting is fixed by an index plate located between carburetor and choke cover. Color of index plate indicates calibration setting.
2. To replace index plate, loosen choke thermostat cover. Remove 2 rivets and retaining screw. Separate cover from carburetor and exchange index plates. Replace cover. Install and tighten new rivets and screw.

FUEL PUMP

Make all tests with engine idling at normal operating temperature, and transmission in Neutral.

FUEL PUMP SPECIFICATIONS

FUEL SYSTEMS

CARBURETORS

Battery

BATTERY SPECIFICATIONS

Starter

All models use Motorcraft positive engagement type starter.

STARTER SPECIFICATIONS

Alternators

All models use Motorcraft rear-terminal alternators with external regulators.

ALTERNATOR SPECIFICATIONS

Alternator Regulator

All models use Motorcraft Solid State Electronic Regulator, calibrated and preset by manufacturer. No adjustment is required or possible. Two models are used. Though similar in appearance, they are different and must never be interchanged.

REGULATOR IDENTIFICATION

BELT ADJUSTMENT

BELT ADJUSTMENT TENSION IN LBS. (KG) USING STRAND TENSION GAUGE

All 2.0L models are equipped with Dura-Spark II ignition system. All 2.3L EFI models are equipped with TFI-IV ignition system. No adjustments are required.

DISTRIBUTOR PICK-UP COIL RESISTANCE

TOTAL SPARK ADVANCE @ 2500 RPM

Ignition Coil

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

SERVICE INTERVALS

REPLACEMENT INTERVALS

CAPACITIES

FLUID CAPACITIES

SYSTEM REFRIGERANT CAPACITY