Tune-Up - v8 Dodge Ram Van II

ENGINE IDENTIFICATION

Engine identification number is stamped on a pad located on right side of block, to the rear of engine mount. Engine can also be identified by 8th character in Vehicle Identification Number (VIN). VIN is located on a plate attached to upper left corner of instrument panel, near windshield.

Note. When ordering engine replacement parts, refer to engine serial number located on left front corner of block, below cylinder head.

ENGINE CODES

TUNE-UP NOTES

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

When performing tune-up on vehicles equipped with catalytic converter, do not allow or create a condition of engine misfire in more than one cylinder for an extended period of time. Total test time must not exceed 10 minutes or damage to converter may occur due to loading converter with unburned air/fuel mixture.

For tune-up purposes, "Light Duty" refers to vehicles 8500 lbs. GVW or less which must conform to light duty emission standards and "Heavy Duty" refers to vehicles over 8500 lbs. GVW which must conform to heavy duty emission standards.

Due to production changes, always refer to Emission Control Label in engine compartment before attempting tune-up. In the event of a conflict between specifications given in this manual and label specifications, use the label specifications.

When inspecting distributor rotor, a Black silicone varnish will be noticed covering .20-.30" (.50-.80 mm) of rotor electrode tip. This replaces earlier silicone grease used to suppress electromagnetic radiation. Grease will darken with age, has an ash-like appearance, and should not be removed. Ash formation (on both types of coverage) is normal and does not affect engine performance.

If it becomes necessary to replace the Spark Control Computer (SCC), do not disassemble computer for any reason. It is not serviceable and must be replaced as an assembly.

ENGINE COMPRESSION

Disconnect coil wire from distributor and secure to a good ground. Check compression pressure at cranking speed with engine warm, spark plugs removed and throttle valve wide open.

COMPRESSION SPECIFICATIONS

SPARK PLUGS

SPARK PLUG TYPE

SPARK PLUG SPECIFICATIONS

HIGH TENSION WIRE RESISTANCE

Note. Resistance type spark plug wires are identified by the words "Electronic Suppression" printed on cable jacket. Use an ohmmeter to check for open circuits, loose terminals and/or high resistance.

1. Carefully remove spark plug wire from spark plug by holding insulator (close to plug), rotating slightly and using a straight and steady pull. Lift distributor cap from distributor but do not remove wire from cap.
2. Connect an ohmmeter between spark plug end terminal and corresponding electrode inside cap. Check for proper resistance. If resistance is not within specifications, remove wire from distributor cap and test wire. See «HIGH TENSION WIRE RESISTANCE»(/dodge/ram-van/ii-1979-1993/remont/adjustments/#tune-up-v8) table.
3. Replace wire if not to specification. To check ignition coil wire resistance, remove distributor cap from distributor without removing wire from cap or coil. Connect an ohmmeter between center contact in cap and other end of wire. Check for proper resistance. See HIGH TENSION WIRE RESISTANCE table.
4. If resistance is not within specifications, remove wire at coil tower and repeat test. If resistance is still not within specifications, replace wire. Also check for loose connections at coil tower and/or faulty coil.

HIGH TENSION WIRE RESISTANCE (OHMS)

Vacuum Test

Disconnect inlet and outlet fuel lines from fuel pump. Connect vacuum gauge to fuel pump inlet fitting. Using starter motor, turn engine over several times and observe vacuum gauge. Fuel pump should develop a minimum of 11 in. Hg. of vacuum. If not, replace pump.

Pressure Test

Connect a pressure gauge to fuel pump outlet fitting. Using starter motor, turn engine over several times and observe pressure gauge. If pump does not develop specified pressure, replace pump.

FUEL PUMP SPECIFICATIONS

VALVE ARRANGEMENT

E-I-I-E-E-I-I-E (Front-to-rear, both banks).

VALVE CLEARANCE

All engines are equipped with hydraulic lifters. Lifters should be adjusted to zero lash.

DISTRIBUTOR

1. 5.2L 2-Bbl. Light Duty Emission Models are equipped with the Chrysler Electronic Spark Advance (ESA) system. All other models are equipped with the Chrysler Electronic Ignition (ECU) system. Unless a pick-up coil has been replaced, no adjustments are necessary.
2. 5.9L 4-Bbl. Light Duty Emission Models use a dual pick-up distributor. All other models use a single pick-up distributor.

PICK-UP COIL AIR GAP ADJUSTMENT

If pick-up coil air gap is not to specification, turn adjusting screw to set proper air gap. Using a non-magnetic feeler gauge, set air gap (start pick-up to reluctor) to .006" (.15 mm). After adjustment, ensure a .008" (.20 mm) feeler gauge will not pass through gap.

On dual pick-up coil distributor, set run pick-up coil to reluctor air gap to .012" (.30 mm). After adjustment, ensure a .014" (.36 mm) feeler gauge will not pass through gap.

Scheme 5

IGNITION TIMING

1. If a magnetic probe timing light is used, refer to equipment manufacturer's instruction for proper hookup. Use a 10° offset when required.
2. Turn off all lights and accessories. Disconnect and plug vacuum line at Spark Control Computer (if equipped), or at distributor. Connect a jumper wire between carburetor switch and ground (if equipped).
3. Connect tachometer to engine. Connect power timing light to No. 1 cylinder. Start engine and run in Neutral until normal operating temperature is reached. Ensure engine is running at or below curb idle RPM. If not, adjust curb idle. See «HOT (SLOW) IDLE RPM»(/dodge/ram-van/ii-1979-1993/remont/adjustments/#tune-up-v8) in this article.
4. Quickly open and release throttle to ensure linkage does not bind and that idle speed screw is against its stop. Aim power timing light at timing marks or read magnetic timing unit. CAUTION: DO NOT use distributor vacuum advance chamber as a turning handle when rotating distributor housing.
5. If timing is not within plus or minus 2° of specification, loosen distributor hold-down arm screw and rotate distributor housing to obtain correct timing. See IGNITION TIMING SPECIFICATIONS table. Tighten distributor hold-down screw when timing is correct.
6. Recheck idle speed and timing. If curb idle is not within plus or minus 50 RPM of specification, readjust idle and recheck timing.
7. Repeat procedure until both idle speed and timing are correct. Turn engine off, reconnect vacuum lines and remove jumper wire, tachometer and test equipment.

IGNITION TIMING SPECIFICATIONS (DEGREES BTDC @ RPM) (1)

ELECTRONIC SPARK ADVANCE (ESA) CHECK

Note. Due to cold engine spark advance schedules (which change during engine warm-up), ensure all spark advance testing is done with a fully warmed engine and properly connected and operating temperature sensor.

5.2L 2-Bbl.

1. Set ignition basic timing. Place thin insulating material (such as a piece of paper) between curb idle adjusting screw and carburetor switch. Remove and plug vacuum line at vacuum transducer.
2. Connect auxiliary vacuum source to transducer and set vacuum at 16 in. Hg of vacuum. With engine warm, run engine at 2000 RPM for one minute (or accumulator clock up time), then check spark advance. See ELECTRONIC SPARK ADVANCE SPECIFICATIONS.
3. Advance specifications are in addition to basic advance. Replace computer if advance is incorrect.

Note. On certain systems with an accumulator, specified time must be reached with carburetor switch ungrounded before checking specified spark advance schedule.

ELECTRONIC SPARK ADVANCE SPECIFICATIONS (1) (DEGREES BTDC @ 2000 RPM) (2)

5.2L 2-Bbl. - Solenoid Idle Stop RPM & Curb Idle RPM

1. Turn off all lights and accessories. Place transmission in Neutral or Park and set parking brake. Ensure that ignition timing is properly adjusted. Start and run engine until normal operating temperature is reached.
2. Remove air cleaner. Disconnect and plug 3/16" diameter control hose at canister and EGR hose at EGR valve. Remove PCV valve from rocker cover and allow valve to draw outside air. Install tachometer.
3. On A/C equipped models, energize the solenoid by turning A/C on with blower speed set to "LOW", and disconnecting the A/C compressor clutch wire. On non-A/C equipped models, energize the solenoid by installing a jumper wire between solenoid wire and positive battery post.
4. Slightly open throttle to allow solenoid plunger to extend. Remove the adjusting screw and spring from solenoid. Using a 1/8" Allen wrench, adjust to specified SIS RPM. (Scheme 6)
5. Reinstall solenoid screw and spring until it slightly bottoms out. De-energize solenoid. Disconnect and plug vacuum hose at computer. Disconnect wire from oxygen sensor (if equipped), and ground with a jumper wire. Let engine run for 4 minutes before preceding.
6. Turn screw on solenoid and adjust RPM to specification. (Scheme 6) Remove jumper wire and reconnect oxygen sensor. Reinstall PCV and EGR valves. Reconnect computer and canister vacuum hoses. Remove jumper wire from carburetor switch. Remove tachometer and shut engine off.

5.2L 2-Bbl. Solenoid Idle Stop RPM & Curb Idle RPM Adjustments (Holley Model 6280 Shown; Holley Model 2280 With 2-Position Solenoid Is Similar - Shown With Adjusting Screw & Spring In Place). Scheme 6

Note. Idle speed may vary under normal operating conditions (with all wires and hoses connected). This is normal and no readjustment is necessary.

SOLENOID IDLE STOP RPM & CURB IDLE RPM

5.2L 2-Bbl. - Curb Idle Speed RPM

1. Turn off all lights and accessories. Place transmission in Neutral or Park and set parking brake. Ensure that ignition timing is properly adjusted. Remove air cleaner. Disconnect and plug vacuum hose from heated air temperature sensor on carburetor.
2. Remove air cleaner. Disconnect and plug 3/16" diameter control hose at canister and EGR hose at EGR valve. Remove PCV valve from rocker cover and allow to draw fresh air. Disconnect and plug vacuum hose at distributor.
3. Ground carburetor switch with jumper wire. Install tachometer. Start and run engine for at least 2 minutes until normal operating temperature is reached.
4. If idle RPM is not correct, turn idle speed screw until specified RPM is obtained. (Scheme 7) Shut off engine, unplug and reconnect all vacuum hoses. Remove jumper wire and reconnect carburetor switch. Reinstall air cleaner and PCV valve. Remove tachometer.

CURB IDLE SPEED (RPM)

5.2L 2-Bbl. Curb Idle RPM Adjustment (Holley Model 2280 Without 2-Position Solenoid). Scheme 7

5.9L 4-Bbl. - Solenoid Idle Stop RPM

1. Turn off all lights and accessories. Check and adjust ignition timing. Remove air cleaner. Disconnect and plug vacuum hose at EGR valve and 3/16" diameter hose at canister. Remove PCV valve from valve cover and allow valve to draw underhood air.
2. Disconnect and plug vacuum hose at distributor. Install tachometer. Start engine and run for at least 2 minutes until normal operating temperature is reached.
3. On A/C equipped models, energize the solenoid by turning A/C on with blower speed set to "LOW", and disconnecting the A/C compressor clutch wire. On non-A/C equipped models, energize the solenoid by installing a jumper wire between solenoid wire and positive battery post.
4. Open throttle slightly to allow solenoid plunger to extend. Turn solenoid plunger and adjust to specified SIS RPM. (Scheme 8) Unplug and reconnect hoses. Reinstall PCV valve and air cleaner. Shut off engine and remove tachometer.

Note. Idle speed may vary under normal operating conditions (with all wires and hoses connected). This is normal and no readjustment is necessary.

SOLENOID IDLE STOP RPM

Rochester Quadrajet Carburetor Adjustments. Scheme 8

CURB IDLE SPEED RPM

1. Turn off all lights and accessories. Ensure timing is correct. Disconnect and plug vacuum hose at EGR valve. Disconnect and plug 3/16" diameter hose at canister (if equipped). Remove PCV valve from valve cover and allow it to draw fresh air. Disconnect and plug vacuum hose at distributor.
2. Connect tachometer to engine. Start engine and let speed stabilize for 2 minutes. If idle is not within specification, turn screw on carburetor that touches the throttle lever to adjust idle RPM. On Light Duty man. trans. models, turn solenoid plunger. (Scheme 8)
3. Unplug and reconnect vacuum hoses and reinstall PCV valve. Shut off engine and remove tachometer. Idle speed may vary under normal operating conditions (with all wires and hoses connected). This is normal and no readjustment is necessary.

CURB IDLE SPEED (RPM)

IDLE MIXTURE

Note. Idle mixture adjustment is not part of a normal tune-up. DO NOT adjust mixture unless carburetor has been disassembled or vehicle fails emissions testing.

Holley 2-Bbl. Carburetor Models 2280 & 6280

1. Remove air cleaner. Disconnect and mark (for reassembly reference) all hoses from front of carburetor. Center punch at a point about 1/4" from end of mixture screw housing. (Scheme 9)
2. Drill through outer section of housing, at punch mark, with 3/16" drill bit. Repeat operation on opposite side. Pry plugs out of housing and save for reassembly. Reinstall hoses and air cleaner.

2-Bbl. Carburetor Mixture Screw Plug Removal. Scheme 9

Rochester Quadrajet 4-Bbl. Carburetor

1. Remove carburetor, then turn over and drain out fuel. Place in holding fixture with manifold side up. Using a hacksaw, make 2 parallel cuts in throttle body, one on each side of locator point, beneath concealment plugs. (Scheme 10) NOTE: Cuts should reach down to plug, but must not extend more than 1/8" beyond locator points.
2. Place a small flat punch at a point near ends of saw marks. Hold punch at a 45° angle and drive into throttle body until casting breaks away. Plug should be exposed. Repeat procedure for other plug. Reinstall carburetor.

4-Bbl. Carburetor Mixture Screw Plug Removal (Carburetor Must Be Removed From Vehicle For Access To Mixture Screw Concealment Plugs). Scheme 10

Propane Enrichment Procedure - All Models

1. Turn off all lights and accessories, set parking brake and place transmission in Neutral or Park. Ensure timing is set to specification. Remove concealment plugs. Start and run engine until normal operating temperature is reached.
2. Ground carburetor switch (if equipped) with a jumper wire. Disconnect and plug vacuum hoses at distributor or computer (if equipped), EGR valve and 3/16" diameter canister. Remove PCV valve from valve cover and allow to draw outside air.
3. On vehicles equipped with oxygen sensors, disconnect wire from oxygen sensor and ground with a jumper wire. Let engine run for 4 minutes to allow disconnect to take place.
4. Connect tachometer to engine. Disconnect vacuum supply hose from choke vacuum kick diaphragm at carburetor and install the propane supply hose in its place. Open propane main valve then slowly open propane metering valve until maximum engine speed is reached. NOTE: When too much propane is added, engine speed will decrease. Fine tune metering valve for highest possible RPM. Also, if idle mixture is too rich, engine RPM will decrease with propane. In such cases, turn idle mixture screw in approximately 1/2 turn and repeat propane valve opening procedure.
5. With propane flowing, adjust idle speed screw until specified propane RPM is reached. (Scheme 6), (Scheme 7) and (Scheme 8). Fine tune metering valve for highest possible RPM. If maximum RPM changes, readjust idle speed screw to specified propane RPM.
6. Turn off main propane valve and allow engine speed to stabilize. Slowly adjust mixture screws until specified curb idle is reached. Let engine stabilize then turn on main propane valve.
7. Fine tune to maximum RPM. If engine speed varies 25 RPM or more from propane specification, repeat steps 4) through 7). Turn off both valves on propane bottle.
8. Reconnect oxygen sensor (if equipped). Reinstall PCV into cover. Reconnect all vacuum hoses and remove jumper wire from carburetor switch (if equipped). Shut engine off and remove tachometer. Reinstall concealment plugs.

Note. If the idle speed varies under normal operating conditions (with all wires and hoses connected). This is normal and no readjustment is necessary.

PROPANE MIXTURE ADJUSTMENT (RPM)

All Models

1. Turn off all lights and accessories, set parking brake and place transmission in Neutral or Park. Ensure timing is set to specification. Remove concealment plugs. Start and run engine until normal operating temperature is reached.
2. Ground carburetor switch (if equipped) with a jumper wire. Disconnect and plug vacuum hoses at distributor or computer (if equipped), EGR valve and 3/16" diameter canister. Remove PCV valve from valve cover and allow to draw outside air.
3. On vehicles equipped with oxygen sensors, disconnect wire from oxygen sensor and ground with a jumper wire. Let engine run for 4 minutes to allow disconnect to take place.
4. Connect tachometer to engine. Open throttle and place fast idle speed screw on second highest step of fast idle cam. Turn fast idle speed screw until specified RPM is reached. (Scheme 6), (Scheme 7) and (Scheme 8).
5. Return engine to curb idle. Let engine stabilize then reset adjusting screw on second highest step of fast idle cam to verify fast idle speed. Readjust if necessary.
6. Return engine to idle RPM. Reconnect oxygen sensor (if equipped). Reinstall PCV into cover. Reconnect all vacuum hoses and remove jumper wire from carburetor switch (if equipped). Shut engine off and remove tachometer.

Note. Idle speed may vary under normal operating conditions (with all wires and hoses connected). This is normal and no readjustment is necessary.

FAST IDLE SPEED (RPM)

AUTOMATIC CHOKE

All models are equipped with non-adjustable choke covers. However, choke linkage and shaft must move freely hot or cold. Choke rods must be examined carefully for damage or bending. Use caution when installing carburetor to prevent damage to choke rod. Do not force rod if it becomes trapped, release it by removal only.

CHOKE VALVE SHAFT

1. To prevent choke from sticking due to gum deposits on shaft, spray Mopar Combustion Chamber Conditioner (4318001) onto choke shaft where it passes through air horn. NOTE: Service choke valve shaft, fast idle cam and pivot pin every 12,000 miles for heavy duty models and every 30,000 miles on light duty models or every 12 months, whichever comes first.
2. Move choke blade back and forth to distribute solvent. Apply solvent to fast idle cam and pivot pin to remove dirt, oil and other deposits that may have collected which could cause sticking or erratic motion.

5.2L 2-Bbl. Light Duty Emission Models are equipped with the Chrysler Electronic Spark Advance (ESA) system. All other models are equipped with the Chrysler Electronic Ignition (ECU) system. Unless a pick-up coil has been replaced, no adjustments are necessary.

5.9L 4-Bbl. Light Duty Emission Models use a dual pick-up distributor. All other models use a single pick-up distributor.

DISTRIBUTOR PICK-UP COIL RESISTANCE

DISTRIBUTOR PICK-UP COIL AIR GAP (1)

IGNITION COIL & BALLAST RESISTOR

IGNITION COIL RESISTANCE (OHMS) (1)

BALLAST RESISTOR RESISTANCE (1)

ALTERNATOR REGULATOR

All models use Chrysler Corp. Electronic Voltage Regulator. Unit is nonadjustable. Ensure battery specific gravity is above 1.200 when checking regulated voltage.

REGULATOR OPERATING VOLTAGE @ 80°F (27°C)

EMISSION CONTROL

For information on emission control systems, see appropriate article in the EMISSION section.

FUEL SYSTEMS

CARBURETORS

BATTERY

BATTERY SPECIFICATIONS

STARTER

All models use Chrysler Corp. reduction gear type starter.

STARTER TEST SPECIFICATIONS (1)

ALTERNATOR

ALTERNATOR SPECIFICATIONS

DRIVE BELT ADJUSTMENTS

DRIVE BELT ADJUSTMENT

SERVICE INTERVALS

REPLACEMENT INTERVALS

CAPACITIES

COOLING SYSTEM CAPACITIES

ENGINE OIL & FUEL CAPACITIES

TRANSMISSION, TRANSFER CASE & DIFFERENTIAL CAPACITIES

A/C SYSTEM REFRIGERANT CAPACITIES

See also:
• HIGH TENSION WIRE RESISTANCE