Engine Controls - Basic Diagnostic Procedures - Gasoline: Other Dodge Pickup R1500

Testing & Diagnostics 7 illustrations ~721 words

Cylinder Compression Pressure

Ensure battery is fully charged and starter motor is in good operating condition. Clean spark plug recesses with compressed air. Remove all spark plugs. On Ram Pickup, remove fuel pump relay from Power Distribution Center (PDC). (Scheme 1006) PDC is located in right side of engine compartment, next to battery. On Ram Van, remove fuel pump relay from fuse block. (Scheme 1007) Fuse block is located in left end of instrument panel. (Scheme 1012) On all models, install compression gauge. Hold throttle in wide open throttle position. Using a remote starter switch, rotate engine 3 revolutions. Record compression pressure from third revolution. Continue test for remaining cylinders. See COMPRESSION SPECIFICATIONS table for correct engine compression pressures.

Application	Psi (kg/cm 2 )
Normal Compression Pressure	(1)
Minimum Compression Pressure	100 (7.0)
Maximum Variation Between Cylinders	(1)
(1) Information is not available from manufacturer.

(1)	Information is not available from manufacturer.

COMPRESSION SPECIFICATIONS

Scheme 1006

Scheme 1007

Scheme 1008

Scheme 1009

Vacuum

Note. Vacuum readings can vary according to altitude.

Turn ignition off. Install vacuum "T" fitting and vacuum gauge at vacuum source on intake manifold. Start engine and allow it to idle. While monitoring vacuum gauge reading, quickly open (snap) throttle to full open and back to closed position several times. Vacuum gauge reading should change from about 13-22 in. Hg. If vacuum reading is within specification, test is complete. If vacuum reading is not within specification, check for engine mechanical condition. See appropriate article in ENGINES.

CHECKING HARD START (FUEL DELIVERY SYSTEM)

For testing procedures (Scheme 1010)and (Scheme 1011).

Scheme 1010

Scheme 1010: CHECKING HARD START (FUEL DELIVERY SYSTEM)

Scheme 1011

ENGINE CRANKS BUT DOES NOT START

Note. For circuit identification and wiring diagrams, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-5 under VERIFICATION TESTS to ensure system is functioning properly.

NO RESPONSE FROM PCM WITH A NO-START CONDITION

Note. For circuit identification and wiring diagrams, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS to ensure system is functioning properly.

FUEL SYSTEM PRESSURE RELEASE

WARNING

Fuel system is under high pressure. ALWAYS release fuel pressure before attempting to open system for testing or component replacement. DO NOT allow fuel to flow onto engine or electrical parts while testing fuel system components.

On Ram Pickup, remove fuel pump relay from Power Distribution Center (PDC). (Scheme 1006) PDC is located in right side of engine compartment, next to battery. On Ram Van, remove fuel pump relay from fuse block. (Scheme 1007) Fuse block is located in left end of instrument panel. (Scheme 1012) On all models, start and run engine until it stalls. Attempt to start engine. Continue restarting engine until it will no longer run. Turn ignition off.
Disconnect any fuel injector connector. Connect a jumper wire between either fuel injector terminal and positive battery terminal. Connect another jumper wire to other fuel injector terminal. Momentarily touch other end of jumper wire to negative battery terminal.
Place a shop towel under fuel line quick-connector at fuel rail. Use care when disconnecting fuel lines, as some fuel pressure may still exist in fuel lines. Disconnect fuel line quick-connector at fuel rail. Reinstall fuel pump relay in PDC. Reconnect fuel line quick-connector. Using scan tool, erase any DTCs that may have set after fuel pressure release procedure.

Scheme 1012

Fuel Pump Relay

For fuel pump relay and circuit testing, see DTC P1282: FUEL PUMP RELAY CONTROL CIRCUIT under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

CAMSHAFT POSITION SENSOR

For Camshaft Position (CMP) sensor circuit testing, see DTC P0340: NO CAM SIGNAL AT PCM under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

CRANKSHAFT POSITION SENSOR

For Crankshaft Position (CKP) sensor circuit testing, see DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

IGNITION COIL

Ignition coil resistance is measured at 70-80°F (21-27°C). See IGNITION COIL RESISTANCE table.

Application	Primary	Secondary
3.7L & 4.7L	.6-.9	6000-9000
3.9L, 5.2L & 5.9L
Diamond Coil	.97-1.18	11,300-15,300
Toyodenso Coil	.95-1.20	11,300-13,300
8.0L	.53-.65	10,900-14,700

IGNITION COIL RESISTANCE

SPARK PLUG WIRES

Measurement	Ohms - Per Inch	Ohms - Per Foot
Minimum	250	3000
Maximum	1000	12,000

SPARK PLUG WIRE RESISTANCE

IDLE SPEED & IGNITION TIMING

Idle speed and mixture are controlled by Powertrain Control Module (PCM). No adjustment is necessary. Ignition timing is not adjustable on any engine. All ignition timing functions are controlled by the PCM.