Engine Controls - Basic Testing: Other Dodge Intrepid I

Compression

Check engine mechanical condition with a compression gauge, vacuum gauge or engine analyzer. See engine analyzer manual for specific instructions.

ENGINE COMPRESSION SPECIFICATIONS (1)

Exhaust System Backpressure

The exhaust system can be checked with a vacuum gauge or pressure gauge. If using a pressure gauge, remove O2 sensor or air injection check valve (if equipped). Connect a 0-10 psi gauge, and operate 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 it steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restriction.

FUEL SYSTEM

FUEL PRESSURE

Basic diagnosis of fuel system should begin with determining fuel system pressure.

Note. Relieve fuel pressure at fuel rail test port (if equipped). See RELIEVING FUEL PRESSURE (VEHICLES WITH FUEL RAIL TEST PORTS). If vehicle is not equipped with a fuel rail test port, see appropriate fuel pressure release procedure.

Relieving Fuel Pressure (Except 2.2L & 2.5L TBI)

Slowly open fuel tank cap to release pressure in tank. To release remaining pressure in system, disconnect injector wiring harness connector at edge of first injector. Using jumper wire, apply battery voltage to Dark Green/Orange wire at connector terminal. Using a second jumper wire, momentarily ground the other connector terminal. Repeat procedure for other injectors. Connect injector wiring harness connector. Fuel pressure is now released.

Relieving Fuel Pressure (2.2L & 2.5L TBI)

Slowly open fuel tank cap to release pressure in tank. Disconnect injector harness connector at edge of throttle body. Using jumper wire, ground injector harness connector terminal No. 1. (Scheme 52) Using a second jumper wire, apply battery voltage to injector harness connector terminal No. 2. DO NOT apply battery voltage to terminal No. 2 for more than 5 seconds. Remove jumper wires. Connect injector wiring harness connector. Fuel pressure is now released.

Scheme 52

2.2L, 2.5L TBI & 3.0L

1. Relieve fuel pressure. See appropriate RELIEVING FUEL PRESSURE procedure under FUEL PRESSURE. On 3.0L, disconnect vacuum hose from fuel pressure regulator before checking fuel pressure.
2. On 2.2L and 2.5L TBI, fuel pressure regulator is not vacuum assisted. On all engines, disconnect fuel supply hose quick-disconnect connector from chassis lines at engine. Connect Fuel Pressure Gauge (C-4799) to Fuel Pressure Test Adapter (6539). Install adapter between fuel supply hose and chassis fuel line. CAUTION: DO NOT activate fuel pump for long periods, or engine may hydrostatically (liquid) lock.
3. Using Diagnostic Readout Box (DRB), turn ignition switch to ON position. Select ASD FUEL SYSTEM TEST mode. In this mode, DRB energizes Auto Shutdown (ASD) relay, causing fuel pump to activate and pressurizing fuel system.
4. Note fuel pressure, and record reading. Relieve fuel pressure. Remove fuel pressure gauge. If fuel pressure is within specification, fuel system is functioning properly and further testing is not required. See FUEL SYSTEM PRESSURE SPECIFICATIONS table.
5. If fuel pressure is greater than specification, go to step 8). If fuel pressure is less than specification, install Fuel Pressure Gauge(C-4799) and Fuel Pressure Test Adapter (6539) in fuel supply line between fuel tank and fuel filter.
6. Repeat ASD FUEL SYSTEM TEST. If fuel pressure is at least 5 psi greater than fuel pressure recorded in step 4), replace fuel filter. If no change is observed, gently squeeze fuel return hose.
7. If fuel pressure increases while squeezing fuel return hose, replace fuel pressure regulator. If fuel pressure does not change while squeezing fuel return hose, problem may either be a plugged fuel inlet strainer or defective fuel pump. Repair as necessary.
8. Disconnect fuel return hose from fuel pump at fuel tank. Connect Fuel Pressure Test Adapter (6541) to fuel return hose. Place other end of adapter into an approved 2 gallon gasoline container.
9. Turn ignition switch to ON position. Repeat ASD FUEL SYSTEM TEST. If pressure is now correct, replace fuel pump assembly. See FUEL SYSTEM PRESSURE SPECIFICATIONS table. If pressure is still greater than specification, deactivate fuel pump. Remove fuel pressure test adapter, and connect fuel pump return hose.
10. Disconnect fuel return hose from chassis fuel lines at engine. Connect Fuel Pressure Test Connector Adapter (6541) to fuel return hose. Place other end of hose in an approved gasoline container. Repeat ASD FUEL SYSTEM TEST.
11. If pressure is now correct, check for restricted fuel return line. If no change is observed, replace fuel pressure regulator.

FUEL SYSTEM PRESSURE SPECIFICATIONS

2.5L Flexible Fuel, 3.3L & 3.5L

1. Relieve fuel pressure. See appropriate RELIEVING FUEL PRESSURE procedure under FUEL PRESSURE. Disconnect vacuum hose from fuel pressure regulator before checking fuel pressure. Remove fuel rail test port protective cap. Connect Fuel Pressure Gauge (C-4799) to fuel rail test port (if equipped). CAUTION: DO NOT activate fuel pump for long periods, or engine may hydrostatically (liquid) lock.
2. Using Diagnostic Readout Box (DRB), turn ignition switch to ON position. Select ASD FUEL SYSTEM TEST mode. In this mode, DRB energizes Auto Shutdown (ASD) relay, causing fuel pump to activate and pressurizing fuel system.
3. Note fuel pressure, and record reading. Deactivate fuel pump. Relieve fuel pressure. Remove fuel pressure gauge. Reactivate fuel pump. Ensure fuel does not leak from fuel rail test port (if equipped). Deactivate fuel pump. Install fuel rail test port protective cap.
4. If fuel pressure is within specification, fuel system is functioning properly and further testing is not required. See FUEL SYSTEM PRESSURE SPECIFICATIONS table. If fuel pressure is greater than specification, go to step 7). If fuel pressure is less than specification, install Fuel Pressure Gauge (C-4799) and Fuel Pressure Test Adapter (6539) in fuel supply line between fuel tank and fuel filter.
5. Using DRB, repeat ASD FUEL SYSTEM TEST. If fuel pressure is at least 5 psi greater than fuel pressure recorded in step 3), replace fuel filter. If no change in fuel pressure is observed, gently squeeze fuel return hose.
6. 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.
7. Remove fuel return hose from fuel pump at fuel tank. Connect Fuel Pressure Test Adapter (6541) to return hose. Place other end of adapter into an approved gasoline container (minimum 2 gallon size).
8. Turn ignition switch to ON position. Repeat ASD FUEL SYSTEM TEST. If fuel pressure is now correct, replace fuel pump assembly. See FUEL SYSTEM PRESSURE SPECIFICATIONS table. If pressure is still greater than specification, deactivate fuel pump. Remove fuel pressure test adapter, and connect fuel pump return hose.
9. Disconnect fuel return hose from chassis fuel lines at engine. Connect Fuel Pressure Test Connector Adapter (6541) to fuel return hose. Place other end of hose in approved gasoline container. Repeat ASD FUEL SYSTEM TEST.
10. If fuel pressure is now correct, check for restricted fuel return line. If no change is observed, replace fuel pressure regulator.

IGNITION CHECKS

IGNITION SYSTEM IDENTIFICATION

Ignition Coil Resistance

Ignition coil resistance test procedure is not available from manufacturer. Use IGNITION COIL RESISTANCE table under IGNITION COIL to determine correct coil resistance.

Scheme 53

Scheme 54

Scheme 55

1. Remove ignition coil secondary cable from distributor cap. Hold end of cable 1/4" away from a known-good engine ground. Crank engine and check for spark.
2. If spark is not constant or if there is no spark, go to step 4). If spark is constant, slowly move coil secondary cable away from ground while assistant cranks engine. If arcing occurs at coil tower, replace ignition coil.
3. If spark is constant and no arcing occurs, ignition system secondary voltage is correct. Ensure secondary voltage reaches spark plugs, indicating ignition system is okay. Go to MECHANICAL INSPECTION under PRELIMINARY INSPECTION & ADJUSTMENTS. Perform tests under FUEL SYSTEM.
4. Ensure battery is fully charged (at least 12.4 volts). Connect volt-meter to ignition coil B+ (battery) terminal. (Scheme 53)and (Scheme 54). Crank engine for at least 5 seconds while checking voltage at coil terminal.
5. If voltage remains near zero during entire cranking period, test Auto Shutdown (ASD) relay circuit. See appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section listed below.
6. If voltmeter reading is near battery voltage and then drops to zero after 1-2 seconds of cranking, test distributor reference pick-up circuit. See appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section listed below.
7. If voltmeter reading remains at or near battery voltage during entire cranking period, turn ignition off. Disconnect 60-pin connector from Powertrain Control Module (PCM), and check terminals for poor connections. (Scheme 55) «TESTS W/CODES - 2.2L»(ref-10830) «TESTS W/CODES - 2.5L TBI»(ref-10831) «TESTS W/CODES - 2.5L FLEX FUEL»(ref-10825) «TESTS W/CODES - 3.0L»(ref-10826) «TESTS W/CODES - 3.3L»(ref-10827) «TESTS W/CODES - 3.5L»(ref-10832)
8. Remove positive lead from coil. Connect a jumper wire between battery positive terminal and coil positive terminal. Using a specially constructed jumper wire, momentarily ground PCM harness connector terminal No. 19. (Scheme 55)and (Scheme 56). Spark should occur when ground connection is disconnected.
9. If spark occurs, replace PCM. If spark does not occur, ground coil negative terminal using specially constructed jumper wire. (Scheme 56) If spark occurs, repair open circuit in wiring harness. If spark does not occur, replace ignition coil.

Ignition coil resistance test procedure is not available from manufacturer. Use IGNITION COIL RESISTANCE table under IGNITION COIL to determine correct coil resistance.

Scheme 56

IGNITION COIL

IGNITION COIL RESISTANCE

IDLE SPEED & IGNITION TIMING

Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ADJUSTMENTS article in the ENGINE PERFORMANCE section.

SUMMARY

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

1. «TESTS W/CODES - 2.2L»(ref-10830)
2. «TESTS W/CODES - 2.5L TBI»(ref-10831)
3. «TESTS W/CODES - 2.5L FLEX FUEL»(ref-10825)
4. «TESTS W/CODES - 3.0L»(ref-10826)
5. «TESTS W/CODES - 3.3L»(ref-10827)
6. «TESTS W/CODES - 3.5L»(ref-10832)