Basic Testing Saab 9000 I

INTRODUCTION

The following diagnostic steps are here to prevent overlooking a simple problem. This is also the place to start diagnosis for a "NO-START" condition.

The first step in diagnosing any driveability problem is to verify that the problem exists. This may be accomplished by test driving the vehicle under the conditions during which the problem reportedly occurs.

Prior to entering self-diagnostics, a careful and complete inspection of several systems is required. Most driveability or "no-start" problems are not related to computerized engine control systems, but are in fact simple mechanical, electrical, fuel or vacuum related faults. Most engine control problems are the result of mechanical breakdowns, poor electrical connections or damaged or misrouted vacuum hoses.

Before considering the computer system as a possible cause of problems, ignition high tension wires, fuel supply, electrical connections and vacuum hoses should be checked. Failure to do so may result in improper diagnosis or lost diagnostic time.

Note. All voltage tests should be performed with a Digital Volt Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated different in testing procedures.

VISUAL INSPECTION

Perform a visual inspection of all electrical wiring. Look for chafed, stretched, cut or pinched wiring. Inspect electrical connectors and connections for tight fit and corrosion. Repair as necessary. Inspect all vacuum hoses for proper routing, cuts or pinches. If necessary, see VACUUM DIAGRAMS article to verify routing and connections. Repair as necessary. Inspect air induction system for possible vacuum leaks.

Compression

Engine mechanical condition can be checked using a compression gauge, vacuum gauge, or an engine analyzer capable of performing a relative compression test. See engine analyzer instruction manual for availability and description of relative compression feature.

Exhaust System Backpressure

The exhaust system can be checked with a vacuum gauge or a pressure gauge. Remove O2 sensor or air injection check valve, if equipped. Connect a 1-10 psi gauge and run 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. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge slowly drops after stabilizing, exhaust system should be checked for a restriction.

FUEL PRESSURE

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

Fuel Line Pressure

1. Disconnect banjo coupling at inlet to fuel injection manifold. Connect a fuel pressure gauge using existing seals. Ensure pressure gauge hangs vertically.
2. Turn ignition off. Remove fuse No. 30 on 900 models. Remove fuse No. 14 and No. 22 from 9000 models. Connect a jumper lead between fuse No. 27, 28, or 29 and slot of fuse No. 30 for 900 models. Connect the jumper between fuse No. 22 and slot of fuse No. 14 on 9000 models. This will provide current to the fuel pump. Turn ignition on.
3. Line pressure should rise to approximately 35 psi (2.5 kg/cm 2 ). If line pressure is too high, go to next step. If line pressure is too low, go to step 5).
4. Turn ignition off. Disconnect fuel return line from pressure regulator and blow through line. If line is open, pressure regulator is defective and should be replaced. If line is blocked, unblock, or replace with a new return line. Check one-way valve at tank, and retest system.
5. Check fuel level, do not rely on fuel gauge. Check for fuel system leaks. Check fuel pressure regulator. Refer to the «FUEL PRESSURE REGULATOR»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#basic-testing__fuel-pressure-regulator) test. If proceeding to FUEL PRESSURE REGULATOR test, do not remove fuel pressure gauge.

Fuel Pressure Regulator

1. If fuel pressure gauge is already attached, go to next step. If not, disconnect banjo coupling at inlet to fuel injection manifold. Connect fuel pressure gauge at this point, using existing seals. Ensure pressure gauge hangs vertically.
2. Connect Pressure Gauge (83 93 514 ), with "Y" connection, to vacuum port of fuel pressure regulator. Hang pressure gauge vertically. Connect cooling system pressure tester to "Y" connection.
3. Turn ignition off. Remove fuse No. 30 on 900 models. Remove fuse No. 14 and No. 22 from 9000 models. Connect a jumper lead between fuse No. 27, 28, or 29 and slot of fuse No. 30 for 900 models. Connect the jumper between fuse No. 22 and slot of fuse No. 14 on 9000 models. This will provide current to the fuel pump. Turn ignition on.
4. Line pressure should rise to approximately 35 psi (2.5 kg/cm 2 ). Using a pressure tester, raise system pressure to various test pressures, and compare line pressure to specification. Refer to the «APPLIED PRESSURE REGULATOR SPECIFICATIONS»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#basic-testing) table. APPLIED PRESSURE REGULATOR SPECIFICATIONS Applied Pressure: psi (kg/cm 2 ) Line Pressure: psi (kg/cm 2 ) 0 (0) 35.0 (2.5) 2.8 (.2) 37.8 (2.7) 5.6 (.4) 40.6 (2.9) 8.4 (.6) 43.4 (3.1)
5. Remove pressure tester. Install vacuum pump to "Y" connection. Line pressure should be at approximately 35 psi (2.5 kg/cm 2 ). Use vacuum pump to create various test vacuums, and compare vacuum readings to specification. See «APPLIED VACUUM REGULATOR SPECIFICATIONS»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#basic-testing) table. APPLIED VACUUM REGULATOR SPECIFICATIONS Applied Vacuum In. Hg Line Pressure: psi (kg/cm 2 ) 0 (0) 35.0 (2.5) 2.8 32.2 (2.3) 5.6 29.4 (2.1) 8.4 26.6 (1.9)
6. Turn ignition on to operate fuel pump. Verify fuel line pressure of 35 psi (2.5 kg/cm 2 ). Turn ignition off. Check pressure gauge reading. Pressure should drop 1.4-2.8 psi (.1-.2 kg/cm 2 ), and then hold steady for at least 10 minutes.
7. If pressure drops more than specified, check for leakage in pressure regulator and fuel pump non-return valve.

Fuel Pump Delivery Pressure

1. Turn ignition on. Pinch off fuel return line, and check line pressure. When line is plugged, there should be an immediate rise in line pressure. CAUTION: DO NOT allow pressure to rise above 83 psi (5.8 kg/cm 2 ).
2. If line pressure does not increase, check for the following problems: At least 11.5 volts across fuel pump terminals. Obstructed fuel lines. Clogged fuel filter. Fuel filter installed backward. Defective relief valve in fuel pump. NOTE: If fuel filter has been installed backwards, it must be replaced.
3. After checking fuel pump pressure, turn ignition off. Go to «FUEL PUMP DELIVERY FLOW»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#basic-testing__fuel-pump-delivery-flow) test procedure ( DO NOT disconnect pressure gauge).

Fuel Pump Delivery Flow

1. Turn ignition off. Disconnect fuel return line at pressure regulator. Connect a section of test hose to return line at pressure regulator. Place other end of test hose in graduated container of about 2 quarts.
2. Activate fuel pump by turning ignition on. Run fuel pump for 30 seconds. Check volume of fuel flow and fuel pressure drop. Minimum acceptable volume is .95 qts. (.9 L), and maximum allowed fuel pressure drop is 1.4-2.8 psi (.1-.2 kg/cm 2 ). If fuel volume or pressure drop does not meet specification, replace fuel pressure regulator.

Spark

Check for spark at coil wire (if applicable) and at each spark plug wire using a high output spark tester. Check spark plug wire resistance on suspect wires. Resistance should be 2000-4000 ohms. Coil wire resistance should be 500-1500 ohms.

Ignition Coil Power Source

Turn ignition on. Using voltmeter, check voltage between terminal ("B") and ground of each ignition coil plug. Battery voltage should exist.

Ignition Coil Resistance

1. Remove primary and secondary leads from ignition coil. Using ohmmeter, check primary resistance between (positive) and (negative) terminals of coil. Resistance should be as specified. See the «IGNITION COIL RESISTANCE»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#basic-testing) table.
2. Check secondary resistance between (positive) and (negative) terminals of coil. Resistance should be as specified. Replace coil if readings were not within specification. Refer to the «IGNITION COIL RESISTANCE»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#basic-testing) table. IGNITION COIL RESISTANCE - Ohms @ 68°F (20°C) Application Primary Secondary All Models .52-.76 7200-8200

Tach Pulse Signal

The engine speed signal is generated by an electronic (Hall Effect) ignition. The low voltage ignition primary pulses are monitored at low tension side of ignition coil. Injection timing is regulated by this signal.

The Hall Effect sensor is mounted at crankshaft pully. Sensor energizes ignition amplifier, closing primary circuit and charging ignition coil. Pulse from sensor is amplified and sent to ignition coil where it is used as tachometer (RPM) signal and monitored by the ECU. The ECU transmits signals to the ignition system which opens the primary circuit of the coil and triggers ignition spark.

Note. All voltage tests should be performed with a Digital Volt Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated different in testing procedures.

Hall Effect Sensor

Make all checks at the back of electrical connectors for EZK electronic control unit (ECU) with ignition on.

1. To test sensor supply voltage, connect voltmeter between terminal No. 10 and 4 of ECU. See the «WIRING DIAGRAMS»(/saab/9000/i-1984-1994/remont/wiring-diagrams-engine-performance/#wiring-diagrams-cec) article. Voltmeter reading should be battery voltage.
2. To test signal from Hall Effect sensor to ECU, connect voltmeter between terminal No. 10 and 24 of ECU. Refer to the «WIRING DIAGRAMS»(/saab/9000/i-1984-1994/remont/wiring-diagrams-engine-performance/#wiring-diagrams-cec) article. Slowly turn engine by hand Voltmeter reading should vary from 0.4 to 3.0 volts as Hall Effect sensor shutter opens and closes.

IDLE SPEED & IGNITION TIMING

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

IDLE SPEED SPECIFICATIONS

IGNITION TIMING (Degrees BTDC @ RPM) (1)

SUMMARY

If no faults were found while performing BASIC TESTING , proceed to G - TESTS W/ CODES article. If no hard codes are found in self-diagnostics, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.), or intermittent diagnosis procedures.

See also:
• WIRING DIAGRAMS
• ADJUSTMENTS
• G - TESTS W/ CODES
• TESTS W/O CODES
• FUEL PRESSURE REGULATOR
• APPLIED PRESSURE REGULATOR SPECIFICATIONS
• FUEL PUMP DELIVERY FLOW