Engine Controls - Basic Testing Ford Econoline E350

MODEL IDENTIFICATION

Note. Unless otherwise specified, references to Pickup include the F350 Super Duty commercial chassis.

MODEL IDENTIFICATION

INTRODUCTION

The following diagnostic steps will help prevent overlooking a simple problem. This is also where to begin diagnosis for a no-start condition.

The first step in diagnosing any driveability problem is verifying the customer's complaint with a test drive under the conditions the problem reportedly occurred.

Before entering self-diagnostics, perform a careful and complete visual inspection. Most engine control problems result from mechanical breakdowns, poor electrical connections or damaged/misrouted vacuum hoses. Before condemning the computerized system, perform each test listed in this article.

Note. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure.

VISUAL INSPECTION

Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not pinched or cut. See VACUUM DIAGRAMS article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.

Compression

Check engine mechanical condition using a compression gauge, vacuum gauge or engine analyzer. If using engine analyzer, see engine analyzer manual for specific instructions. Compression pressures are considered within specifications if lowest reading cylinder is within 75 percent of highest reading cylinder.

Exhaust System Backpressure

Using a vacuum or pressure gauge, check exhaust system. Remove O2 sensor or air injection check valve (if equipped). Connect a 0-5 psi pressure gauge, and run engine at 2500 RPM. If exhaust system backpressure is greater than 2 psi, exhaust system or catalytic converter is plugged.

If using a vacuum gauge, connect vacuum gauge hose to intake manifold vacuum port, and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restrictions.

NO-START DIAGNOSIS

Note. For diesel information, see TESTS W/O CODES article.

DEFINITION

No-start is defined as engine cranks okay, but does not start. Engine may fire a few times.

PRELIMINARY CHECKS

Before diagnosing problems in ignition system, ensure following systems and components are in good condition and operating properly.

1. Battery
2. State of tune
3. Fuel delivery and injection system
4. All wiring and vacuum connections
5. Air cleaner and ducts
6. Cooling system

Spark Output Check

1. Check EEC-IV system for fault codes and repair if necessary. See QUICK TEST in TESTS W/CODES article. If no fault codes are retrieved, check ignition system wiring harness connectors for corrosion and tight fit. (Scheme 18)
2. If wiring and connectors are okay, use Neon Bulb Spark Tester (D89P-6666-A) to check for spark at each spark plug wire while cranking engine. If spark is consistent and equal at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to IGNITION SYSTEMS in SYSTEM/COMPONENT TESTS article.

Scheme 18

1. Check EEC-IV system for fault codes and repair if necessary. See QUICK TEST in TESTS W/CODES article. If no fault codes are retrieved, check ignition system wiring harness connectors for corrosion and tight fit. Repair or replace as necessary.
2. If wiring and connectors are okay, use Neon Bulb Spark Tester (D89P-6666-A) to check for spark at each spark plug wire while cranking engine. If spark is consistent and equal at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to IGNITION SYSTEMS in SYSTEM/COMPONENT TESTS article.

Spark Check

1. Using a high output spark tester, check for spark at coil wire while cranking engine. If spark is present, go to step 2). If spark is not present, remove distributor cap, and crank engine to check for distributor rotation. If distributor rotation is okay, check coil secondary wire resistance. Resistance should not be greater than 7000 ohms per foot.
2. Place transmission in Neutral. Disconnect TFI wiring harness connector. Attach TFI Ignition Tester (105-000003). Connect Red lead of tester to 12 volts. Attach remote starter to "S" terminal of starter relay. While observing 2 LED lights on tester, use remote starter to crank engine. If PIP light blinks, go to step 4). If PIP light does not blink, remove distributor.
3. Remove TFI module from distributor. Using an ohmmeter, ensure all circuit resistance values are correct. See «TFI MODULE CIRCUIT RESISTANCE SPECIFICATIONS»(/ford/econoline-e350/1985-1999/remont/testing-diagnostics/#engine-controls-basic-testing). (Scheme 19) If readings are incorrect, replace TFI module. If readings are correct, check stator for open winding or short to ground. See SYSTEM/COMPONENT TESTS article. TFI MODULE CIRCUIT RESISTANCE SPECIFICATIONS TFI Terminals (1) Ohms Ground Pin - PIP More Than 500 Power Pin - PIP Input Pin Less Than 2000 Power Pin - TFI Power Less Than 200 Ground Pin - Ignition Ground Less Than 2 PIP Input Pin - PIP Less Than 200 (1) (Scheme 19)for terminal identification.
4. If PIP light did not blink in step 2), replace TFI module, and repeat step 1). If spark is still not present, replace ignition coil and module connector. If PIP light did blink in step 2), substitute ignition coil with a known working unit, and repeat step 1). If spark is now present, ensure coil secondary wire resistance is not greater than 7000 ohms per foot, and replace ignition coil.
5. If spark was not present in step 4), connect original vehicle coil and spark tester. Remove pin-in-line connector located near distributor. Crank engine while checking for spark. If spark is present, inspect PIP and ignition ground circuits to verify continuity, and repair as necessary.
6. If spark was not present in step 5), measure battery voltage with negative lead from voltmeter attached to base of distributor. Measure voltage at ignition coil positive (+) terminal. Ignition coil positive (+) terminal voltage should be at least 90 percent of battery voltage. If not, check circuitry between ignition coil and ignition switch for wear or damage. Repair as necessary.
7. If ignition coil positive (+) terminal voltage was at least 90 percent of battery voltage in step 6), remove connector from ignition module. Disconnect starter relay "S" terminal. Turn ignition on. Measure voltage at ignition module connector power terminals No. 3 and 4. (Scheme 19) See «TFI MODULE VOLTAGE TEST TERMINALS»(/ford/econoline-e350/1985-1999/remont/testing-diagnostics/#engine-controls-basic-testing). Voltage should be at least 90 percent of battery voltage.
8. If voltage is not at least 90 percent of battery voltage, check circuitry between ignition coil and ignition switch for wear or damage. Repair as necessary. If voltage was at least 90 percent of battery voltage in step 7), inspect wiring between ignition module terminal No. 2 and coil. If okay, check all related circuitry. Replace or repair as necessary.

TFI MODULE VOLTAGE TEST TERMINALS

Scheme 19

IGNITION COIL RESISTANCE

IGNITION COIL RESISTANCE

Ensure following systems and components are in good condition and operating properly before diagnosing problems in fuel injection system.

1. Battery
2. State of tune
3. Fuel delivery system
4. All wiring and vacuum connections
5. Air cleaner and ducts
6. Cooling system

Engine Does Not Crank

Check for hydrostatic lock (liquid in cylinder). Repair as needed. Check for starting and charging system problems.

Engine Cranks But Will Not Start

1. Check fuel tank contents and fuel gauge accuracy. Check for dirt, water or other contamination in fuel.
2. Check ignition system for strong secondary current at spark plugs. If no spark exists or if spark is weak, repair ignition system problem.
3. Check fuel lines and fittings for leaks. If no leaks are found, check fuel delivery system for proper pressure and volumes. Reset inertia switch (if necessary).
4. Check for a defective fuel injector or coolant temperature sensor. Ensure TPS does not stick.

Gasoline Engines

Disconnect negative battery cable. Remove fuel cap to release fuel tank pressure. Using EFI Pressure Gauge (T80L-9974-B), release fuel pressure from relief valve. Relief valve is located on fuel supply manifold.

FUEL PRESSURE

Note. Fuel pressure procedure for diesel engines is not available.

Note. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article.

Release fuel pressure. Install fuel pressure gauge. Fuel pump may be activated by grounding fuel pump lead at Self-Test connector. Using a jumper lead, ground FP terminal with ignition on. This activates fuel pump. (Scheme 20) For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. For additional circuit test information, perform related circuit test. See TESTS W/CODES article.

Scheme 20

Fuel Injector Check

1. Connect tachometer to engine. Run engine at idle. Disconnect and reconnect injectors individually. If each injector causes a momentary drop in engine speed of at least 100 RPM, injectors are providing proper fuel delivery. RPM drop should only be momentary, as ISC will attempt to re-establish correct idle RPM.
2. Replace any injectors not causing sufficient drop in engine speed. When test is complete, turn engine off. To check curb idle, refer to emission control specifications on decal in engine compartment or IDLE SPEED & MIXTURE in ADJUSTMENTS article.

Fuel Injector Circuit

Disconnect all injector harness connectors. Using digital ohmmeter, check resistance across terminals of each injector. See INDIVIDUAL INJECTOR RESISTANCE table. Disconnect injector bank harness connector, and check resistance of injector bank. See INJECTOR BANK RESISTANCE table. Repair injector bank or any injector not within specifications.

INDIVIDUAL INJECTOR RESISTANCE (1)

INJECTOR BANK RESISTANCE

Note. For further component testing and information, see TESTS W/CODES article.

INERTIA SWITCH

1. In event of a collision, electrical contacts in inertia switch open, automatically shutting off fuel pump. Fuel pump shuts off even if engine does not stop running. Engine eventually stops due to lack of fuel.
2. Engine cannot be restarted until inertia switch is manually reset. To reset inertia switch, depress button on switch. Inertia switches may be found in following locations: Aerostar & Van - On right kick panel, just forward of door opening. Bronco & Pickup - On floorboard, left of and above steering column. Explorer & Ranger - Under instrument panel, right of transmission hump.

BASE IGNITION TIMING

Note. Ignition timing is not adjustable on models with DIS or EDIS.

Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ADJUSTMENTS article. Ensure all accessories are off and transmission is in Park or Neutral. Set parking brake. Disconnect automatic parking brake release (if equipped). Ensure vehicle front wheels are in straight-ahead position and curb idle speed set to specification.

4-CYLINDER BASE IGNITION TIMING

6-CYLINDER BASE IGNITION TIMING

V6 BASE IGNITION TIMING

V8 BASE IGNITION TIMING

IDLE SPEED

Idle speed is controlled by ECA and idle speed control air by-pass valve on all engines. If control system is operating properly, engine idle RPM is fixed and cannot be changed by standard adjustments. RPM specifications for many engines are not available. A scan tester must be used on these systems because control strategy and idle speed specification are controlled by ECA. See ADJUSTMENTS article.

Before performing idle speed adjustment procedure, complete a thorough basic inspection and self-test (KOEO, KOER, Continuous Memory self-tests) to confirm operation of sub-systems contributing to idle speed control. See TESTS W/CODES article.

IDLE MIXTURE ADJUSTMENT

Note. No idle mixture adjustments are possible on any models. See TESTS W/CODES article for diagnosis of incorrect idle mixture.

THROTTLE POSITION SENSOR (TPS) ADJUSTMENT

Note. Throttle Position Sensor (TPS) on gasoline engines is not adjustable. Replace TPS if sensor is not within specifications.

TPS VOLTAGE SPECIFICATIONS (1)

FUEL INJECTION PUMP LEVER (FIPL) SENSOR ADJUSTMENT

For Fuel Injection Pump Lever (FIPL) sensor adjustment, see ADJUSTMENTS article.

SUMMARY

If no faults were found while performing BASIC TESTING, proceed to TESTS W/CODES article. If no hard codes are found in self-diagnostics or if vehicle does not have a self-diagnostic system, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

See also:
• FUEL PRESSURE SPECIFICATIONS
• TFI MODULE CIRCUIT RESISTANCE SPECIFICATIONS