Engine Controls - Basic Testing - Diesel (VIN K & M) Ford Pickup F250

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 appropriate VACUUM DIAGRAMS article in this section to verify routing and connections (if necessary). Refer to the following menu. Inspect air induction system for possible vacuum leaks.

Compression

To check compression, preform the crankcase pressure test. Remove crankcase depression regulator valve and securely plug opening to prevent blow-by. Remove oil filler cap and install Pressure Test Kit (014-00761) and adapter (5631). Ensure dipstick is seated in dipstick tube. Run engine at 3300 RPM no load, with transmission in Neutral. Record pressure reading. Pressure should not exceed 6 in. H2O at 3300 RPM.

Exhaust System Backpressure

Visually check exhaust system for dents or kinks which could cause restriction.

PRELIMINARY CHECKS

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 starting and charging system.

Engine Cranks But Will Not Start

1. Check fuel tank contents and fuel gauge accuracy. Check for dirt, water or contamination in fuel.
2. 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).

FUEL PRESSURE

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

Note. For fuel pressure procedure for diesel engines, see the SYSTEM/COMPONENT TESTS - DIESEL in this section. Also see FUEL PUMP PERFORMANCE table.

Scheme 279

FUEL PUMP PERFORMANCE

Fuel Injection Nozzle Check

Where ideal conditions of good combustion, specified engine temperature control and absolutely clean fuel prevail, nozzles require little attention. Nozzle trouble is usually indicated by one or more of the following symptoms

1. Smoky exhaust (black)
2. Loss of power
3. Misfiring
4. Increased fuel consumption
5. Combustion knock
6. Engine overheating

When faulty nozzle operation is suspected on an engine that is misfiring or puffing black smoke, a simple test can be made to determine which cylinder(s) is causing the problem. Run the engine at the RPM which makes the problem most pronounced. Momentarily loosen the high-pressure fuel inlet line connection on one nozzle assembly one-half to one turn. Then, tighten connection to specification. Check each cylinder in the same manner. If one nozzle is found where loosening makes no difference in the misfiring, or the puffing black smoke stops, that nozzle should be tested. Test only the suspect nozzle(s).

NO-START DIAGNOSIS

Note. For diesel information, see appropriate TESTS W/O CODES article in the ENGINE PERFORMANCE section below.

INJECTION TIMING - STATIC TIMING

Align the timing mark on the injection pump with the timing mark on the pump mounting adapter.

INJECTION TIMING - DYNAMIC TIMING

Ensure idle speed and injection timing are set to specification. See the DYNAMIC INJECTION TIMING table. For adjustment procedures, refer to the ADJUSTMENTS - DIESEL article in this section. Ensure all accessories are off and transmission is in Park or Neutral. Set parking brake. Ensure vehicle front wheels are in straight-ahead position and idle speed is correct.

Note. Always refer to Emission Control Label in engine compartment before attempting service. If manual and label differ, always use emission label specifications.

DYNAMIC INJECTION TIMING SPECIFICATIONS (1)

Curb Idle Speed Adjustment

Place transmission in Neutral or Park. Bring engine up to normal operating temperature. Idle speed is measured with M/T in Neutral and A/T in Drive. Ensure that curb idle adjusting screw is against the stop. If not, correct vehicle linkage. Check curb idle speed, using Rotunda (055-00108). Curb idle speed is 600-700 RPM, or as specified on the Vehicle Emissions Control Information (VECI) decal. Adjust to specification using idle speed adjusting screw. (Scheme 280) Place transmission in Neutral or Park. Rev engine momentarily. Place transmission in specified gear and check curb idle RPM. Adjust again if necessary.

Scheme 280

Fast Idle Speed Adjustment

Adjustment is made at Cold Idle Solenoid. Place transmission in Neutral or Park. Start engine, and bring up to normal operating temperature. Disconnect fast idle solenoid from wiring harness. Apply battery voltage to solenoid to activate it. Rev engine momentarily to set solenoid to activate it. Check fast idle speed setting. Fast idle RPM should be 800-850 RPM. Adjust to specification by turning solenoid plunger in or out. (Scheme 280) Rev engine momentarily and check fast idle RPM. Adjust as necessary. Remove battery voltage from solenoid connector and connect to wiring harness.

IDLE MIXTURE ADJUSTMENT

Note. Idle mixture is not adjustable. If idle mixture is incorrect, see appropriate G - TESTS W/O CODES - EEC-IV (DIESEL) article in the ENGINE PERFORMANCE section.

SUMMARY

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

1. «TESTS W/O CODES»(ref-22980) (for Econoline/Club Wagon)
2. «TESTS W/O CODES»(ref-22976) (for "F" Pickup)

See also:
• SYSTEM/COMPONENT TESTS - DIESEL
• ADJUSTMENTS - DIESEL
• FUEL PUMP PERFORMANCE