Ford F150 Pickup. Instruction — part 1218

BASE IGNITION TIMING

FUEL SYSTEMS

FUEL INJECTORS

FUEL INJECTOR RESISTANCE

FUEL PUMP

FUEL PRESSURE SPECIFICATIONS

IDLE SPEED & MIXTURE

NOTE:

On all models with distributorless electronic ignition, manufacturer does not
recommend checking ignition timing, as faulty readings are common and timing
is not adjustable.

Application

Degrees BTDC

All

10

Application

(1)

Resistance - Ohms

4.2L

11.4-12.6

4.6L

13.8-15.2

5.4L

13.8-15.2

5.4L CNG

4-6

6.8L

11-18

(1)

Resistance values are for a single injector.

NOTE:

Fuel pump performance is a measurement of fuel pressure and volume
availability, not regulated fuel pressure.

Application

(1)

psi (kPa)

CNG Engines

80-120 (276-827)

Diesel Engine

6.0L

45-55 (310-379)

7.3L

45-80 (310-552)

Gasoline Engines

4.2L, 4.6L & 6.8L

30-45 (207-310)

5.4L

30-55 (207-379)

(1)

With key on and engine off and fuel pump running.

NOTE:

Idle speed and mixture are not adjustable. For additional information, see
appropriate THEORY & OPERATION article.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Service & Adjustment Specifications - Excursion & Pickup

THROTTLE POSITION SENSOR

TP SENSOR OUTPUT

NOTE:

Throttle Position (TP) sensor is not serviceable. TP sensor may also be referred
to as Accelerator Pedal (AP) sensor. If TP sensor service is required, perform
TP sensor related system test. See appropriate SELF-DIAGNOSTICS article.

Throttle Angle Degrees

(1)

Volts

Clockwise

20

1.00

40

2.00

60

3.00

80

3.80

100

4.65

Counterclockwise

0

1.00

-20

2.00

-40

3.00

-60

3.80

-80

4.65

(1)

Throttle position may vary by 6 percent.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Service & Adjustment Specifications - Excursion & Pickup

2003 ENGINE PERFORMANCE

Basic Diagnostic Procedures - Trucks - Except Diesel

INTRODUCTION

The following diagnostic steps will help prevent overlooking a simple problem. The first step in diagnosing any
driveability problem is verifying the symptom(s) with a test drive under the conditions the problem reportedly
occurred.

Before proceeding with diagnostics, check for applicable Technical Service Bulletins (TSBs). If there are no
applicable TSBs, perform QUICK TEST under SELF-DIAGNOSTICS - EEC-V - CNG, FLEX-FUEL &
GASOLINE to identify Diagnostic Trouble Codes (DTCs). If no DTCs are present or only pass codes are found
during self-diagnostics and symptom is present, proceed to TROUBLE SHOOTING - NO CODES - EEC-V -
CNG, FLEX-FUEL & GASOLINE article for diagnosis by symptom.

PRELIMINARY INSPECTION & ADJUSTMENTS

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.
Inspect air induction system for possible vacuum leaks.

MECHANICAL INSPECTION

Compression

Check engine compression with engine at normal operating temperature, all spark plugs removed (on dual
plugs, remove exhaust side only), and throttle wide open. Ensure crankcase is full and oil is of correct viscosity.
With compression gauge installed, use remote starter switch to crank engine. Crank engine at least 5
revolutions, and record highest reading. Repeat procedure for all cylinders, using approximately same number
of revolutions. Lowest compression reading should not be less than 75 percent of highest compression reading.
No cylinder compression reading should be less than 100 psi (7 kg/cm

2

).

Exhaust System Backpressure

NOTE:

References to Econoline include Cutaway and RV Cutaway. References to F250-
550 include Cab & Chassis.

WARNING:

Because fuel injectors on many models are triggered by the ignition
switch, DO NOT use ignition switch during compression tests on fuel
injected vehicles. Use a remote starter to crank engine to prevent fire
hazard or engine oiling system contamination.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Trucks - Except Diesel

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Trucks - Except Diesel

Using a vacuum or pressure gauge, check exhaust system. Remove Heated Oxygen Sensor (HO2S) or air
injection check valve (if equipped). Connect a 0-5 psi pressure gauge. Backpressure should be less than 3 psi at
idle and less than 8 psi at wide open throttle. If exhaust system backpressure is greater than specified, 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.

FUEL SYSTEMS

PRELIMINARY CHECKS

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

z

Check battery and charging system condition.

z

Check all wiring and vacuum connections.

z

Check air cleaner and ducting.

z

Check state of tune.

z

Check fuel delivery system.

z

Check cooling system.

z

Check inertia fuel shutoff switch.

z

Check for blown head gasket (liquid in cylinder).

z

Check fuel tank contents and fuel gauge accuracy.

z

Check for dirt, water or other contamination in fuel.

z

Check fuel lines and fittings for leaks.

z

Check fuel delivery system for proper pressure and volume.

z

Check for inoperative fuel injectors.

z

Check for improperly installed electronic equipment such as anti-theft system, CB radio, cellular
telephone or stereo.

FUEL SYSTEM PRESSURE RELEASE

NOTE:

For fuel system diagnosis on Natural Gas Vehicles (NGV), see TEST HA:
NATURAL GAS FUEL CONTROL and TEST HB: NATURAL GAS FUEL DELIVERY
SYSTEM in SELF-DIAGNOSTICS - EEC-V - CNG, FLEX-FUEL & GASOLINE
article or TEST H: FUEL CONTROL in SELF-DIAGNOSTICS - EEC-V - BI-FUEL
article.

WARNING:

Always relieve fuel pressure before disconnecting any component under
fuel pressure. DO NOT allow fuel to contact engine or electrical

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Trucks - Except Diesel