2003 ENGINE PERFORMANCE
Trouble Shooting - No Codes - Bi-Fuel - Gasoline/LPG
INTRODUCTION
This article contains bi-fuel system trouble shooting tests only. For gasoline or flex-fuel vehicles with EEC-V
systems, see TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article. Always
retrieve Powertrain Control Module (PCM) DTCs before Alternate Fuel Control Module (AFCM) DTCs. If any
network "U" type DTCs are present, repair prior to PCM DTCs. If PCM DTCs are retrieved, go to
DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL &
GASOLINE article and service DTCs as necessary. If AFCM DTCs are retrieved, go to DIAGNOSTIC
TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - BI-FUEL - GASOLINE/LPG article. If no
DTCs are present, perform SYMPTOM DIAGNOSIS under SYMPTOMS to diagnose driveability problems
existing when a hard fault code is not present. If all symptom tests check okay, perform INTERMITTENT
PROBLEM DIAGNOSIS under INTERMITTENTS.
For specific system or component testing procedures, see SYSTEM & COMPONENT TESTING - BI-FUEL
- GASOLINE/LPG article. For specifications, seeON-VEHICLE ADJUSTMENTS - TRUCKS article or
appropriate SERVICE & ADJUSTMENT SPECIFICATIONS article.
PRELIMINARY CHECKS
Check for vacuum leaks. Check air intake duct and air filter. Check ignition wiring. Check alternate fuel tank(s)
for adequate LPG level. Check wiring harness connector for poor connections. Check PCM, compuvalve,
sensors and actuators for damage. Check engine coolant for proper level and mixture. Check A/T fluid for
proper level and quality. Make all repairs before performing SYMPTOM DIAGNOSIS .
SYMPTOMS
NOTE:
Some driveability problems may have been corrected by manufacturer with a
revised computer calibration chip or computer control unit. Check with
manufacturer for latest chip or computer application.
NOTE:
Bi-fuel systems operating in Alternate (ALT) fuel mode (LPG) are gaseous-type
fuel systems that require a higher spark plug firing voltage to ignite fuel and
puts a higher load on vehicle ignition system. A secondary ignition system may
not operate well or may exhibit problems when running on alternate fuel; such
as backfiring or stalling, even though no problems exist while running on
gasoline.
CAUTION: When battery is disconnected, vehicle computer may lose memory data.
Driveability problems may exist until computer systems have completed a
relearn cycle. Before disconnecting battery, see COMPUTER RELEARN
PROCEDURES article in GENERAL INFORMATION.
2003 Ford Pickup F150
2003 ENGINE PERFORMANCE Trouble Shooting - No Codes - Bi-Fuel - Gasoline/LPG
2003 Ford Pickup F150
2003 ENGINE PERFORMANCE Trouble Shooting - No Codes - Bi-Fuel - Gasoline/LPG