Lack/Loss Of Power

WARNING: This page is about a different car, the 2002 Ford Pickup and 2002 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The PCM is equipped with an over RPM/speed limit function. If programmed speed is exceeded, fuel delivery will shut off and DTC P1270 will be set in PCM memory. If vehicle is equipped with a Knock Sensor (KS), a lack of power may result when vehicle is operated with a breakout box installed at PCM. KS circuits are not shielded in breakout box, and KS signal noise may be noticed by PCM. If this happens, spark timing will be retarded and a lack of power may result.

Check air intake system. See TEST HU: AIR INTAKE SYSTEM under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.
Check secondary ignition system. See TEST JB: SECONDARY IGNITION under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.
Check fuel delivery system. See TEST HC: FUEL DELIVERY SYSTEM under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - BI-FUEL article.
Check exhaust system for restriction. See TEST HF: CATALYST EFFICIENCY MONITOR & EXHAUST SYSTEMS under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.
Check EGR system. See TEST HE: EGR SYSTEM under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.
Check engine mechanical condition. Check compression, camshaft, valve train components, etc., and repair as necessary. See appropriate article in ENGINES.
On A/T models, check ATF level, throttle linkage and A/T Torque Converter Clutch (TCC) solenoid or circuits. See FORD 4R70W DIAGNOSIS or FORD 4R100 DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.
Check for dragging brakes and repair as necessary. See DISC - BLACKWOOD & F150 PICKUP article in BRAKES.
Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, access PCM and select DPFEGR (if equipped), LONGFT1 and LONGFT2 PIDs from PID/DATA MONITOR & RECORD menu. See PIN VOLTAGE/PID VALUE CHARTS - TRUCKS article. DPFEGR PID value should be within .15 volt of Key On Engine Off (KOEO) value. If LONGFT1 or LONGFT2 PID value is low (-20 percent), concentrate checks in areas that would cause engine to run rich. If LONGFT1 or LONGFT2 PID value is high (+20 percent), concentrate checks in areas that would cause engine to run lean.
Check Mass Air Flow (MAF) sensor and related circuits. See TEST DC: MASS AIRFLOW SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.

Additional Checks

Check customer driving habits. Check for correct PCM Vehicle Identification (VID) block information. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE under PROGRAMMING PCM in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article. Check charging system. See GENERATORS & REGULATORS - BLACKWOOD, EXPEDITION, F150 & NAVIGATOR article in STARTING & CHARGING SYSTEMS. Ensure engine RPM/speed limiting functions of PCM are operating properly. Check for incorrect high vehicle speed signal. If no problems are indicated, return to SYMPTOM DIAGNOSIS to identify any additional symptoms or check for intermittent faults. See TEST Z: INTERMITTENT under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.