Possible Causes & Corrections

Check for restricted exhaust system.
Check ignition system for bare or shorted wires, incorrect pick-up coil resistance, loose ignition coil connections or moisture in distributor cap (if equipped).
Using Spark Tester (J-26792), check for adequate spark output.
Check ignition control circuit for short to ground.
Remove spark plugs. Check for wet/fouled spark plugs, cracks in porcelain, improper gap, burned electrodes or heavy carbon deposits.
Check for shorts by misting plug wires with water.
Check fuel pump relay. Connect test light between fuel pump test terminal and ground. Turn ignition on. Test light should illuminate for 2 seconds. If test light does not illuminate, check fuel pump relay. See the SYSTEM/COMPONENT TESTS article. For location of fuel pump test connector, see the SYSTEM/COMPONENT TESTS article.
Check for poor fuel quality or water-contaminated fuel.
Check for correct fuel pressure at all speeds and engine RPMs.
Check for a faulty in-tank fuel pump check valve (if equipped). A faulty check valve allows fuel in lines to drain back to tank after engine is stopped.
Check EGR operation.
Ensure ECT circuit or sensor resistance is not too high. See the SENSOR RANGE CHARTS article.
Ensure TP sensor does not stick or bind. A sticking throttle shaft or binding linkage may cause a high TP sensor voltage (open throttle indication). PCM will not control idle if high voltage is sensed.
Check Idle Air Control (IAC) system. Check for foreign material in IAC bore.
Ensure correct PROM is installed in vehicle. Check with dealer for latest application information.