Idle circuitry is rarely a problem on any engine, diesel or gas. But having a rough idle, seeing a loss of power output, witnessing poor fuel economy as well as an increased use of engine oil can all be caused, says Ford Motor Company technicians by aged, worn, cracked or deteriorated fuel injection nozzle 0-rings. This is standard fare for any fuel-injected engine as the rubber 0-rings always weather with age and heat. This data is in its Technical Service Bulletin number 98-23-13 and covers 1994-1998 engines.
Adding further to the dilemma, this situation cannot be detected with any of the electronic testers. Nor will a trouble light find its way to the gauge cluster. If you find that this is your problem, Ford 0-ring kit, part number F8TZ-9229-AA is the remedy. You may also wish to check and/or replace the fuel filter - per the Ford Service Manual.
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