Diagnostic Aids

1991 Mercury Tracer Base, 4D Sedan, AutomaticSECTION Diagnostic Aids
WARNING: This page is about a different car, the 1994 Mercury Topaz and 1994 Ford Tempo. However, it is still accessible from the selected car via links, so may be relevant.

To prevent replacing good components, be aware the following non-EEC related areas may be cause of problem:

  • Technician did not perform brief Wide Open Throttle (WOT) after Dynamic Response Code.
  • Engine did not go over 2000 RPM during WOT.

This test is only intended to diagnose:

  • Throttle movement (minimum 3/4 throttle).
  • RPM increase is more than 2000 RPM.

If throttle is snapped open briefly, it may not pass WOT test. Ensure throttle is depressed fully to WOT and engine speed exceeds 2000 RPM.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.