1978 Plymouth Arrow Base, Automatic TransFACTORY OEM SERVICE PROCEDURE

1978 Models

  1. With engine idling, disconnect Yellow stripe hose form EGR valve and connect a hand-held vacuum pump to nipple. While opening sub EGR valve by hand, apply 6 in. Hg of vacuum. If idle becomes rough or engine stalls, the primary valve is operating properly. If not, replace dual EGR valve.
  2. Remove hand-held vacuum pump and reconnect Yellow stripe hose. Remove Green stripe hose from EGR valve and connect vacuum pump to hose. Apply 6 in Hg. of vacuum while opening sub EGR valve by hand. If idle becomes rough, the secondary valve is operating properly. If not, replace dual EGR valve.
  3. Ensure that sub EGR valve moves smoothly when pulled by hand. If valve is hard to move, remove sub EGR valve and check for carbon deposits. Clean or replace valve, as required.
    Fig 1: 1976-77 Exhaust Gas Recirculation System
    G09313038Courtesy of CHRYSLER GROUP, LLC
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When to See a Mechanic

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

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

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