LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chrysler >> 1988 >> New Yorker Base >> Repair and Diagnosis >> Engine Performance >> System >> EGR System >> Testing >> System Functional Check >> 5.2L
April 5, 2026: LEMON Manuals is launched! Read the announcement.

System Functional Check: 5.2L

  1. Warm engine to operating temperature, and let idle at least 2 minutes after warm-up in Park or Neutral. Disconnect hose at EGR valve and attach a vacuum gauge to hose.
  2. Open throttle quickly several times. A fluctuation of several in. Hg of vacuum should be observed during throttle movement. Disconnect vacuum gauge. Attach a vacuum pump to the EGR valve. With engine running, apply 10 in. Hg vacuum to the valve. The engine speed should drop several hundred RPM, stumble or stall.
  3. Disconnect the vacuum pump and reconnect vacuum hose to EGR valve. If system operated as described, system is operating correctly. If system did not operate as described, remove connector from charge temperature sensor. Using an ohmmeter, check sensor resistance. See CHARGE TEMPERATURE SENSOR RESISTANCE table.
    CHARGE TEMPERATURE SENSOR RESISTANCE

    Temperature °F (°C) Resistance: Ohms
    -40 to 20 (-40 to -7) 382,000-22,000
    50-100 (10-38) 36,000-3300
    140-245 (60-118) 3900-176
  4. If resistance is not as specified, replace sensor. If resistance is okay, repair wiring between computer and sensor for an open or short circuit. With engine cold and not running, connect a voltmeter to Gray wire at EGR solenoid. Set parking brake and start engine.
  5. With engine temperature less than 70°F (21°C) for 2-Bbl. models and less than 50°F (10°C) for 4-Bbl. models, voltmeter should read zero to one volt. If voltage reading is more than one volt, turn engine off. Disconnect computer 12-pin connector. Connect voltmeter to connector cavity No. 7 and ground. Turn ignition switch to "RUN" position.
  6. Voltmeter reading should be within one volt of battery voltage. If voltage reading is okay, replace computer. If there is zero volts, repair open circuit in wiring harness to ignition switch.
  7. On 5.2L 4-Bbl. models, remove venturi vacuum hose from carburetor. With engine at idle, apply 1-2 in. Hg vacuum to vacuum hose. Engine speed should drop at least 150 RPM and EGR valve stem should visibly move at least 1/8".
  8. If this does not occur, replace vacuum amplifier. If system works properly, check carburetor for plugged vacuum tap. Use carburetor cleaner to clean passage and blow through with compressed air.
  9. On 5.2L 2-Bbl. models, remove ported vacuum hose from carburetor. With engine at idle, apply at least 5 in. Hg vacuum to vacuum tap on carburetor. If vacuum does not bleed off, check carburetor for plugged vacuum tap. Use carburetor cleaner to clean passage and blow through with compressed air.
    NOTE: DO NOT use drill or wire to clean carburetor control passages, as calibration of control orifices may be changed, resulting in unsatisfactory vehicle operation.
  10. On 5.2L 4-Bbl. models, if engine will not idle, or if engine stalls or idles very rough or slow, disconnect and plug EGR vacuum hose. Recheck idle. If idle is now okay, replace amplifier. If vacuum hose removal does not correct problem, remove EGR valve. Inspect valve and clean as necessary. Replace EGR valve as necessary.
  11. If there is poor Wide Open Throttle (WOT) performance, disconnect and plug EGR hose. Road test vehicle. If performance is restored, replace amplifier.
scientia non olet · About LEMON Manuals