MAP Sensor - Loping/Rolling Engine Idle
84ford1Article No. 84-26-4
IDLE - LOPING (ROLL) - 5.0L - PARK OR NEUTRAL
FORD 1984 CROWN VICTORIA
LINCOLN-MERCURY 1984 GRAND MARQUIS
CALIBRATIONS: All with C.F.I.
A loping or oscillating condition (100 rpm or more variance) during idle in "Park" or "Neutral" can be serviced by installing a vacuum regulator in the map sensor line.
1. Perform visual check and vehicle preparation by referring to EEC IV Quick Test procedure, in 1984 Car Emission Diagnosis Shop Manual.
2. Adjust curb idle speed to 550 rpm. (Refer to procedure on Engine Emission Control Information Decal).
3. Perform EEC IV Quick Test. Measure MAP sensor voltage output (use MAP sensor tester part no. 105- 00001); refer to instructions packaged with tester. If both test o.k., proceed to step #4.
4. Disconnect A/C clutch wire and start engine. Allow engine to run until stabilized temperature is reached. (Be sure transmission is in "Park" position).
5. With engine idling and with heat/AC selector in "Off" position, wait until the throttle kicker deenergizes (approximately 65 seconds).
6. While running engine at part throttle (1500 rpm), with transmission in "reverse" and with heat/AC selector in "Mix" position, the throttle kicker should become energized. Maintain this condition for 1 minute.
7. Return engine to closed throttle position and with transmission in "Park" observe idle quality for 3 minutes.
8. If loping condition is present (100 rpm or more variance), install new vacuum regulator as follows:
A. Obtain a connector (pan no. 38004-S) and attach the 5/32" side to a 5/32 x 2.0" vacuum hose. Attach hose to the manifold ("Man") side of the new vacuum regulator.
B. Obtain a connector (part no. 38004-S) and attach the 5/32" side to a 5/32 x 3.5" vacuum hose. Attach hose to the delay ("DELAY") side of the new vacuum regulator.
Figure 5:
C. With the regulator and hose assembly (fabricated in steps A & B) splice the MAP sensor 7/32" vacuum hose, 4.0" from MAP sensor and connect it to the 3.5" hose (step B) on regulator (Figure 5).
D. Connect the 5/32" x 2.0" (opposite hose on vacuum regulator, step A) to spliced hose muted to intake manifold vacuum (Figure 5).
NOTE: MAP sensor is located on the right hand inner fender.
9. Repeat step #4-7 insure condition has been alleviated.
10. Check all vacuum hose connections and routings to ensure there are no vacuum leaks or potential obstructions.
11. Obtain and install an Authorized Modifications Decal, denoting the above changes.
CAUTION: WHENEVER EEC QUICK TESTS ARE RUN ON THESE VEHICLES WITH A NEWLY INSTALLED VACUUM REGULATOR, THE FILTER ON THE REGULATOR MUST BE REMOVED AND
REPLACED WITH A 5/32 VACUUM CAP FOR THE DURATION OF THE TEST. AFTER COMPLETION OF THE QUICK TEST, REMOVE THE VACUUM CAP AND REINSTALL THE FILTER ON THE VACUUM REGULATOR. IF THIS IS NOT DONE FALSE CODES COULD RESULT. THIS INFORMATION MUST BE INCLUDED ON THE MODIFICATION DECAL.
Obtain an Authorized Modifications decal and list the date, dealer number and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information decal suitable for installing the Authorized Modifications decal. Clean the area, install the decal and cover it with a clear plastic decal shield.
PART NUMBER PART NAME CLASS
383004-S Connector Vacuum SG
E4SZ-9F490-A Regulator Vacuum C
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9490A84
TIME: 1.4 Hrs. DLR. CODING: Basic Part No. DRIVE Code: H7