Grand Marquis V8-302 5.0L VIN F TBI (1984)
Manifold Pressure/Vacuum Sensor: All Technical Service Bulletins
MAP Sensor - Loping/Rolling Engine Idle
Article 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.
