A/T Throttle Valve - Spark Knock/Shudder
84ford3Article No. 84-23-7
SPARK KNOCK - 5.0L CFI - DURING ACCELERATION
SHUDDER - 5.0L CFI - DURING ACCELERATION
FORD 1984 CROWN VICTORIA
LINCOLN-MERCURY 1984 GRAND MARQUIS
CALIBRATIONS: 5.0 with CFI
Engine and/or driveline shudder during acceleration, sometimes accompanied by spark knock, can be serviced by adjusting the transmission throttle valve pressure to specifications and, if necessary, installing an octane rod.
The condition is more pronounced during moderate-toheavy acceleration and under low RPM/high load conditions.
Most vehicles affected operate in regions of sea-level altitude and where ambient temperatures and humidity are high.
1. Perform EEC IV Quick Test, by referring to 1984 Emission Diagnosis Shop Manual, to assure that no other faults are present.
2. Determine that the MAP sensor (located on right hand inner fender) has a yellow dot on the top of sensor; if not, replace with a yellow dot MAP sensor part number E43Z-9F479-B only.
3. If spark knock is evident only in third gear at speeds of 17-20 mph and/or fourth gear at speeds of 35-40 mph, then verify that the throttle valve (TV) pressure is set to the nominal specification (35 PSI). Refer to the adjustment procedure in the 1984 Car Shop Manual (Page 17-20-6).
4. If detonation is still present, refer to procedure in TSB 84-13-8 which pertains to engine octane adjustment.
PART NUMBER PART NAME CLASS
E43Z-9F479-B MAP Sensor A
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP77332A84
TIME: 1.4 Hrs. DLR. CODING: Basic Part No. DRIVE Code: H9