Spark Plugs - Spark Knock

Article No.
84-18-17

SPARK KNOCK - 5.0 HO SPARK PLUGS - 5.0 HO - EROSION PISTONS - 5.0 HO - POSSIBLE DAMAGE

FORD:
1984 MUSTANG, LTD

LINCOLN-MERCURY:
1984 CAPRI, MARQUIS

CALIBRATIONS: All with 5.0 HO C.F.I.

Spark Plug erosion, detonation and sometimes piston damage (from resultant detonation and over-heat conditions) may be alleviated by resetting the fuel pressure and ignition timing and installing cooler spark plugs.

1. Allow for engine break-in prior to high speed operation.
2. Check for kinking of the map sensor vacuum hose (located on left hand strut tower). See article in TSB # 84-13. Kinking of hose can cause map sensor to function improperly, which could create driveability concerns.
3. Replace spark plugs (ASF-52) with spark plugs (ASF-42), which are of a cooler heat range.
4. Check and reset, if necessary, the fuel pressure regulator to nominal setting of 39.3 psi. This will reduce potentially excessive lean condition, in cylinders no. 1 and 2. (Refer to 1984 Car Shop Manual Section 24-03).
5. On LTD Police Vehicles Only:

a. Increase fuel pressure setting 40 KP (5.8 PSI) from as received setting (Step # 4).
b. Retard engine ignition timing 3~. This can be achieved by installing a 3~ retard octane rod, (part no. E3EE-12A335-BA) according to procedure outlined in the 1984 Car Shop Manual (Section 23).





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

E3FZ-12A335-B 3~ Retard Octane Rod B
ASF-42 Spark Plug A

OTHER APPLICABLE ARTICLES: 84-13
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.

OPERATION: SP12335A84
TIME: 0.8 Hr.

DLR. CODING:
Basic Part No. Code:
DRIVE: H9