Engine - Spark Knock/Detonation
Article No:82-17-16
08/26/82
Timing Adjustment with Fixed Distributors
Ford
1983 Thunderbird
Lincoln-Mercury
1983 XR7, Continental
Light Trucks
1983 F100
Warning:
This Modification Is Authorized Only For The Listed Engines. Performing This Modification On Other Engine Calibrations Is Unauthorized And Could Create Liability Under Applicable Federal Or Local Laws.
Positive Buy" distributors are locked in position in the cylinder block and cannot be rotated to adjust timing.
"Positive Buy" ignition timing system can be identified by Torx bolt and a label on the distributor spacer.
Change ignition timing on subject vehicles by installing calibrated service distributor armatures.
Spark knock and/or detonation in subject vehicles may be serviced as follows:
1. Insure proper functioning of EGR valve and ignition system by first running diagnostic routine 215 (Page 2-18, Volume G, "1982 Car/Truck Shop Manual, Engine/Emissions Diagnosis") through Step 13 (Page 5-10).
2. Check for proper distributor orientation. Stake mark on distributor should be aligned with stake mark on cylinder block or intake manifold per the respective Car/Truck Shop Manual.
Warning:
Do Not Attempt To Rotate The Distributor To Revise Ignition Timing. The Ignition Timing Of This Engine Has Been Set At The Engine Assembly Plant With An Electronic System And Is More Accurate Than Can Be Obtained Using A Conventional Strobe Light.
Figure 21:
3. To alleviate detonation, the timing may be retarded 3 degrees by changing the distributor armature and utilizing the service part: E2PZ-1 2A099-H (Motorcraft DT-16) color light blue (Figure 21).
4. The timing may be retarded 3 degrees by replacing the distributor armature with the service armature as follows:
a. Remove the distributor cap, rotor and adapter.
b. Using a small gear puller or two screwdrivers, lift or pry the armature from the advance plate sleeve. Remove the roll pin.
c. Install the specified service armature on the advance plate sleeve, making sure the 3 groove is aligned with the slot on the sleeve and that the roll pin is engaged in the matching slot.
d. Install the distributor adapter, rotor and cap.
e. Adjust curb idle and fast idle speeds to specifications indicated on the Vehicle Emission Control Information decal.
5. Obtain an Authorized Modifications decal and list the date, dealer number, alterations performed, and change authority (TSB number and article) as shown. 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.
NOTE:
Distributor timing curves are designed to deliver maximum fuel economy and performance based on the use of 90 RON (Research Octane Number) gasoline. With this grade gasoline (equivalent to 87 Antiknock Index), certain vehicle applications may exhibit light, short duration spark knock during acceleration. This light spark knock is an indication of optimum fuel economy timing and is an acceptable operating condition.
Caution:
Replacement Of Distributor Armature For Ignition Retard Should Be Used For Customer Concerns Of Engine Detonation Only After Completion Of Diagnostics. Ignition Retard For Other Customer Concerns Is Not Approved And Could Result In Depreciation Of Fuel Economy, Performance And Driveability.
OTHER APPLICABLE ARTICLES: None
PARTS BLOCK
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP 12O99-A-82
TIME: 0.7 Hr.
DLR. CODING: Basic Part No. DETONAT Code: H9