Engine - Hesitation/Stumble/Stall/Detonation
87ford2
Article No. ^ HESITATION - 2.3L OHC WITH AUTOMATIC OR
87-12-20 MANUAL TRANSMISSION
^ STUMBLE - 2.3L OHC WITH AUTOMATIC TRANSMISSION - VEHICLE RUNS LEAN
^ STALL - 2.3L OHC WITH AUTOMATIC TRANSMISSION - VEHICLE RUNS LEAN
^ DETONATION - 2.3L OHC WITH AUTOMATIC AND MANUAL TRANSMISSION -
EXCESSIVE CARBON BUILDUP
LIGHT TRUCK: 1985-86 RANGER 1986 AEROSTAR
ISSUE: Detonation, hesitation, stumble, or stall on acceleration during warm weather (above 50~F/10~C) or while driving on hilly roads may be caused by carbon buildup on various engine components due to overfill of the engine oil. Hesitation, stumble, or stall on acceleration concerns could also be caused by a lean engine calibration that is unable to perform satisfactorily within normal engine component tolerances.
ACTION: To correct these concerns, use the following diagnostic and service procedures to assure proper engine oil levels and determine if it is necessary to revise the engine calibration.
NOTE: A detonation concern cannot be corrected by installing a new EEC IV processor. Do not proceed further than Step 3 for detonation concerns.
1. Perform self-test and service as required.
2. Install oil level tube assembly and/or oil dipstick.
NOTE: Two oil level tube assembly mounting locations have been used since 1985.
1985-86 Built 03/15/85 To 06/04/86 -
Oil Level Tube Assembly
A. If vehicle uses the side of intake manifold as a mounting surface for old oil level tube assembly, then disconnect old tube assembly and install the new tube assembly (E6TZ-6754-F) using same mounting hole and bolt.
Figure 30 - Article 87-12-20:
If old oil level tube assembly is mounted on bottom of intake manifold, remove oil tube assembly and install new oil level tube assembly (E6TZ-6754-F) TO THE SIDE of intake manifold using a new (N605812-S2) bolt, see Figure 30.
NOTE: Mounting bracket hole must be enlarged to fit larger diameter (N605812-S2) bolt. This bolt has a torque-retention thread.
CAUTION: New oil level tube assembly must be fully engaged into block for oil dipstick to indicate proper engine oil level. It must be bottomed out and sealed as shown in Figure 30.
B. Insert new oil dipstick (E7TZ-6750-G).
C. Drain oil from engine and replace oil filter.
D. Add five (5) quarts of oil to engine, Run engine five (5) minutes, shut off engine, and let stand five (5) minutes. Check engine oil level reading using new oil dipstick.
1986 Built After 06/05/86 - Oil Dipstick
A. Remove old engine oil dipstick and insert new oil dipstick (E7TZ-6750-G).
B. Drain oil from engine and replace oil filter.
C. Add five (5) quarts of oil to engine. Run engine five (5) minutes, shut off engine, and let stand five (5) minutes. Check engine oil level reading using new oil dipstick.
3. Remove excessive carbon deposits.
A. Drain engine coolant and save for reuse. Remove head and intake valves. Refer to appropriate 1987 Light Truck/Aerostar Shop Manual.
B. Clean combustion chamber, (head and piston), intake valves and intake ports of carbon deposits using Combustion Chamber Cleaner (D9AZ-19579-B).
C. Reinstall heads.
D. Clean throttle body to remove any oil deposits. See TSB 86-20-6.
E. Reset throttle body hard stop (idle speed) to 625 +/- 25 RPM. Use the 1986 Engine/Emission Diagnosis Shop Manual, Volume H, Page 4-45 (TSB 86-19-15, insert) revised procedure.
NOTE: The first three steps of this TSB will normally correct all four (4) of the concerns. If the hesitation, stumble, or stall on acceleration concerns have not been corrected on vehicles equipped with automatic transmissions, proceed to Step 4.
4. Install a new EEC IV processor (E7TZ- 12A650-JA).
5. Install a new throttle position sensor (E6ZZ- 9B989-A).
NOTE: Vehicle may already have this throttle positioning sensor installed.
6. Install map sensor (E7FZ-9F479-A).
NOTE: 1987 diagnostic procedures are required when servicing this system.
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
E7TZ-12A650-JA EEC IV Processor B
E6ZZ-9B989-A Throttle Position Sensor B
E7FZ-9F479-A MAP Sensor B
E5TZ-6079-C Gasket Kit AM
E6TZ-6754-F Oil Tube Assembly C
E7TZ-6750-G Oil Dipstick C
N605812-S2 Bolt - Package of 4 S
D9AZ-19579-B Carburetor and AM
Combustion Chamber
Cleaner
OTHER APPLICABLE ARTICLES: 87-8-18, 87-7-23, 86-20-6, 86-19-15
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual
OPERATION: SP871220A - Steps 1 through 3
TIME: 8.2 Hrs. - Vehicles built 03/18/85 to 06/04/86
7.8 Hrs. - Vehicles built after 06/05/86 to 10/20/86
OPERATION: SP871220B - Steps 4 through 6
TIME: 1.8 Hrs.
DLR. CODING: Basic Part No. DRIVE - Code: P2