Engine - Tip-In Stumble After Prolonged Deceleration
85ford19Article No. 85-19-21
TIP-IN STUMBLE AFTER PROLONGED DECELERATION - ALL 2.0L/2.3L WITH MCU
LIGHT TRUCK 1983-84 RANGER
CALIBRATIONS: All 2.0L/2.3L with MCU
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.
The following procedure supersedes the original TSB Article 85-16-18 dated August 14, 1985. The electrical canister purge control valve must remain electrically connected to allow for proper completion of the MCU system self check. Only vacuum hose connections can be disconnected as shown.
Concern vehicles may exhibit tip-in stumbles after prolonged deceleration. This may be caused by a possible overlap in component function which can allow the electric purge solenoid to remain actuated for a short period of time while the carburetor bowl vent is opened. This can result in a slight vacuum in the carburetor bowl causing a lean condition. This lean condition results in a stumble on tip-ins after a prolonged deceleration.
To resolve this condition, the following procedure is recommended.
Figure 25 - Vacuum Hose Routing Schematic:
Figure 26 - Vacuum Hose Routing Schematic:
Remove only the vacuum connections on the electric solenoid (E1TE-9C915-BA) ensuring that the electrical connections remain intact, and secure the valve to its wiring loom. Electrical connections must remain intact to allow the MCU system self check to be run as required. Replace the electrical purge control valve with a mechanical purge control valve (9B963) and a vacuum delay valve (12A091). Add a "T" fitting on the hose coming from the EGR BPT and route the vacuum hose to the mechanical purge control valve and the vacuum delay valve. Hose routing is shown on the schematics (Figures 25 and 26).
Authorized Modifications Decal:
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
E3TZ-9B963-A Purge Control Valve C
E3AZ-12A091-E Vacuum Delay Valve R
373846-S 3/16" Vacuum Tee BR
OTHER APPLICABLE ARTICLES: Supersedes 85-16-18
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9915A85
TIME: 0.4 Hr. DLR. CODING: Basic Part No. 9C915 - Code: M2