Tempo L4-140 2.3L CFI (1985)
Air Injection Bypass Valve: All Technical Service Bulletins
Engine - Backfire On Deceleration
BACKFIRE ON DECEL - 2.3L HSC - WITH CARBURETOR AND MTX - CANADIAN CALIBRATION ONLY
Article No. 88-2-12
FORD:
1985-86 TEMPO
LINCOLN-MERCURY: 1985-86 TOPAZ
CALIBRATIONS: 5-25G-R00 5-25G-R13 (Canadian calibration)
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.
ISSUE:
Engine backfiring during decel or during transmission downshifting on Canadian calibrated vehicles may be caused by a delayed vacuum
signal to the thermactor air bypass valve. The delayed signal allows the air pump to dump air into the exhaust system creating a backfire
condition.
ACTION:
To correct this, modify the vacuum hoses using the following service procedure.
FIGURE 16
1.
Locate rubber connector that is attached to the EGR solenoid valve, Disconnect nylon vacuum elbow that is attached to RED
vacuum tubing from rubber connector, Figure 16.
