Engine - Exhaust Backfires On Deceleration
86ford23 Article No. 86-3-21BACKFIRE - EXHAUST (FLUFFS) ON DECEL - 1.6/1.9L ENGINE - DIAGNOSTIC TIPS
FORD 1981-86 ESCORT, EXP
LINCOLN-MERCURY 1981-83 LN7; 1981-86 LYNX
Exhaust backfires (fluffs) may occur during sudden deceleration and/or gear shift changes.
One or more of the following causes may produce this condition. ^ Improper throttle dashpot function (collapsed or excessive clearance) ^ low curb idle speed setting ^ improper (HIC) valve function, vacuum leaks
^ migration of fuel vapor/oil into the anti-backfire valve (gulp valve).
NOTE: No damage is done to the engine, exhaust system, or vehicle due to decel exhaust fluffs.
To Resolve:
1. Verify correct throttle dashpot clearance and function. If required, reset to the specification given on the Vehicle Emission Control Information Decal.
2. Check for vacuum system leaks.
3. Check not idle compensator (HIC valve) for proper function. (See Section 3 of the Car Shop Manual Emission Diagnosis.)
4. Reset idle speeds to specification if low.
5. Road test vehicle and if condition persists, install new anti-backfire (gulp valve), part number E6EE- 9B298-AA on vehicles so equipped.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY" DLR. CODING: Basic Part No. DRIVE - Code: T1