Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Air Injection Bypass Valve: Customer Interest
Air Injection - Heavy White Exhaust Smoke
Article No. 83-6-24
SMOKE FROM EXHAUST - 4.9L - WHITE SMOKE AT IDLE
LIGHT TRUCKS E, F & BRONCO
A heavy white exhaust smoke during extended idle after a stabilized drive may be caused by the thermactor air system not dumping (venting) the
thermactor air during an extended idle (over 150 seconds). This causes the catalyst to burn off fuel residue, producing a white smoke.
Perform the following service procedures:
1.
Check if all vacuum lines are properly routed, all connections are secure and vacuum hoses are not crimped or broken.
FIGURE 25
