Air Injection - Heavy White Exhaust Smoke
83ford20 Article No. 83-6-24SMOKE 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:
FIGURE 26:
2. With the engine at operating temperature and the transmission in neutral, rev the engine to about 1500 RPM momentarily, return to idle, and begin timing. If, after 150 seconds, the thermactor bypass valve dumps (vents) the thermactor air system is OK. If not, remove the vacuum delay valve (D8AE-9E897-BA) (Red and White color code, #40) and the in-line vacuum reservoir (D6TE- 9E453-AA), Figures 25 and 26.
3. Check the vacuum system to the thermactor
bypass valve for vacuum to insure no blockage.
4. Replace the vacuum delay valve with the same from service stock (D8AZ-9E487-B) and eliminate the inline vacuum reservoir with 7/32" vacuum hose (approximately 5.0") and a 1/4 x 1/4 connector (383005-S). Do not re-use the short vacuum hose.
5. Install a fuel vacuum separator assembly (D4FZ- 9C369-A) at the third port of the carburetor (Figure 25). Note the proper orientation.
6. With all steps above completed, re-test system once again to insure proper function of thermactor bypass valve.
PART NUMBER PART NAME CLASS
D8AZ-9E897-B Vacuum Delay Valve BM
D4FZ-9C369-A Fuel Vacuum Separator WG
383005-S 1/4 x 1/4 Connector RM
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: M
TIME: "Actual Time" as defined in the Warranty and Policy Manual. DLR. CODING: Basic Part No. 9E897 Code: 41