Engine - Spark Knock/Hesitation/Surge/Stumble

86ford20

Article No. 86-7-16


SPARK KNOCK, HESITATION, SURGE, STUMBLE, POOR FUEL ECONOMY (5.0L EFI)

LIGHT TRUCK 1985-86 E, F SERIES, BRONCO

Detonation (spark knock), hesitation, surge, stumble or poor fuel economy, may be caused by leaking or damaged vacuum lines.

If the engine vacuum harness (-9E498-) contacts hot EGR tube or exhaust manifold, the above drive concerns can result.

Figure 10:

1. Visually inspect vacuum harness for improper routing and/or heat damage (i.e., burned or melted nylon tubing). See Figure 10.

2. If damage is evident, repair or replace vacuum tubing as necessary.

3. Assure vacuum harness is routed away from EGR tube and R.H. exhaust manifold. The vacuum harness (-9E498-) can be routed and secured by use of bundling strap, part number 95874-S or equivalent. See Figure 10.
PART NUMBER PART NAME CLASS

95874-S Bundling Strap AG


OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9498A86
TIME: 0.5 Hr. - F Series and Bronco 0.6 Hr. - E Series DLR. CODING: Basic Part No. 9E498 - Code: M7