Engine - Runs Rough After Extended Idling

87ford15

LOADING - 4.9L - AFTER EXTENDED IDLE OR Article No.
HOT START 87-18-21


LIGHT TRUCK: 1984-86 E SERIES, F SERIES, BRONCO

This article is being republished in its entirety to instruct dealership technicians that a new fuel line will have to be installed along with the new higher pressure fuel pump.


ISSUE: A rough-running engine after an extended idle or a hot restart in ambient temperatures above 80~F (27~C) may be caused by fuel vapor build-up in the carburetor fuel bowl. The electric bowl vent solenoid is closed when the engine is running and will not vent the fuel vapors. This condition could also be caused by fuel percolation in the fuel line.

ACTION: To correct this, install a vacuum bowl vent solenoid operated by the EGR port of the carburetor. This solenoid will vent the carburetor fuel bowl at engine idle. If the condition still exists, it will be necessary to install a highpressure fuel pump and new fuel line. Refer to the following service procedure.

1. Remove electric bowl vent solenoid and install new vacuum bowl vent solenoid, (E3TZ-9G332- A). The solenoid is located in the SHED line at the front of the carburetor.

2. Install a 3/16 inch tee connector (383013-S) in the vacuum line from the EGR port of carburetor. Connect a 5/32 inch I.D. vacuum hose between this tee and vacuum bowl vent solenoid.

3. If vacuum bowl vent solenoid does not correct this condition, the fuel may be percolating in the line. Install a new, higher-pressure fuel pump (E5TZ-9350-B) and new fuel line (E4TZ- 9B273-A). A new fuel line is required because the "stack" on the new fuel pump is one inch lower than the original pump.

PART NUMBER PART NAME CLASS

E4TZ-9B273-A Fuel Line CG
E3TZ-9G332-A Bowl Vent Solenoid BM
E5TZ-9350-B Fuel Pump B
383013-S Tee B

OTHER APPLICABLE ARTICLES: Supersedes 87-3-21
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION: SP871821A - Replace bowl vent solenoid
TIME: 0.4 Hr. - F Series, Bronco 0.6 Hr. - Econoline

OPERATION: SP87182B - Replace bowl vent solenoid, fuel pump and fuel line
TIME: 1.0 Hr. - F Series, Bronco 1.2 Hrs. - Econoline DLR. CODING: Basic Part No. DRIVE - Code: L4