E 100 Van V8-302 5.0L (1983)
Fuel Pressure Regulator: Customer Interest
Engine - Hard Starting/Long Crank Times
Article No. 85-16-21
HARD START - LONG CRANK TIMES (5.0L EFI)
LIGHT TRUCK F-SERIES, BRONCO
Long crank time and/or hard start with a cold or hot engine may be the result of a leaking fuel pressure regulator. The leak (internal) lets the pressure
leak down at the fuel rail. This causes a no fuel or starvation until the pressure is built up again.
Perform the following to alleviate this concern.
NOTE:
Prior to any repair:
Run the engine several minutes and shut down.
Rough/unstable idle with a lower than normal vacuum may indicate stuck/leaky injectors which would contribute to a loss in system pressure.
Check the fuel system for external leaks - lines, connections at the filter, fuel rails, pressure regulator and injectors. Repair as necessary.
If no leaks are present:
Turn the ignition switch to "On" position and hold for two seconds. DO NOT CRANK ENGINE. Repeat ten times. If
engine now starts normally, it indicates a fuel system pressure leak down/loss. Continue with the following procedure. If
it doesn't start, then the problem is not pressure regulator related. Refer to engine diagnostic procedure.
1.
Relieve pressure in fuel rail per Section 24-50-28, 1985 Light Truck Shop Manual, Volume B.
2.
Remove the fuel pressure regulator.
3.
Inspect the gasket and O-ring for cracks and cuts, replace as required.
4.
Connect the vacuum gauge to the fuel return tube (7/32-inch diameter tube centered on baseplate).
5.
Apply 20 inches Hg. of vacuum.
6.
Vacuum must not drop below 10 inches Hg. in 10 seconds.
If vacuum check does not drop below 10 inches Hg. in 10 seconds, the valve seat is good. Reassemble the regulator to the fuel manifold rail and check
the fuel pump for a leaky check valve.
If the vacuum indicates a leaky valve seat in the pressure regulator, replace the regulator.
PART NUMBER
PART NAME
CLASS
E3FZ-9C968-A
Fuel Pressure Regulator
R
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9968B85
TIME:
1.1 Hrs. DLR. CODING: Basic Part No. 9C968 - Code: N3