Engine - Hard Start/No Start
Article No. 85-9-13HARD/NO START - 2.3L HSC CFI
FORD 1985 TEMPO
LINCOLN-MERCURY 1985 TOPAZ
Hard start or no start drive concerns may be caused by low or no fuel pressure caused by an improperly operating electric fuel pump. The fuel pump should be checked using the following diagnostic procedure.
1. Check fuel tank for adequate fuel supply.
2. Check for fuel leakage at all fittings and lines.
3. Check for electrical continuity to fuel pump:
a. Locate inertia switch. The inertia switch is located in the luggage compartment.
b. Remove the electrical connector from the inertia switch and connect a continuity tester to one of the leads at the wiring harness.
Figure 12 - INERTIA SWITCH:
Figure 13 - FUEL PUMP, SENDER FLANGE VIEW:
c. Check for continuity between the wire and ground. If no continuity is detected, switch to the other wire and recheck for continuity. If continuity is not present at either lead, the fuel tank must be removed from the vehicle and continuity must be checked between the wiring harness and the switch leads. If the leads check OK, check continuity across the pump terminals (Fig. 13). If no continuity is present across terminals, then replace the fuel pump and sender assembly. If continuity is present across pump terminals, check the ground circuit or the connections to the pump from the body connector.
d. Reconnect the electrical connector to the inertia switch and attach a voltmeter to the wiring harness on the pump side of the switch (the side which showed continuity).
e. Turn on the ignition key while monitoring the voltage to the fuel pump.The meter should read 10 volts or more for one second and then return to zero.
f. If voltage is not as specified, check the inertia switch to assure that it is not open and then check the electrical circuit to find the fault.
4. Check electric fuel pump operation:
a. Disconnect electrical connector at inertia switch.
b. Crank vehicle for minimum of 15 seconds to reduce fuel pressure in lines.
c. Disconnect fuel return line at throttle body. Use care to avoid fuel spillage.
d. Connect hose from fuel return fitting to a calibrated container of at least one quart.
e. Disconnect the jumper hose between the throttle body and the fuel filter in the engine compartment.
CAUTION: The fuel system contains pressurized fuel after the vehicle is shut down and will maintain this pressure for a long period of time.
f. Attach a pressure gauge between the throttle body and the fuel filter.
Figure 10:
Figure 11 - Wiring Diagram:
g. Locate the fuel pump relay (behind the glove box) and remove and replace it with the modified relay (Fig. 10). The ground lead should be brought outside the vehicle and located nearby.
h. Energize the fuel pump (ground the ground lead from the relay) for 10 seconds. Observe pressure while energized. If there is no pressure, monitor the voltage past the inertia switch to determine whether the pump is gening the proper voltage. Correct any faults as necessary.
i. The fuel pump is operating properly if:
^ The fuel pump pressure reaches 90-110 kPa (13-16 psi) and:
^ The fuel flow is a minimum of 178 ml. (6 ounces) in ten seconds, and:
^ Fuel pressure remains at a minimum of 80 kPa (11.6 psi) immediately after shutdown.
j. If all three conditions are met, the fuel pump is operating properly. Check for engine and electrical problems.
k. If pressure condition is met, but flow is not, check for blocked filters and fuel supply lines. After correcting any blockages, recheck. If flow conditions are still not met, replace fuel pump sender assembly.
l. If both pressure and flow conditions are met, but pressure will not maintain after de-energization, check for leaking injectors or regulator. If both check OK, replace fuel pump-sender assembly.
m. If no flow or pressure is seen, the fuel system should be rechecked as in step k. If no trouble is found, remove the fuel tank and replace the fuel pump-sender assembly.
n. After the procedure is complete, replace the modified fuel pump relay with the original relay.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: 9350BE
TIME: 0.5 Hr. DLR. CODING: Basic Part No. 9350 - Code 09