Fuel pump fuse location

When the fuel pump is working, the carburettor float would stop the flow of fuel into the carb when the fuel level is attained. When pressure builds up, the pump piston would be held in the pressurised position and that would not allow the contact points inside the pump to meet and that would cut the current flow and stopp the fuel pump from working.

Keeping the fuel pump running would not flood the carb unless the float or needle valve is faulty.

In cases of accidents, if the engine had stalled and the fuel pump is running with a ruptured fuel line, fuel would continue to be pumped out and spews out of the ruptured hose, that would be a safety hazard.

The fuel pump (main ) relay is located underdash just above the fuse box. It is a 7 pin grey box with brown socket points.

Problem resolved?

Your carb should stop the fuel from overflowing like KH said, if not your needle and seat or float is out of adjustemnt. Also the pump you have may have to much pressufe for your system. A carb type engine on ly uses 7psi MAX. So you woul dneed to add a regulator for it or disconnect the fuse you have going to teh relay so thepump won't run while you tinker with your electrical problem.

Hi nando39,

Thank you for the donation.

The fuel pump wiring is not connected when engine is not running and any wire shorting should not cause it to malfunction.

However a shorting of the ECU would cause the fuel pump not to work.

If the fuel pump does not work with voltage applied, then it is either bad or the wire circuit is open. I wuld suggest using a remote wire to test the fuel pump operations.

Did you check all the fuses? Another might be fused too.
Is the CEL showing for 2 seconds when ignition switch is turned ON?

Hi nando39,

CEL = Check Engine Lamp.

Are there any sparks at the plugs? If yes, then you need to check the fuel circuit. The PGM-FI main relay might be intermittently failing resulting in no power supply to the fuel pump.

Test for power output to fuel pump for 2 seconds when igniton switch is turned ON.

Hi nando39,

I am not sure which WHITE wire you are refering to as the power supply from the PGM-FI main relay to fuel pump should be Black/Yellow.

If the white wire is rather larger in diameter, then it should be power supply from the underhood fuse box which leads to the ignition switch. If that is the case, I believe one of the fuse is blown.

I would suggest checking
Underhood fuse box
1. Fuse # 46 (15 A )
2. Fuse # 42 ( 50 A )
Underdash
3. Fuse # 13 ( 7.5 A )

I would advise against shorting or applying voltage to the ECM without understanding the wiring system first.

Most likely caused by faulty wiring. Check harness connection at both the pump as well as the fuse box, ensure it is plugged in correctly and no damaged wiring.

Hi nando39,

No, the 50 A fuse is under hood Fuse # 42. Guess that is not the cause as it is the main power supply to the ignition switch.

From the connector can you please tell me the pin # location. I seem to have different wire colors for my diagrams.

I will do some research and see if I can pinpoint the cause.

Ok, I now understand which 2 wires you are refering to.
1. A10 = interior light circuit
2. C4 = Reverse light going to the gear shift.

From the circuit, there should be no connection to the fuse. From where did you tap the battery voltage to initially blow the fuse? What is the fuse location that blows initially?

Hi nando39,

I suggest we go back to the basics to understand what is happening. I would like you to provide me with some information with the following tests before we continue further.

1. Attach a test lamp to distributor Black/Yellow and turn ignition switch to ON. Battery voltage must be available.
If not, check Fuse # 1. If ok, test ignition switch black Yellow wire for voltage, must have voltage, if not switch is faulty.
If above ok, crank the engine. Voltage must be available. If not, ignition switch is faulty.
Sparks must be available at the plugs. If not, either distributor is fasulty or PCM grounding is inappropriate or PCM is faulty.

2. Attach a test lamp to PGM-FI main relay terminal # 2, ( Blue/Orange wire) Lamp must light up while cranking. If not, check fuse # 13 ( 7.5 A )

3. With ignition switch turned ON and while cranking, battery voltage must be present at terminal # 4.

4. Attach test lamp to PGM-FI relay terminal. Turn ignition switch ON. Lamp must light up for 2 seconds.
Item 1, 2 and 3 above must be ok before this test needs to be done. If no power supply, relay is faulty.