240sx, fuel, pump, relay

Troubleshooting 1995-98 S14 Fuel Pump/Relay Issues

This should help you diagnose fuel issues on your Nissan 240SX. Use at your own risk, and make sure you have a multimeter (along with other common tools) before attempting this.

Three main failure points:

  • Fuel Pump
  • Fuel Pump Relay
  • ECU

Fuel Pump Plug:

Few things you can check for here:

First check for 12V at the plug with key in the ON position, if you’re getting 12V -> fuel pump is likely bad;

Check for continuity between plug terminal B (the one with black wire going to it) and chassis;

Check for continuity between plug terminal A and Pin 5 on your Fuel Pump Relay;

240sx, fuel, pump, relay

Fuel Pump Relay Location (Driver Side Kick Panel):

You’ll see another blue and black relays next to it under driver side kick panel, it’s the one that has four black wires going to it;

Simple test you can do before taking out the relay, is to hold it in your hand and turn the key into ON position without starting the car – if they relay is good, you should feel it click;

240sx, fuel, pump, relay

Fuel Pump Relay Plug and Fuse:

Don’t forget to check your fuse if you haven’t already done so;

Pin #1 gets power from Ignition Switch, so you should see 12V with key in the ON position; 

Pin #2 is ground signal from ECU, it can be verified by checking for continuity between Pin #2 and a ground point while key is in the ON position (it will only work for couple seconds after turning the key);

Pin #3 is power source from battery. It is wired to your 15 AMP Fuel Pump Fuse;

Pin #5 supplies power to your fuel pump so it should have continuity to Pin A on your fuel pump plug;

240sx, fuel, pump, relay

Bench checking your relay:

Hook up Pin 1 and 2 to your battery (doesn’t matter which one goes to positive or negative);

Use your multimeter to check for continuity between Pin 3 and 5 – should have continuity with power applied;

240sx, fuel, pump, relay

Hope this helps!

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