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LISTEN_180SX

180SX fuel pump not priming

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My 180SX won't start (was starting/running fine only a few days ago). It has a HKS fuel pump in it that is probably 4-5 years old now.

 

I can't hear the fuel pump priming anymore; and have pulled the hose off the FPR and confirmed that no fuel is flowing when the car is cranking over. I've checked the 15A fuse in the engine bay and it is ok - do I need to check/replace the "EGI PUMP" relay too?

 

Without a spare pump to test with, what else can I do to work out if it is wiring/electrical related, or the pump itself?

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pull the relay out and bridge the contacts. crank it and see it it starts

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Thanks mate. It's a 4-pin relay, so which contacts do i need to bridge? I don't want to fk anything up..

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Check the relay and fuse. Check voltage at the pump wiring, it should be 13.6-14v.

Run power directly to the pump and see if it pumps.

If all else fails I have a gtr pump not being used if you need a cheap fix.

 

 

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As above. Ensure there is power at the pump either when someone is cranking, or when u first turn the key one there will be power for 3 seconds. If there is and its still not priming trying earthing the negative wire from the pump to the chassis ground.

If still no good need a new pump

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Ok, tried a few things; here are the results:

 

Checking for power at the pump, there was no power at the positive cable (white with purple stripe); however the solid yellow and the yellow/green wires had power - even when not cranking. The fuse in the engine bay is not blown, and I swapped the relay's around, and still no power at the white/purple wire when cranking or when 'reds' are on.

 

I ran a solid positive cable from the battery to the white/purple wire at the pump and the pump starting pumping - fuel flowed out of the overflow at the rail (so that eliminates the pump being dead - yay!). I tried to start the car with the solid power cable pushed into the pump plug but the car still wouldn't start. It is possible I flooded it though, so that could be the reason why it didn't start.

 

However, why is there no power at the fuel pump if the fuses and relays are ok? The only thing I didn't do is make a new earth for the pump to the chassis - could that resolve the no power at the pump issue?

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exact same, as in no power at the pump, yet fuel pump pumps when giving direct power?

done all the same checks to make sure fuse and pump relays are ok?

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is there 12V from the ignition switch (or possibly 5V from the ECU-cant remember how these are wired) on the relay trigger wire when you turn the ignition to ON? Also an earth signal on the relay wires? If not then the connection from relay to the ignition/ECU is bad.

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