fuel pump

[nissan720]

is there any way to detect a bad electric fuel pump?my guage is bouncing between 3 and 3.5. i hear the pump when i first switch on the truck.

[datzenmike]

Sounds ok to me. This is the normal range of pressure for a stock Nissan pump. 

 

Same with oil pressure gauges. Idle can be 50 PSI when cold but 30 when hot and anywhere in between when running at low speeds. Seeing this you might think something is wrong when everything is normal and why few vehicles have them and only have a low pressure warning light. Most cars drivers haven't a clue what is normal, so best to not have a pressure gauge and upset them OR one that is weighted with a sluggish response so there are no sudden 'alarming' changes. Ignorance is bliss.

[Stoffregen Motorsports]

I installed a fuel pressure regulator and gauge on a customer's truck a few years back and he cannot leave the dam thing alone. He says the gauge sweeps all over the place and he keeps messing with the fuel pressure. I finally got my hand on it and re-set the fuel pressure and told him essentially what you (Mike) just said. If it didn't have a gauge, you wouldn't be worrying about the fuel pressure, so leave it alone!

 

There is such a thing as a PSI snubber which helps maintain a more constant PSI. You can get them on Amazon - https://www.amazon.com/Auto-Meter-3279-Pressure-Snubber/dp/B001O0BN6K

 

Note - that snubber is for diesel with over 30 psi.

Edited August 14, 2020 by Stoffregen Motorsports

[datzenmike]

Back in the muscle car days everyone wanted gauges and not ''idiot lights'. So the big 3 obliged with gauges..... without any numbers, just a normal run range. Go figure.

[john510]

16 hours ago, nissan720 said:

is there any way to detect a bad electric fuel pump?my guage is bouncing between 3 and 3.5. i hear the pump when i first switch on the truck.

Buy an oil filled gauge.The needle won't jump around.I would think if it's staying between 3 and 3.5 your fine.

[nissan720]

yeah its between 3 and 3.5