Sudden power/fuel cut off at highway cruising
 

Hi, I have a 2006 g35 coupe at around 130k. Recently, It starts to behave unexpectedly. I was cruising on highway at around 65mph, it suddenly feel like the car lost all power, it dit not shutdown and pressing on the gas pedal does not do anything. I was able to pull over and restart the engine. There is no SEL on the dash and it started smoothly. After restart, it worked fine.

It had similar symptoms a few days later. But this time, it only last for a little while and lost power again. I searched through a lot of posts here, looks like there could be multiple possible causes. I am guessing something related to fuel line, such as failing fuel pump, clogged fuel injectors. Here are my thoughts:
- it happens only when low at fuel, around 1/4 tank, when I fill it up, there is no issue. This looks like a failing fuel pump.
- there is no SEL on dash and the engine does not completely shut down.
- the loss of power happened when I tried a hard acceleration and feel like the engine is starve of fuel. It felt like losing power for a second and then come back on the next second

Guys, what's your thoughts on this issue? Really could use some help here, thanks so much!

I would start with making sure your gas gauge is accurate. It could be less than it actually is and then I would check your fuel pressure next under load.

My gas gauge seems to be accurate for the last few fill-ups. What's the easy way to check fuel pressure under load, tools?
Right now the car runs, but I can feel drag all the time and significant lower torque when trying to accelerate.

Well, for the G it kind of sucks to check the fuel pressure. You can buy an adapter from Z1 for about 60 bucks I think that tees in between the damper and fuel rail. You'd then hook up a gauge to the adapter and read the pressure at idle, hitting the gas, etc..

You might be able to take some current/voltage measurements of the pump at the connector, but using a fuel pressure gauge is easier to understand.