While driving 60mph+, the car suddenly starts to slow down and im trying to press the gas but it wouldn’t do anything ( like if the gas tank is empty). I quickly steer it on the side of road and try to start it. I will crank but will not start! This issue has happened in the past going the same speed but usually I’m able to get the car running after a few minutes. This time it took hours and crank timing disabled multiple times and yet no start. Car gets towed home, I replace the fuel pressure sensor and yet car doesn’t start. I spray starting fluid into my intake and the car gets running for a couple of seconds! Is this a fuel pump issue?
. 2015 mustang ecoboost
You’ve proved it’s definitely a fuel pressure/delivery issue
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The problem might be with a bad crankshaft position sensor.
If the computer doesn’t see a signal from this sensor while engine is cranked over, the computer isn’t gong to run the fuel pump.
Tester
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Before replacing the fuel pump I suggest you first make sure that the pump is getting power to it. If that is good and the fuel pressure is low then replacing the pump seems to be the next step. Also check the fuel filter for any issues.
Okay I bought another fuel pump and crank shaft sensor from eBay. Let’s see if this fix’s the issue
Did u check fuel pressure?
Not sure how to test on this car
Just curious, what do you mean by that?
Use a FP tester. Autozone lets u use them. Going to change FP but won’t check pressure first? Sounds like something is preventing FP from running
Well I could check the fuel pressure. But as far as fuel issue goes, there could only be 2 issues. High pressure fuel pump or the in tank fuel pump. Based on my knowledge, it’s likely the intank fuel pump. I’ve noticed that when I’m pushing the engine to it’s limits for datalogging for my tuner, he has told me that there is a fuel issue during the shift at high rpms. Sometimes when I redline it, the power cuts off and goes into limp mode. It’s likely the fuel pump gas gone bad and can’t keep up…
Seems reasonable. I’ll note that your tuner should be doing more than just saying “there’s a fuel issue.” He should be figuring out what that fuel issue is and fixing it. Gofast cars aren’t much good if fuel issues make their top speed 0mph. 
So how modified IS this Mustang, Mike? And what year is it? What engine is it? Two fuel pumps is not the norm unless the fuel system has been modified or this is a direct injection engine. Seems there is a LOT of information missing for us to help you fix this problem.
Modified engines require more fuel volume. If the pump(s) can’t keep up, you get a lean condition that can burn holes in the pistons.
Noooo, could be bad wiring, bad grounds, janky impact sensor, worn fuel pump relays. If you are assuming these are all just fine, you should mention that, too.
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The engine isn’t that modified… near stock actually. It’s a 2015 mustang ecoboost; little 4 cylinder. It has 1700 cc injectors, new spark plugs, new coil packs, intercooler, bov, and a intake.
yeah, please explain this one.
I think the fact that the car shut off at 60mph+ is a fuel pump issue…
How much boost over stock? More boost means more fuel. If you are using stock pumps, as I already posted, you may not have enough pumps to provide the needed fuel volume and pressure.
Replacing both pumps is going to run over $350 for parts alone. If they are stock replacement pumps and your problem is inadequate flow, you have spent a lot of money to solve nothing.
I think maybe you should take this into a performance shop to diagnose and fix the problem.
Does this vehicle have direct injection?
If so, there would be a low pressure pump in the tank, and also a high pressure pump, which would be mounted on/near the engine
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Yes, it is direct injection, yes it does have 2 pumps. Low pressure pump and a high pressure pump. Each costs $165 from RockAuto
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The low pressure fuel pump is the one in the tank right?
Hear this^
That’s from the intank pump… does that sound right?
Yes, it is
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