# 99 Sentra 1.6L Won't Start - Fuel?



## jamesm113 (Jun 20, 2010)

99 Sentra GXE (1.6L) with 160k miles.

Car was running great, then driving home on freeway, and car started losing power. I started pulling over, and then got a surge of power, but by the time I got to the shoulder, the car stalled completely and would not start again.

Had the car towed home and it still will not start.

Got a fuel pressure test kit from O'Reilly's. After turning the key to on, the gauge was measuring about 42psi, but dropping immediately to around 20psi (within 5 seconds).

Am I barking up the right tree? What is the pressure supposed to be when just turning the ign switch to ON? Thinking I will check the fuel lines for leaks tomorrow.

Thanks


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## smj999smj (Jan 1, 2006)

The 42psi is fine, but it should hold the pressure. Once it starts running, the pressure should drop as the regulator holds it to around 34-36psi. First, pinch-off the fuel hose between the fuel gauge and the fuel rail; the pressure should stay at 42psi. If it doesn't, then check for leaks and if there are no leaks, the pump is faulty. If all is good, un-pinch the fuel hose and go to the next step.
Pinch-off the fuel return hose and retest. Again, the fuel pressure should stay at 42psi. If it does, the fuel pressure regulator is faulty. If it doesn't, then you have one or more fuel injectors leaking down.


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## jamesm113 (Jun 20, 2010)

Well, went to re-test and now the gauge is reading zero.

I did a voltage test at the fuel pump connector and found 11.9V. Also still hear the fuel pump whirring. The car has a gal or two short of a fuel tank of gas.


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## smj999smj (Jan 1, 2006)

If you pinch-off the line off after the fuel pressure tester, but before the fuel rail, and it's still zero, then either the fuel line inside the tank fell off or the pump is shot...or, you have something else inside your tank besides gas and it has clogged the sock. You'll have to pull the fuel sending unit out to find out which. They always seem to fail when the tank is full!


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## jamesm113 (Jun 20, 2010)

Replaced the fuel pump. Still reading 0PSI, even if I pinch the fuel line right after the T with linemen's pliers.

As a test (to make sure the pump was operating and I didn't mix up the fuel lines anywhere), I pulled the return line above the gas tank and turned the ign switch to on. A steady stream flowed out of the return line. So some fuel is getting to the front of the car and back, but just not enough pressure.

Out of ideas for now..


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## smj999smj (Jan 1, 2006)

Maybe you got a bad "new" pump? Possible clogged fuel filter or clogged fuel line?


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## jamesm113 (Jun 20, 2010)

smj999smj said:


> Maybe you got a bad "new" pump? Possible clogged fuel filter or clogged fuel line?


I replaced the fuel filter as a troubleshooting step. It's an OEM from the local nissan dealer.

The new pump was a brand new Bosch delivered from Amazon.

Looking into a clogged fuel line. Any good tests to find this out? I could tap the fuel pressure gauge right after the fuel pump to see. hmmm..


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## jamesm113 (Jun 20, 2010)

Ok, did some more tests tonight.

1. Attached fuel pressure gauge right after fuel sending unit. 0psi

2. Attached fuel pressure gauge right after fuel pump. 0PSI

3. attached fuel pressure gauge right after fuel pump. Attached hose clamp to line right after fuel pressure gauge's T. Saw fuel spray out all over at the pump's output barb/hose connection. Think that's my issue? Need to replace the hose and clamps?


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## smj999smj (Jan 1, 2006)

Yeah, if you are pinching off the fuel hose and the pump is running and pushing gas out between the pump and the pinch-off point, that's where you're losing your pressure. Make sure you use fuel-injection clamps and fuel-injection hose, not regular fuel hose and fuel clamps.


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## jamesm113 (Jun 20, 2010)

Ok new hose and clamps installed. Read 0psi at first, but the pump built up pressure to 30-40psi after a few ign on/off cycles. Seems to drop approx 5psi over 5 minutes.

Car still won't start. Think I will verify there is spark/test compression tomorrow.


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## jamesm113 (Jun 20, 2010)

Ignition rotor screw had fallen off. Car started right up after I re-attached it. Running better than ever.

Thanks for your help


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## Jopet (Aug 10, 2009)

Next thing to check if you have chain noise is the upper tesioner. My rotor kept falling off until I fixed my timing chains


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