Fuel pressure drops then stalls

Sho said:
Have you replaced the crank position sensor? I had an issue with my car last year where it'd die whenever it felt like it and then would just crank and only fire up when it wanted. Ended up being the crank position sensor and never threw any codes
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No. Any reason I should suspect it?
 
Yeh, I did a valve cleaning and injector seal install in March...finished everything up and the car would not attempt to crank at all. Wasted about four hours doing a full teardown to fuel rail and checking all connections, only to ultimately find that the issue was the crank sensor being misaligned after having hand-turned the crank during cleaning in order to close the valves for their B12 soak. Turned the crank a bit more until it was realigned and she started right up and has given me zero issues. Fun times.
 
My car would just shut off randomly as it got to temp. Whether it be at idle or cruising on the highway. Wouldn't restart unless I let it sit for a bit. Replaced crank sensor and has been fine ever since
 
You could try back probing the Crank sensor and monitoring voltage there if you have a DVOM, but catching the voltage drop or spike is difficult. Really the only other way to test the sensor is with an oscilloscope. Most Snap On or other high quality scanners have this feature but finding someone who knows how to use and decipher the readings is another problem entirely. L3K9-18-221A is the part number for the crank sensor. OEMPARTZ.COM has them for 50 bucks. If you Replace it, don't fuck up the position or your car will never run correctly. Count the teeth counter-clockwise back from the gap, or missing tooth when the crank is at TDC. 20 teeth back is correct. There is a hole in the harmonic balancer that lines up with a threaded hole in the timing cover and a M6x1.0 bolt threads into it.

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Fwiw my sentra would just die out of know where whether i was driving or idleing. As soon as i replaced my crank sensor it was good to go. If there are any metal shavings on the face of the sensor it will fuck it up as well. Just buy one from advance auto and return it if it dosent work.
 
New development. So, all those new parts and maybe I did or maybe I did not test jumping the fuel pump circuit relay again but we did today and car stays running. Coolant temps got up to 180 and the HPFP actual stayed right around the desired pressure. Thought it might have been the grounding on the new resistor. With KOEO, all the ports where both the fuel pump relay and circuit rlay should have power, have power. Of course, with the circuit jumped and the resistor removed, it also runs just fine. Still no codes. Ideas very much appreciated here.
 
I would suspect a bad resistor. I know you said that you replaced it, but was the replacement used?
 
The new resistor has continuity and the resistance is in range. That said, at the advice of another local, I'm going to jump the resistors plug with relays plugged in to see what happens.
 
We may have found the culprit. This us inside the fuse box. Mouse nest. From one of the resistors wires, I get continuity to both the battery post and the signal input post at the fuel pump relay. This seems wrong. The other wire only has continuity to the circuit relay at one post (forget which.) I also don't get a full 12v going into the resistor, which also seems wrong.
 

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Yup, that'll do it every time. Clean thoroughly and carefully inspect the wires for damage.
 
Going to spray down with bleach and ammonia then blast it out with the power washer.
[doublepost=1511283505][/doublepost]@Raider why am I still a Greenie?
 
Tommy said:
Going to spray down with bleach and ammonia then blast it out with the power washer.
[doublepost=1511283505][/doublepost]@Raider why am I still a Greenie?
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You need to donate to change color.

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Raider said:
You need to donate to change color.

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Done, Bisch!!@!
[doublepost=1511362535][/doublepost]Resistance test results show resistance on one side of the resistors plug to the relays. This is without the resistor inline.
 

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Resistance or open circuit? It is normal to see .2-.4 Ohms on a good circuit. Instead of tearing into the entire wiring harness, just run new wires from the fuse block to the Resistor and splice them accordingly.
[doublepost=1511384295][/doublepost]And of course, if the relay is not energized, you will show OL
 
Resistance. Seems high, especially since one wire shows no resistance at all.
 
Unless your car uses hyperconductors for wires, there will always be some measurable resistance. Like I said, just run new wires to the resistor from the relay position and call it a day. The wires are likely damaged from the mouse, and a partially chewed wire can show excessive resistance.
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[doublepost=1511389495][/doublepost]Correction: Superconductor. Hyperconductors are from StarTrek- we ain't got those yet
 
I can't tell you how good it felt to actually drive my car again. So, ran a new 14a wire from the 30a Fuel Pump fuse post to a T connector I attached to the red wire going into the fuel pump resistor. No loss at those same points anymore. Datalog attached.
This (all the repairs) also seems to have gotten rid of my random misfires in cylinder 1. Car sounds better than it has in 5 years now.
 

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