2003 R50 engine die, then resume every 3 seconds

[Micallen]

or so leaving work today. I kept steady gas pedal pressure during this. Happened about 10 times (in 30-40 seconds) then back to normal. It had never done this before. I was alarmed, but kept driving. No CEL. Then, about 2 minutes later, it just started dying. The motor died, and I coasted to a stop. It would not re-crank. Turns over, but wont fire. Sounds like it has 2 or 3 times before when the crankshaft pos sensor died and had to be replaced. BUT, I have no idea what caused the first part. Any ideas?

I bought a new crankshaft position sensor and will replace tomorrow. Hope this one lasts more than 1 year.

[VStar650CL]

That does sound like dying-sensor behavior. When a CKP starts cutting out the ECM goes, "Duh," trying to correlate the still-working cam sensors with the dead CKP. Of course it can't, so the effect is go-stop-go-stop-go-stop. Was your replacement sensor OE or parts store? The latter are not recommended. I can't tell you how much hair I've seen people pull out over the years because of China-cheap inductive and Hall sensors. When they get to my bay, it's always the same conversation:
"But it's a brand new sensor..."
"Yessir, but it's a s#%* new sensor."

[Micallen]

That does sound like dying-sensor behavior. When a CKP starts cutting out the ECM goes, "Duh," trying to correlate the still-working cam sensors with the dead CKP. Of course it can't, so the effect is go-stop-go-stop-go-stop. Was your replacement sensor OE or parts store? The latter are not recommended. I can't tell you how much hair I've seen people pull out over the years because of China-cheap inductive and Hall sensors. When they get to my bay, it's always the same conversation:
"But it's a brand new sensor..."
"Yessir, but it's a s#%* new sensor."

LOL. I asked the guy at Advance why I'm having to replace every year. He said that's about how long they are designed to last.

If it is indeed the crank PS, I will go buy a Nissan CPS and leave it in the car for next year.

[Micallen]

Is 23731-AL60D the correct Nissan part # for the crankshaft P.S.?

[VStar650CL]

Visit NissanPartsDeal.com and plug in your VIN. Their diagrams and dbase come straight from Nissan DPC, so you'll get the right part number every time.

[Mike W.]

Interesting thread. I'm not very knowledgeable on Nissans, but in the BMW world I mostly live in, it's the same thing. Certain parts you can go aftermarket, but especially Cam/Crank sensors, BMW is emphatically the way to go. Some say OEM, the original manufacturer of that very part is ok, but there's some thought even those are almost or sometimes seconds of what BMW branded will be.

Doesn't seem like it would be that sophisticated a device, it's basically an on/off switch. But apparently it is.

[VStar650CL]

It's not an on-off switch, although the output is just an N-FET or N-transistor operating as an open-collector. The chips for Hall Effect devices are actually quite sophisticated. They're also magnetically "tuned", which is why simply dropping one on the floor can destroy it. Here's a datasheet for the sort of linear Hall sensor typically used for automotive applications:

https://www.ti.com/lit/ds/symlink/tmag5 ... r.com%252F

[Micallen]

I did order a genuine Nissan part, just haven't had time to install yet. I will install it, and keep the aftermarket in the car as a backup. But HOPEFULLY won't need it!