97 pathfinder cranks won't start

[Lesa59]

so a couple of weeks ago when the weather began heating up, on occasion the car would die at idle after driving ~20 miles or so but would start right back up. Didn't happen often, thought it was vapor locking so had gas cap checked twice - fine.
As the days went on it began happening with great frequency and even while driving - rpm would drop to 0 and it'd die but start back up.
Yesterday on an 80 mile trip, about 1/2 way into it at highway speeds it began dying about every mile but would start back up - after 20 times of this it finally died and now won't start at all despite a strong crank.
So here's what's been done:
new distributor
new plugs and wires (both, as it turns out, needed replacing)
checked for blown head gasket - fine
Checked for spark and fuel - fine
disconnected the security system, made no difference so reconnected.
checked for jumped / broken timing belt - fine

The only thing I can think of left to do is replace the crank shaft sensor - as it's a major PIA, I'm hoping someone has some other ideas here. I've read through the forum and see this is not an uncommon problem with this vehicle but the solutions that were offered have already been covered so I'm rather at a loss.

97 Pathfinder
4WD
manual
6 cyl

[Lesa59]

If it's of importance - I went through this same thing with this same car 2 years ago - it ended up being the distributor and while I felt it unlikely it would go bad in such a short period of time all things given, I replaced it first this time - made no difference.
The fuel pump was replaced last go round even though there was nothing wrong with the one that was in it. You can hear the fuel pump doing it's thing when you turn the key into the on position so it appears to be operating properly and I am getting gas to the plugs.

[MisterH]

Seems like you've covered all the basics however you never mentioned whether or not you've been getting any SES lights or have used a scan tool in your diagnostic steps. If the intermittent failures have occurred over a long period what you ideally want to do is use a scan tool to monitor and record what is actually happening. Also, when you've verified the presence of spark and adequate fuel distribution it usually means a primary sensor has failed or is electrically unstable. These usually trigger a SES light but not always. Has the IAC ever been replaced?

[Rockwood]

Try giving it a good shot of starting fluid. If it starts, that confirms spark, and then it is probably a fuel problem of some kind.

[Lesa59]

A scanner was put on it a few weeks back and it was throwing codes for the O2 sensors, but fact is it's been throwing those codes forever, even after the O2 sensors were replaced 2 years ago....still got code, so we tend to ignore that.
If ICS stands for ignition control sensor, no that has not been changed and last checked it didn't throw code for it, but that's not to say it isn't an issue now (I'm 17 miles from the nearest town and don't have ready access to a code reader), but would that have caused it to die as it did - it still started up....everything but the last that is!

This morning we double checked that the timing was correct and it is spot on, also checked compression and it is present and fine, getting plenty of spark and plenty of gas.....
I'm at a complete loss at this point.
It did show a flash of life twice this morning but it was short lived, and on saturday it actually turned over, it was flooded so I kept the gas peddle to the floor but let off it too soon, it died and here we are....still.

[Lesa59]

Seems like you've covered all the basics however you never mentioned whether or not you've been getting any SES lights or have used a scan tool in your diagnostic steps. If the intermittent failures have occurred over a long period what you ideally want to do is use a scan tool to monitor and record what is actually happening. Also, when you've verified the presence of spark and adequate fuel distribution it usually means a primary sensor has failed or is electrically unstable. These usually trigger a SES light but not always. Has the IAC ever been replaced?

refresh me, what is an IAC

[Lesa59]

Doing some more research I came across another (2 actually) who experienced the same issue - car began dying once temperatures (environment) got hot. It was suggested that the "main relay" had finally given out and should be replaced - so I replaced it to no avail.
any chance this is as simple as the starter relay or another reply that I'm not picking up on

[Lesa59]

Well, just don't know what to make of any of this -
Disconnected the security system as I read where they can sometimes cause these issues if they've gone wanky, only resulted in the car not even cranking (good to know it's working!), determined that the battery was pretty much shot so replaced that, unfortunately having the battery out for an hour for the drive into town to replace it means no codes as they all cleared.

Looking into the cats today and possibly the ignition electronics but not holding out much hope at this point, 8 days of this is about the limits of my tolerance for BS car problems.....there's a SAR group here that scours the state looking for pathfinders for their rock climbing SAR needs as they are the prefered vehicle of all of them and they pay top dollar running or not as they replace the motor and transmission regardless (their interest is in the body / frame design), so it looks like my pathfinder is going to be sold for more money than it will bring on the civilian market and replaced with something that hopefully doesn't have over 900 instances of this same and seemingly impossible to pin point issue from those with the same year and model truck on nissian forums everywhere.....

[Lesa59]

BTW, did put a compression tester on it - perfectly fine. In fact everything that's been tested so far is perfectly fine.
Good luck to other 97 owners! I love this truck, have had it for 6 years and it was one of the most reliable, strongest running vehicles I've purchased in many years, but this particular issue is one that you will see repeated in forum and after forum - same report, never any clear answers as to cause and root of the problem never seems to be the same thing or one that can be pinpointed - just a matter or replacing thing after thing until you hit on the one thing that was the issue with your particular car, and don't expect much help from codes - the only codes I was getting prior to pulling the battery was 02 sensors and that was only due to having not cleared the code after replacing them prior to this issue.

[Rockwood]

Did you try starting fluid? Starting fluid will help get the engine started when it is flooded. You can keep giving the engine small squirts in the intake for 20 seconds or so to keep it running and burn off excess fuel. Run it at 1500 rpm for a minute or two, then see if it will idle.

[nico911411]

If it finally started after long crank, it is probably FUEL DAMPER or FUEL REGULATOR. if you remove the VACUUM HOSES from these and there's fuel leaking out, the car should start and run normally.