Don't wanna sell my '03 but these gremlins...
 

Difficult to describe its problems and history without going on too long but I'll try. (It's an '03 GLE)

Issues began about two years ago when driving home from work, halfway up the hill it stalled and shut off. It sat in the driveway a few months as I intermittently attempted different things to get her to crank again. I started by isolating the missing component, which I presumed to be fuel delivery--spray a can of starter fluid in the intake and it would turn over, then peter out within five seconds. I changed the spark plugs and all three crank and cam sensors. Eventually I replaced the fuel pump and assembly and when this didn't solve it I threw it at a mechanic.

The mechanic replaced my fuel pump because the one I put in was cheap-o parts (lesson learned). She ran for a few months seemingly fixed. Then on cold starts it began to show a little reluctance, but it would always turn over eventually. Then it would to stumble on the highway at operating temp, every once in a while, then over the weeks the stumbles became lurches that made my heart jump and came on more often. Then as more weeks passed it began to occasionally stall out when I'd come to idle at a stop light, but I could still put it in park, shut it off and start it back up. More weeks passed and those restarts began to take longer as it got more reluctant. Finally one day, five minutes from a jobsite, it stalled in a blind curve and would not turn over. Had it towed to the dealership. I figured I'm tapped out, if they can't figure this out no one can.

They replace the cam and crank sensors again. They say fuel pressure is at about 7psi so they replace the fuel pump and filter. Again. Had to get help to pay the bill but it drove off the lot without any problem.

Fast forward three months to X-Mas Eve, driving home for holiday stuff, it unexpectedly starts to weaken on a backroad. The engine is unresponsive to the accelerator. Its misfiring and puttering and trying to stall so I turn off to an avenue where it goes for a few hundred yards before stalling and shutting off completely. Then its crank-no-start again. Get it towed back home and it starts again in the driveway. Tow guy said the security was chirping the whole way home. I'm not seeing the red light when I'm cranking so I dismiss NATS.

So on level surface it idled for about ten minutes, with some stumbling, then stalled at about operating temp. It still cranked when I removed the MAF (but only on level ground). Sometimes I can drive it a few miles, but definitely weakly, and inevitably it shuts off entirely. When its parked facing uphill it will not start. If facing downhill, it cranks and starts with hesitation. However as of yesterday afternoon its a solid crank-no-start situation.

I'm convinced there's a fuel delivery or air mixture issue and seeing as the fuel pump and crank and cam sensors are dealership installed, I don't think they're the culprit. Visual inspection I see the air intake boot past the MAF had a gash, I wrapped half a roll of electrical tape around it. Still crank no start. Today I'm getting MAF sensor cleaner and I'm gonna try that, but I don't expect positive result. Past all these repairs, I don't know where to go with it.

I did a manual diagnostic and I'm only getting two codes: P0102 (Mass Air Flow Sensor Circuit Low Input) and P0113 (Intake Air Temperature Sensor Circuit High Input). I reckon these were tripped when I temporarily removed the MAF sensor for testing. I'm gonna go check for shorts in the harness w/ the voltmeter and report back soon.

For all the head-banging this car has caused me I still love it and I want to save it, however I've got a Craigslist ad prepared to go with the addendum that the buyer is facing gremlins that even the dealership couldn't find. Right now I have a voltmeter in my toolbelt and I've got a bluetooth ODB-II tool coming in the mail. If anyone has suggestions I'm open and stubborn enought to try anything. :banghead:

tl;dr: Complicated crank-no-start. Half a tank of fuel. Battery connections are clean and tight and showing proper voltage. Fuel pump, filter, pressure regulator, cam and crank sensors, are all new. Patched a hole in the air intake boot. Not getting the red light from NATS on crank. MAF is suspicious and I've yet to clean it but I don't expect a result because with or without it it still won't start.

Today I added oil (a bit low), checked every fuse with my new light tester (all good), checked the voltage at the MAF sensor and cleaned it with the proper cleaner (good), checked the fuel pump relay (working), and checked the ignition switch system over from battery to ground (good). Everything checks out so far. Still shaking my head.

Sprayed starter fluid in and it cranked but died soon after. Its parked on an incline so I'm gonna level it out into my neighbor's driveway when it stops raining and see if it cranks.

'or air mixture issue and seeing as the fuel pump and crank and cam sensors are dealership installed, I don't think they're the culprit. Visual inspection I see the air intake boot past the MAF had a gash,"

You may have a few porblems. Looking for ONE problem is probably why your going in circles. As i quoted you above . Electrical tape will not fix that. unmetered air coming in even a little ,intermittent can cause problems like your describing. Fix that problem RIGHT.

Replace your IATS - not only is your car telling you that there is a problem, but perhaps more important, the symptoms match perfectly!
Also, I see no reason why MAF removal should trigger P0113. So, your IATS is bad. Only $30, here: https://www.rockauto.com/en/catalog/nissan,2003,maxima,3.5l+v6,1431954,heat+&+air+cond itioning,ambient+air+temperature+sensor,7000

This leaves the MAF. You should have cleaned it by now. If problems persist, replace it. Hitachi only, here: https://www.rockauto.com/en/catalog/nissan,2003,maxima,3.5l+v6,1431954,exhaust+&+emiss ion,mass+air+flow+sensor,5128 .... see if you can get it cheaper elsewhere.

IAT doesn't do anything. Of course, the maf does.

You responded on my post about taping the intake boot. Dude! that won't work. Mine is fixed with a new boot. High idle gremlins and check engine lights gone.

I tested the IATS and MAF sensors for voltage and cleaned them. Everything is normal there. I never saw those codes until I originally removed them.

Gonna order a new boot but I'm still shopping around for a good price. Lucky my job is in walking distance so I have time to wait.

I mean I can fix that boot, but apparently the crack or tear or whatever you wanna call it has been there for a long time and I don't really think its the culprit for my issue. Its not helping anything and it should be fixed but it's not the problem. Today I listened for the fuel pump and I'm not hearing it like I did after it was newly installed two months ago, which aside from making me sick to my stomach with rage, totally confuses me. Gonna check the voltage at the harness next. I gotta know through and through that the electrical side of the fuel system completely checks out before I dig any deeper into the air intake/mixture end, because fuel is obviously not getting to the engine from the tank.

You know i had the same problems w/ my I35 and it turned out to be a failing coil pack. No codes for months until it finally failed, then a CEL. Luck me, its the cylinder under the TB, so I have to take off the whole intake plenum. :(

Really??? Is there a write up on this? Never heard of the rear brackets?

The only thing holding the upper IM besides the two nuts and bolts you see on top are the two brackets in the back. Once you remove the IM, then just just remove the bolts from the block and throw the brackets away.

Update: I'm back on the road. I traced the whole electrical system back to the fuel pump, removed it, and found the O-ring fuel tank seal was broken (dunno how this happened?). Swapped in a new one and its runs like normal.