hi all,
This problem has been going on for about 5 months. Happens once every 4-8 weeks.
2005 Nissan Xterra S 4.0L V6 175K
The engine will crank but not start, like its out of gas.(no codes pop up) When towed to the dealer it will start right up, and start every time. (Last time they kept it for a week, I even let the tech drive it to and from work. never failed once).
The second time it went to the dealer, the fuel pump was at fault (apparently coincidently). Fuel pump was replaced.
Problem keeps cropping back up.
Crapped out on me again yesterday. Today it tried to catch twice, then went back to just cranking
So far these components have been replaced:
Fuel pump (which includes non-servicable filter)
IPDM (which includes the ECM, fuel pump relay and injector fuse)
Crankshaft position sensor
Fusible link block on the positive terminal+terminal itself (battery was only 3 months old when this started. Heavy duty battery as well)
All the grounds I can find have been checked
So now I am at a loss. With no codes being generated, and every time it gets to the dealer it works perfectly, I’m not sure what to do next.
(Shout out to Power Nissan in Salem OR. They’ve been great. Never charged me a dime [other than the fuel pump of course])
Any and all suggestions please!
One time I had a problem where the car would crank but not start, but when towed to the dealer it would start then. That turned out to be caused by a flooded engine condition. The trip to the dealership was enough time for the fuel to evaporate I guess. Sometimes the engine will flood if an injector leaks from the fuel rail into the intake manifold when the engine is turned off. Long shot, but worth considering anyway. The way you’d prove this is to remove the spark plugs when it happens, crank the engine to expel any gas, then if it starts up you’d have a pretty good clue. Check for wet gasoline soaked tips on the spark plugs too.
Beyond that, your shop will have to go back to the basics. For an engine to start it requires just some basic stuff. Your shop will have to go through that one by one, at a time the problem is occurring.
- spark at the spark plug, at the correct time
- the correct fuel pressure at the fuel rail
- the ECM must detect that the crankshaft is turning
- the injectors must be pulsed by the ECM and injecting gas
- good compression in all cylinders
From what you say, the dealership seems to being doing what makes sense. There’s a couple of weird problems that are unlikely causes, maybe worth a try
- The cat might be failing, and sometimes the innards adjust themselves in a way the exhaust system is plugged up.
- There may be something blocking the air intake, like a birds nest or something, and it shifts around.
My old Ford Tempo use to do that. The ignition module was overheating and prevented the car from starting. If you let the car cool down a bit the car would start fine.The only fix was to replace the faulty ignition module by a shielded one. Ford never issued a TSB for this defect eventhough they were aware of the problem.
Appreciate the responses, 
one thing I forgot to mention, the truck is cold when this happens, having sat at least 8 or more hours.
Doing a fuel pressure test tomorrow, I’ll take a look at the injectors, but I’m thinking if one was leaking, it would try to catch rather than just crank. But long shots are about all I have to go on at this point. 
Also looking for vacuum leaks, and wondering if i have a collapsing fuel line.
The cat idea is something I’ll look into, just started getting a cat warning code off and on in the last couple weeks. Although I hadn’t had any codes when this happened before.
Since the dealer never had a problem driving it for a week, you have to look at your startup procedure, what could you be doing different, or what environmental differences are there…
One point that comes to mind, are you keeping your foot off the throttle when starting? Do you pump the throttle before starting?
or, if it;s too intermittent, ie, time between failures is too long, just wait until the period decreases and then take it back to the mechanic and have them keep it for another week.
I have been beginning to suspect humidity as a factor, just not sure how. When it first occurred it was cold and rainy. The last 2 times its been hot with high humidity
According to carcomplaints.com this 2005 Nissan has the most complaints. This one came to my attention:
2005 Nissan Xterra ENGINE AND ENGINE COOLING
NHTSA Campaign #10V517000
Date Announced:
OCTOBER 28, 2010
Vehicles Affected:
747,480
Summary: Nissan is recalling certain model year 2004-2006 armada, titan, infiniti QX56 and model year 2005-2006 frontier, pathfinder and Xterra vehicles. The intelligent power distribution module (ipdm) assembly contains an engine control module (ECM) relay that has a diode for electrical current noise reduction. The ECM relay may allow silicon vapor to form and, over time, the silicon evaporates from the diode molding which causes silicon oxide to develop on the ECM relay contact due to arcing.
Consequence: This could cause engine stalling increasing the risk of a crash.
Actions: Dealers will replace the ECM relay inside the ipdm assembly. This service will be performed free of charge. The safety recall began on December 6, 2010. Owners may contact Nissan at 1-800-647-7261. For detailed information & supporting documents, see the official NHTSA page concerning recall #10V517000 »
Does this make any sense to anyone? Doesn’t to me !
Perhaps they mean the diode is not properly sealed, and when it gets hot, silicon vapor is released. But that takes some pretty high temperatures, enough to kill the diode.
edit: caught the word “molding”. Perhaps the casing of the diode is glass, and the silicon evaporates from that. But it would have to be very hot, again.
Not to me. I’d guess that someone in the technical writing department got a little overzealous in their explanation for what a more simple description such as this would suffice: Nissan got a batch of bad ECM relays that need to be replaced.
Actually ran out of time, so ended up sending it back to the dealer. Hopefully it won’t start right up for them again. Fingers crossed. 
I did manage to get it to cough a bit by spraying ether in the throttle body
It’s actually had I think 5 ECMs in it. The previous owner replaced it back in '09. I swapped it out out a couple times, as did the tech. I even replaced the whole IPDM.
I freely admit I have little experience with EFI. So can anyone out there tell me if high humidity could cause a strong crank/no start condition in any of the components? Perhaps something in the throttle body?
Some days I really miss carburetors
I’ve been through a few fuel pumps so don’t discount the pump again. I had them fail in a year and one six blocks from the shop. I also had trouble with the connector to the pump and also replaced all the wiring from the pump to the computer. Electric pumps can be fussy and you are supposed to replace the relay as well as the wire harness with a new pump. I used to drive around with the fuel pressure tester pasted to the windshield waiting for it to fail so I could pin point the problem. If not the pump, then a long list including the ignition switch.
No, high humidity wouldn’t normally affect the EFI system. High humidity shouldn’t affect anything of course, except if a part were faulty or connector corroded. The most likely high humidity affected parts would be in the high voltage section of the ignition system. Coil packs, etc. Best of luck there OP. Intermittent problems like this are very frustrating for the car owner. If you can get one of the dealer service techs to drive your car to and from work, eventually it will fail and the tech will be able to at least narrow down which system is failing; i.e. spark or fuel system.
UPDATE.
Looks like it was the fuel pump. I’m now at 6000 miles on the new pump and no problems.
Thank you for all for your help!
Happy you are back on the road with a reliable ride. Good for you. 
If your fuel pump conks out the second time, you may have a restriction in the fuel supply line to the engine, or you may not be getting full voltage applied at the pump, which could cause it to spin too slow and draw more current than it is designed for.