02 Pathfinder won't start /won't stay running ?

[npathquest]

I have a 02 Pathfinder SE that was running great until the engine suddenly shut down on the freeway at 70mph. After it sat for about an hour it started right up and ran smoothly until it suddenly shut down again about 10 miles farther down the road. I drove it to an auto repair shop close by and they had it for 3 1/2 weeks. Shop manager told me they had checked all sensors and wiring that could be causing the problem and they were good. They couldn't find what was causing it to shut down suddenly and start up later without any sign of a problem other than PO340 engine code which they checked. I took it home and put new crank sensors on both front and back plus changed the PO340 cam position sensor and cleared the code. Still shutting off suddenly and not starting plus giving the same PO340 code again. If the engine runs for just a little while in idle and I turn it off it won't start until it has sat for a while. I changed the ECU/ECM,... did the relearn procedures and when I turned it off after I had it running great it wouldn't start until I let it set for a while then it started right up running smoothly. Does anyone have an idea of what's going wrong with my engine?

[atraudes]

It feels like an electrical issue like a bad ignition switch or something, but it's hard to say.

Check the oil level for kicks and giggles.

Here's two similar threads that may help:

post6065702.html
post4652361.html

[npathquest]

Thanks ataudes for the threads. Oil level is good
My new ECM is now reading the same PO340 code. Could it be my Idle Air Control valve causing my problem?
Would I get a code if its bad?

[Towncivilian]

Have you tried loosening and retightening the engine ground screws?

P0340 is not related to the idle air control valve; you'd be getting a P0505 code if your IACV was not operating properly.

[atraudes]

Ah! Missed that it was still throwing that code Excellent; that's something to work with.

Check out the Engine Control System (EC) FSM. There's a whole section devoted to that code (P0340, not Po340) and has some troubleshooting procedures. It doesn't seem likely that the sensor's bad since it's brand new, but there's a simple testing procedure for that as well. You'll need a multimeter.

http://www.nicoclub.com/FSM/Pathfinder/ ... der/ec.pdf

[2003 PathGrinder]

Had this SAME thing happen to me and it was an easy no cost fix. In my situation, before it had the start/ idle problem, the battery was disconnected during a front end collision repair. After driving for a half hour or so it did the same thing. It would not start or stay idle. I did some research and found this to be a common problem when disconnecting the battery. I was instructed to go through an "idle re-learn", which essentially is teaching the ECU to keep the idle at where you want it. Other wise it will not keep an idle. What I did was turn the car on and had my foot on the gas a little. Then I just kept it at about 800rpm for about 5-10 minutes by applying light pressure to the gas pedal. After I did this, it stayed right at 800. Never had an issue since! Your case may be different though, just wanted to share my experience with this issue! Thanks!