2001 Pathfinder 4WD - Rough Idle, Stalling, Now No-Start

[mmoon]

Hey everyone,

I've done a lot of searching through the topics here with a lot of helpful information, but still can't seem to pin the problem down or decide on my next plan of action. I'll try and list all the symptoms in the order they occurred and what we have tried.

It started a while ago with the occasional tremor. I noticed it, it seems, at both highway speeds and while idling. It didn't happen very often. Then it seemed to get rough while idling. At some point we noticed a smell while traveling on the interstate going up a pretty big hill. Husband said it was an antifreeze like smell burning. We at some point put in some fuel system cleaner, changed the fuel filter (wasn't clogged) and looked at (honestly I don't entirely recall *what* he did at that point) the spark plugs. After messed around under the hood we tried to drive to the store and it started shaking HORRIBLY and died. He could get it started, but then it would die if he accelerated more than the tiniest bit. Going VERY slowly he got it up the driveway and replaced the plugs and wires and it was back to where we were.

That put us at very rough idling (nearing stalling, but not quite). We were running low on fuel one time (on way to gas station) and it was idling rough and stalled, but started right back up. Then for a while it was okayish (still rough) and one day it died while idling in a drive-though, restarted and then died at a stoplight and it hasn't restarted since then.

At some point through all this we got a knock sensor code and a misfire code. He's followed some testing suggestions and got a spark tester and is pretty sure that there is no spark. The engine is cranking over and we can hear the fuel pump come on, but no starting.

So...where do we go from here. Should we give up self-diagnosing and take it to a mechanic/dealer? Obviously I'm not *terribly* experienced, but I do enjoy learning and helping figure out what is wrong.

Any suggestions would be greatly appreciated!

-Alicia
Modified by mmoon at 8:08 PM 6/30/2009

[KILLERME]

If this is a VG33 engine, Most comon is crank sensor , which is the whole distributor. If definatly no spark. clear fault codes by disconect battery then try and start again, then check fautl code, if coming up crank sensor that will be problem, knock sensor is common fault, knock sensors dont like heat under intake on block, 140k plus they start to f*** out, knock senson will not cause any noticable engine loss in performance, but should be replaced, big $. check all fluid levels, check for spark while cranking. To do this remove one plug lead from spark plug on engine, jam a spare spark plug or screw driver in the lead hold close to metal part on engine. while cranking or runnig this should spark like a heart beat. If got good spark, check leads on cap haven't been put in wrong place. all it takes is for one lead mix up and anything will run like s***.Got the spark and leads right, then I would check fuel pressure with gauge, if haven;t got one squeeze fuel line from filter to engine then turn key you should feel it prime and go hard. If got running at idle squeeze hose and see if going soft when engine starts to die, if so you have fuel pump or fuel relay problem. if ok move on, unplug air flow meter and try in fail safe mode. It will let you rev engine to 2000rpm only, but should be smooth reving up to those revs, if it is faulty airflow meter. If no change when unplug air flow it Aint airlfow meter.Good luck,

[PlaneAddict]

I'd like to throw in my two cents. Had almost the exact same problem with my 1997 Pathfinder, 3.3L (VG33). I was getting P0300, P0305, then P0306 misfire codes along with the obligatory P0325 Knock sensor. After doing just about everything, (plugs, cap, rotor, looking at injector, cleaning mass air flow sensor, pull front of engine to check timing belt alignment and tension, set timing), it was down to performing a fuel injection cleaning as described in the service bulletin NTB01-033 for this model, "Fuel Injector Cleaning for Vehicles with Rough Idle, Hesitation or MIL 'On' with DTC P0300-P0306 Stored." That bulletin describes a cleaning service that dumping Techron in the fuel tank won't resolve. After taking it to the Nissan dealer, he looked it over and first suggested I change the spark plugs from my Autolite Platinums to NGK's. I thought, well, that's not going to do anything except raise my bill! I had Autolites in there when I bought the car, and changed to Autolite Platinums after I started noticing the rough idle which was now progressively getting worse. I even changed out plug #6 which most folks ignore! I took the car home without service, then changed the plugs to NGK GP-Platinums anyway (about $3 a pop). Guess what? Runs smooth and solid. I couldnt believe it. Really? A different brand plug? They were both made for the Pathfinder, but it made all the difference. I owe the dealer some kudos for thier willingess to REALLY help instead of charging me for a cleaning service that wouldnt have resolved the problem.