Having trouble solving engine stalling problem

[ajonesjr]

I have a 2 wheel drive 2001 Pathfinder SE with 125k miles. Started experiencing random engine stall at red lights, then it progressed to constant stalling. Engine runs fine in the morning for about 5 min then rpms drop and stalls, it cranks right up and will run for about 60 seconds then stall. No SES light tripped or codes are stored. I replaced the spark plugs ($60) and fuel filter ($12). No help. I did some research and this seems to be a common problem, I bought and installed new crank shaft sensors (front[$65] and rear[$90]) and cam timing sensors ($65x2), plus one on the front cover($65), figuring that if they weren't the problem they likely would be soon. Disconnected the battery for a couple of hours and reconnected it. Problem is still there. I've also tried lightly tapping on the Variable Cam timing solenoids as it stalled in case they were "sticking", but nothing has made a differance. I've read that there might be some problems with the "swirl valve and actuator" but I'm not sure how to test for a problem with that. Also I've read that the EGR valve can stick open causing a similar problem, but I'm damned if I can find an EGR valve. I have an engine components guide but it's not listed.

Any help is appreciated
Modified by ajonesjr at 10:54 AM 8/11/2008

[ajonesjr]

Looks like there is no EGR valve on the Pathfinder 01-04 3.5L engine... Oh well, at least I don't have to buy one.

What about the MAF sensor? Or the Swirl valve and Accuator? Any idea on testing those components?

I've spent $400 in parts already and I wanted to have this car ready for a trip to Florida in 2 weeks, wife is nervous about taking it.

Any help would be great

[ajonesjr]

I spent some time tinkering today and trying to get more info. I tried removing the MAF sensor and cleaning it, but it didn't look dirty and it didn't help. I actually tried unpluging the MAF sensor and running the car, seems to run just about the same without it. I tested the resistance on the terminals, but I have no referance to tell me if the numbers are within spec or not. Right now I'm leaning toward the MAF being the problem, but I'll have to fork over another $100 or so. I would just like to be a bit more sure...

[ajonesjr]

Ok, turns out unpluging the MAF does affect the performance quite a bit, but only of your trying to go fast :P

The engine stalls like clockwork runs 2mins then RPM's are down to 0-500 for 5 seconds then idles back up to normal if it doesn't stall completely. Makes me thinks its timing problem...

[ajonesjr]

Well I bit the bullet and ordered a Maxima Mass Air Flow sensor from http://www.thecarpartwarehouse.com for $91.70 w/free shipping.

I unpluged the battery and installed it. That seems to have solved to problem.

It just seemed odd that there were no codes stored and that the MAF looked clean and no mechanic I took it to seemed to have a clue about what the problem could be (except one who changed out my front crank pos sensor, after that I figured I could throw parts at it as good as the next guy).

It would have been nice to pinpoint the MAF to start with, but I can't feel too bad about having 6 "known problem" sensors replaced for $500.00 or so. Just the MAF at the dealer would have cost me that and more. So thank you NICOclub for the good info on this site.

Hopfully this post will help the next guy who is having similar problems.

[ajonesjr]

Update: Car has been running fine until yesterday. I noticed a pinging noise, soon after the SES light comes on. Pulled the codes today: P1135

Great. I'm beginning to think I can expect a problem annually with this Pathy.

Is there any way of knowing if the computer has been reprogrammed (according to the service bulletin my VIN doesn't not require the update).

Also, about a month or so ago I switched to synthetic oil, would that make a difference?
Modified by ajonesjr at 11:24 AM 7/23/2009

[ajonesjr]

Update: Swapped my CTP sensors, now getting P1110 instead of P1135, so it's the sensor. I just replaced it about a year ago, they cost about $60-$80. I've put about 15k miles on on the Pathy since then. I'll see if buying a higher quality part will make a difference.

[Pwnin O'Brien]

Apparently this is a pretty common issue on this year. The manual says to check for a crack in the signal plate at the camshaft for the camshaft position sensor. Most people that have this issue say that you should just check the sensors (Camchaft and crankshaft position sensors) for any wear and clean them.

From what I have read you can drive the car without any problems, just an annoying SES light.

[ajonesjr]

Update:

Ok, I'm a bone head. Turns out if your engine oil level gets too low then air bubbles form in the oil and won't allow the IVTC solenoids to function properly, thus generating an error code.

I had a slow leak for a while and was too busy to fix it, then I changed over to synthetic oil.

Here is some fun math I failed to consider:

If I change my oil every 3k miles (normal oil) and I'm a quart low, it's not that big a deal, But...

If I change my oil every 10k (syn) while loosing the same amount of oil over time, then I've lost 3qt's of oil when it's time to change!!! That's a big deal and will cause you much more expensive problems than a pesky SES light.

Needless to say I will be fixing my leak pronto.....I wonder why my oil sender didn't send a code? I'll need to look into that as well....

I hope this helps others solve those pesky problems.