Stalling randomly

[EricCR]

This hasn't been a good year for my 2003 R50. I had to buy a brand new AC compressor, then a new starter motor and now the car is stalling with seemingly no rhyme and reason to it. It may do it with a cold engine, or hot, at idle or under acceleration. Sometimes it starts right up, sometimes it takes 2 or 3 cranks after dying. Sometimes it also idles extremely low but doesn't stall.

 

I've read a ton of threads of similar issues, but they are for the most part for the VG33 or about the IACV that I believe my car doesn't have (it's throttle by wire).

 

My scanner shows 0 codes, the check engine light has not turned on and when the car is working fine it pulls strong.

 

Any ideas of where to start? I can leave it idling for 30 minutes in driveway and it may or may not stall, so it's time consuming to be right next to the car when it stalls and it may not do it again for a long while. It has become more and more frequent, though.

 

Thanks!

[03TroutFinder]

Not sure if this is the same issue, but mine did that at times going down the highway. Only happed a few times over the course of a year, but ended up being the crankshaft position sensor. No issues since I changed

it out. Cheap and easy to change out. I believe mine went bad due to getting exposed to wet conditions like creek crossings, etc.

[EricCR]

Did you have any codes/check engine lit?

 

I am testing the MAF, wiggling all the wiring under the hood in hopes the car stalls, but everything seems ok at a glance.

 

It feels to me like fuel starvation, but when my fuel needle was bad I actually ran out of fuel and the way it stalls is not the same. Also, pumps usually either work or don't. I've seen several threads of people replacing the fuel filter and that didn't fix it either. I will still change it for peace of mind, but something electronic seems more likely.

[EricCR]

Ok, I narrowed the problem down.

 

It only stalls when the engine is hot and only when coasting or idling (no throttle input). Under throttle the car behaves perfectly.

 

If anyone has any ideas I'd really appreciate it. I don't want to simply throw parts and money at the problem. I'm getting no codes so I'm at a loss. I cleaned the MAF and added RedLine fuel cleaner, but the problem is getting worse.

 

EDIT: Can someone with a 2003 throttle-by-wire Pathy confirm if the MAF is 22680-CA000? I believe mine has the wrong MAF, clearly told apart by one having the torx screws holding the sensor in place in a straight line and the other having them in diagonal. My car's build date is 07.2002 so I'm confused about being one or the other. Anyone knows the change year/month for these MAFs?

 

EDIT 2: It seems the cutoff date for the newer MAF is 5/03. So mine uses the older one (bottom pic).

 

EDIT 3: To continue with my monologue, I had a conversation with my mechanic and he concurs that the crank sensor should be the first thing to replace, followed by the MAF. I'll get both things since I don't want to wait for shipping and the 2Y001 MAF is still relatively cheap. I'll also replace the fuel filter while I'm at it and it's recommended after using a fuel cleaner additive anyway. I'll post an update once I replace all that stuff.

 

CA000:

 

2Y001:

Edited September 1, 2023 by EricCR

[Slartibartfast]

I doubt the wrong MAF only started being a problem recently, after running normally for however long it's been in there, but your symptoms are pretty close to how my WD21 behaved when the electrical connector for the MAF was acting up. Check the tube from the MAF to the throttle body while you're in there, make sure it's not torn. I would also check the filaments on the old MAF for any obvious contamination.

 

The fuel filter's not a bad idea for preventative maintenance, but, yeah, I doubt it's related.

 

Normally I would suggest cleaning the throttle body, but I've read horror stories of the drive-by-wire computer noticing the difference, deciding the throttle body is broken, and needing a trip to the dealer to convince it otherwise, so maybe leave that one well enough alone--or at least do your homework first.

 

Hopefully the first shot from the parts cannon gets the job done!

[EricCR]

Thanks, man!

 

It didn't take long for the problem to finally identify itself. Last night I got the check engine light and the car went into limp mode. It was a long, stressful drive but once I got home I scanned the stored codes it was the MAF (P0103).

 

So I'm ordering a new one. I'm getting the Hitachi MAF0094. It's still confusing as I see some small differences in the way the sensor is built. I'm getting a 5 pin MAF since that's what I have now and matches my production date. I hope they work identically. I am aware of the need to migrate the thermistor to the new part in case it doesn't come with it and the ECU reset procedure, but I believe the MAF0094 is a 1:1 replacement so fingers crossed I won't need any of that. While I'm at it, I'll also get the CPS and new air and fuel filters. I won't touch the throttle body as per your warning.

 

For future reference, the 5 pin MAF is used between these production dates: From 07.2002 to 05.2003, so it's basically the least used among R50s.

• Before 07.2002 you need the 4 pin MAF.
• After 05.2003 the MAF is the one in the screenshot above with the sensor screws in diagonal. It's the same MAF that most newer Nissan's use, it's cheap and easier to find. You can retrofit it by swapping some wires around but you also need to reprogram the ECU, so nah.

While I wait for it to arrive, I took apart the sensor and exposed the circuit board to look for signs of damage, burnt resistors, broken solder, water damage, etc. I saw nothing out of the ordinary so I did a board "reflow". I used a heat gun to slightly melt the existing solder in hopes it would fix any broken points. Normally you'd use tinfoil to protect any areas you don't want to overheat but since this was already bad I said what the hell and heated the whole thing. I always use a little piece of new solder and place it nearby so when it starts melting I know when to stop.

 

I resealed it and put it back and the car is amazingly working fine. I cleared the code and it's not stalling. I need that band aid fix to hold at least until Monday and then it can implode if it wants. It's getting its Takata airbag replaced (finally!). I don't want to drive all the way to the dealer in limp mode.

 

 

Edited September 2, 2023 by EricCR

[Slartibartfast]

Oh, nice! Good to know that's what goes wrong with these. If the reflow keeps working, keep that one on the shelf as a spare.

 

And yeah, get that Claymore outta there.

[EricCR]

Well, that fixed it. For my build date the Hitachi MAF0094 is the correct (and OEM) part.

 

I had to do the air flow reset procedure to get it to idle better (lower) and it's as good as new.

 

I also bought an Hitachi CPS just in case the MAF was not the culprit. Would you still replace it just to have the brand new part or would you save it? I'm undecided.

[Slartibartfast]

Unless it's easy to get to, or you have a good reason not to trust the old one, or you're in there for something else anyway, I'd probably leave it on the shelf.

[EricCR]

It's rather easy to replace but the one in the car is working fine I think. I'll leave it be for now.

[thatotherdriver]

On 9/18/2023 at 10:33 AM, EricCR said:

Well, that fixed it. For my build date the Hitachi MAF0094 is the correct (and OEM) part.

 

I had to do the air flow reset procedure to get it to idle better (lower) and it's as good as new.

 

I also bought an Hitachi CPS just in case the MAF was not the culprit. Would you still replace it just to have the brand new part or would you save it? I'm undecided.

Hello I’ve read through this thread and determined that my r50 may benefit from some MAS maintenance. How does one conduct an air flow reset procedure?

[EricCR]

It depends on the year. AFAIK this is only valid for throttle-by-wire Pathfinders. Here is the procedure: https://www.nissanhelp.com/diy/pathfinder/projects/nissan_pathfinder_idle_air_volume_learning.php

 

Notice that before doing the air flow reset, you must do a couple other procedures beforehand. You feel like someone's trying to pull a prank on you, but that's really the way it's done.