[Mycarhurts]

Hello, I'm hoping to get some ideas on how to fix this issue on my car. It has 2.5 engine and 135,000 miles. When the car is cold it will start then die, I repeat this 2-3 times, then the car will start and continue to run. A few times recently the car has started then somewhat violently chugged and bucked for a bit then died. After chugging and dyeing 3-5 times it will start, chug, and then pop up the RPMS and run fine. There are no engine codes. I can hardly believe no engine codes occur because this is quite dramatic chugging shaking the entire car. I have pulled the MAF sensor and cleaned, nothing different. This does not happen when the car is warm, and I never experience any drivability issues once running. Any ides for me on where to start with this?

 

[Mycarhurts]

I forgot to mention that this happens much more severely and frequently in cold weather, below 10-20*F especially.

 

[d0ugmac1]

Any codes to give a clue?

 

[Mycarhurts]

No check engine light. I assume that means no codes, correct?

 

[d0ugmac1]

not true, just nothing worthy of a CEL. Definitely worth getting it read.

could be something like an ambient air temp sensor, screwing up the ECU fuel/air calculations.

 

[Mycarhurts]

Okay, I will check for codes and report back. In the mean time I'm open for any other ideas, Thanks!

 

[Mycarhurts]

I put a code reader on it. No codes. Well, there was a P0102 MAF code BUT that was ONLY because I unplugged the MAF sensor harness while the car was running - that's when the code appeared. Any ideas for me?

 

[d0ugmac1]

Can you keep it going by playing with the gas pedal? Try starting with it at 1/4 of the way down, then modulating the pedal as it tries to die.

 

[Fowardmotion]

Video?

 

[amc49]

Tune it up. The requirement for that has not gone away yet people never do it any longer, then the crap running sneaks up on you.

You need a GOOD code reader to pick up 'pending' codes, which are ones that something has gone wrong on but not serious enough to light the light yet. Not all readers can read those. The lights are damped now to stop false positives, otherwise the dealers would go crazy chasing ghosts on cars with nothing wrong with them other than maybe eating some water in the ethanol laced fuel.

A dirty TB butterfly can create some of your issue as well as weal ignition from old plugs or problems at the coil connections to plugs. Oil leaking at valve cover can dirty top of plugs to short out spark too, why you TUNE IT UP. Could be a leaking injector or weak fuel pump too.

 

[Mycarhurts]

Thanks for that. Those are good ideas, back to the basics. The TB is tucked behind the engine and sits is a semi-vertical position, do I need to completely remove it to clean it? Do I need to do an idle relearn after - and where do I find the procedure to do that? I checked for codes with two readers, one my reader that is a little cube that Bluetoothly connects to my phone and a Bosch that the local parts store uses free of charge. I'm not ready to take to the dealer yet for full diagnostic work-up, if I get to that point I'd probably hire them to fix it too ($$$$). I must admit that the problem has diminished over the last week as the weather here has gotten unseasonably warm. It's been in the upper 20's and that's warm here. There's still a slight stumble upon fire-up, but minimal enough that a video would not show it and too brief to see if manipulating the gas petal effects it. Normal cold weather will return and I'll report back once I have this better documented

 

[Mycarhurts]

I think I may have this solved. I found a dirty 1/2 stuck PCV valve. I cleaned it and the car is starting better, I honestly think it is running better too. Cold weather still hasn't arrived so the real test is forthcoming. It is the dreaded orange colored valve.

 

[carback]

Very helpful knowledge. I used to run a taxi service for carback a lot before.

 

[Mycarhurts]

Well the 1/2 stuck PCV valve was apparently not the problem because the issue is back! Start the car then buck, chug, misfire, rattle shake and die. Repeat this 3-4 times, and then like magic the car will flip up the rpms, run smooth and there are no more problems until another cold start up. This is somewhat sporadic, as is does not happen every time. It almost seems there is a certain temperature range and humidity level that must come together level to set it off. Still no engine codes which is unbelievable because it's really, really bad when it happens. Totally sucks! and down right embarrassing when it happens at work. If I hit the accelerator pedal when this is happening it does not help the situation as the misfire continues to happen, just at a higher rate due to increased rpms - I hope that may help someone let me know what the issue might be.

 

[amc49]

Fuel pressure check, may be a pump going out, it doesn't want to start moving cold. Then drags to die until it realizes it's running.

 

[Mycarhurts]

How to do a fuel pressure check with no access port on the rail?

 

[Goose182]

I vote for dirty TB. I had the exact same issues a couple years ago, and it didn't go away until I cleaned the TB. My car just started doing this again, so I'm taking that to mean I need to clean it again.

It's risky, but you can do it yourself. You have to go digging into the back of the engine to get to it, and I always have a spare TB gasket on hand. You can clean it without disconnecting the coolant lines, but its much easier if you take it to the bench. Just make sure you (1) disconnect the battery first, then (2) disconnect the electrical harness to the TB before messing with it, and (3) be VERY CAREFUL when cleaning it. you can manually open the butterfly valve by hand, just be very careful. gotta get the butterfly valve edges and the areas under the closed position to get the problem to go away. Finally, reconnect everything in the exact reverse order, and you shouldn't have to do an idle air relearn.\

Code P0101 (MAF) on 2013 Altima and warranty coverage

Hi guys - I had this code cleared earlier today by a mechanic and was wondering if my car would be covered under warranty if I took it to the dealership, I have 2013 Altima with 50,000 miles and we are the second owners. I found a TSB # NTB12-051B after searching the forum but noticed it's for...

www.nissanclub.com

good luck.

 

[amc49]

Pressure check like Nissan has to do it, rig a fixture up. You'd think they would be smart enough to simply read the computer for it.

 

[Mycarhurts]

I don't know if this will help or hurt the diagnosis, but we finally got some cold weather here. This morning -25*F. The car starts normally when it's really cold like that, -25, -13, -8 ,-5 all no problem. It never stumbles at these temps or it recovers fast enough to not misfire, stumble and die. The sweet spot for trouble is around 13-15*F up to 22-25*F, with the car at those ambient temps. That makes me doubtful of a mechanical fuel delivery problem. Also, don't know if this is related, but the car takes forever to heat-up inside the cabin (which i'm assuming is t-stat problem).
For those wondering, I don't have a heated garage so have to wait before I can start and testing, cleaning, and randomly replacing parts. Throttle body cleaning is at the top of the list.

 

[d0ugmac1]

You know, I'm starting to wonder if it's the ambient air temp sensor....given your new info. Do you have an OBDII that can read the sensor data...if so, check and see if the air temp is relatively accurate. I've seen some reports where when the sensor fails or is disconnected, that it always thinks the air temp is -40'F or something...this will really mess up the air fuel calcs being made by the ECU and could lead to stumbling. Worth a look anyways.