# 2012 3.5 SR coupe dying while driving problem



## Initialpatch (Oct 2, 2021)

So, I have had this problem off and on since I bought the car about a year ago. Since then it has been serviced 3 times. 
Basically the car tries to die when I press the gas pedal at a certain rpm. It doesn't do it all the time, just occasionally. Finally it died completely one 
night on my way to work. I had it towed to a local shop where they claimed it was the alternator, since my lights were dim. They 
replaced the alternator with and aftermarket version. (Bad Idea I know), but the car was dead I had no alternative as it's my dd. 
It ran fine however now my headlights and interior / dash lights pulsate with the engine idle. Brought it to a Nissan dealership and they claimed it was a 
MAS (mass airflow sensor) problem. They cleaned some debris off the sensor and said to bring it back if I still had problems. 
Lights continued to pulse with idle, so I had the dealership replace the sensor. The headlights still pulse, and yesterday, while I 
was driving a friend to pick up a rental, the car tried to die again while driving. I pulled over and put the car in park, and started 
revving the engine a bit. It would try to die at 2500 rpm every time I revved the engine. I turned the car off, and re-started it and it ran 
fine. Every time it does this turning the car off and back on seems to temporarily stop it from doing this with the exception of the headlights 
pulsing. That continues. 

So to recap, things that have been done to the car are > 

Alternator replaced (with aftermarket alternator)
Mass airflow sensor replaced
Positive battery terminal replaced (dealership said it was too small)

After all of that, the check engine light is coming on again and it is still occasionally trying to die. This feels like an electrical problem to me. 
It IS possible that the alternator is not sufficient, even though the dealership claims it is functioning properly. 
Is there anything else that can cause this symptom? A failing electronic fuel pump perhaps? I'm at a loss at this point.


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## rogoman (Dec 16, 2004)

The problem with pulsating lights is most likely due to a defective alternator. When replacing electrical components such as alternators, starters and distributors, fuel injectors and sensors, always replace with new or reman'd Nissan OEM components; aftermarket components generally don't last long, don't work right and many times are DOA. So, whenever a car is setting a multiple of trouble codes, idling funny or stalling, or anything out of the "norm," test the charging system before you start pulling hairs! You can test the charging system with a voltmeter across the battery posts while the engine is operating; it should put out a *steady* 13.2 to 15.0 volts.


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