# 1995 Maxima randomly stalls and sometimes chugs



## MechanicalHobby (Mar 17, 2011)

I'm currently trying to repair my mother's 1995 Maxima. It randomly stalls, and I've done everything I can think of. I've replaced the Ignition Coils, Fuel Pump, changed the IAC, Idle Control, cleaned the MAF Sensor with MAF Sensor Cleaner which cost nearly $25 for the spray can from SuperCheap Auto (an ironic name), in AUS. Air Filters are all clean, and beginning to think it is a computer problem. Apart from stalling, if it doesn't stall, the car will run great.

A mechanic charged my mother around $1,000 for new ignition coils to fix the problem, though it never did. When I checked the ignition coils, noticed not all were replaced so I replaced them all.

There are no check engine light popping up, nothing. But there is clearly a problem! My mother is afraid to drive it.

I did notice something, I checked the voltage of the Ignition Coils while the Maxima was running, and the MAF was disconnected, and the meter read about 13+volts consistently. However, when I reconnected the MAF Sensor, and ran the car, the voltage of the Ignition Coils would keep randomly jumping to a low voltage and back up to 13+volts. Sometimes the meter would read less than 1volt, and jump back up, and then randomly to 4v, then sometimes 7v etc etc.

I even resoldered the MAF Sensor pins since they seems shonky. Though that didn't seem to help. I tried driving with the MAF Sensor disconnected and the car will run, though not drive and stall a lot more.

With the MAF connected since yesterday, engine wouldn't start again this morning, so I unplugged the MAF Sensor, and tried starting and it still wouldn't start... just smelled like gas. Have to wait a little, then try and start and rev it quite a bit when starting and then it eventually goes. Chugs sometimes while driving, though usually stalls at red traffic lights, or a stop sign. The stalling issue seems to be a common problem though with different causes.

It is annoying because it is costing a LOT of money. If it was the MAF sensor, it should have started this morning when I unplugged the MAF Sensor as I had read somewhere, since the car wasn't starting, so there has to be a root cause.

I did a voltage test on the ground cable after reading a thread about the ground wiring, and noticed the voltage was about 0.013v which changed between 0.012v - 0.014v, though usually stuck around 0.013v consistently. Is that a sign of a bad Ground Connection to the MAF Sensor?

I'm not pro, but I would like to hear some other opinions so I can try and get this car running nicely again.


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## jdg (Aug 27, 2009)

Crank and/or cam sensor. I don't see them listed and both of them are DIRECTLY related to whether or not you get a spark signal for the coils.
Sometimes they'll set a code, sometimes not...


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## MechanicalHobby (Mar 17, 2011)

jdgrotte said:


> Crank and/or cam sensor. I don't see them listed and both of them are DIRECTLY related to whether or not you get a spark signal for the coils.
> Sometimes they'll set a code, sometimes not...


I took the Crankshaft Sensor out and noticed it was really dirty, I did try cleaning though that didn't change, however I have another Crankshaft Sensor I bought which I'm swapping today. I'll see if I can check the a Cam Sensor. Is there a way I can test to make sure this is working correctly, maybe with a ohmmeter/multimeter? Thanks


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## jdg (Aug 27, 2009)

With a meter hooked up while you're cranking the engine, a meter _might_ tell you if it's completely dead or not, But if it's not completely dead (i.e. putting out some sort of signal), it won't tell you for sure if it's functioning 100% correctly.
You could check it with an o-scope, but even then, it's a bit iffy as to whether or not it's putting out a good signal with the engine running, although a 'scope would be a fairly decent indicator as to whether or not you've got a smooth signal.


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## MechanicalHobby (Mar 17, 2011)

Thanks for your help. In regards to the Cam and Crank sensors, I need to correct myself. I got confused with the both and it was actually the Cam Sensor was really dirty of which I cleaned, which I replaced today. It didn't make any difference, though it was replaced with a 2nd hand one from the car wreckers from another A32 Maxima, though a 1997 model. The stalling didn't make any difference.

While driving today to try and get MAF Sensor, the car was chugging a fair bit at first, then phased out and then only chugged off and on like it normally does. When I had started this afternoon, I could clearly hear the engine trying to start though took quite awhile to fire up. I had to give it a few good revs to eventually get it started. Sometimes it takes less than a minute to start, and sometimes it can take a lot longer to start. Though, most of the time straight away.

Are there two crank sensors? I searched online and found a layout showing two crank sensors according to this layout:
http://ww2.justanswer.com/uploads/shimell/2008-05-15_153647_3.gif

Do you know where the Crank Sensor/s are located? Do I have to access them from under the vehicle?


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## emjee (Aug 26, 2012)

Just wondering if you ever found out what caused your stalling problem?


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## MechanicalHobby (Mar 17, 2011)

emjee said:


> Just wondering if you ever found out what caused your stalling problem?


Defiantly. It actually turned out to be very simple and the problem was cheap to fix (not overall though since we tried many things).

I was able to get the codes off the ECU which showed it was a Thermostat Sensor. When I pulled it out, it was corroded, so basically in bad shape. Got a replacement for I think like $25 or $35 and it fixed the problem. Never did have it stall again.
When a sensor goes out, then the air and fuel mixture can be affected as a result. The computer not knowing exactly what the temperature was I guess would cause the mixtures to be affected, thus the engine stalling.

What got me is the mechanics had the equipment to read the OBD codes, yet they kept failing and charging my mother a lot of money for their work that was only temporary if even.

Thankfully for the Maxima, at least this generation, it allows you to get the OBD codes without even having an OBD reader. All you really need is a small flat-head screwdriver. From memory, I learned to extract the codes from this video:





By the way, thanks for asking. Hope this information helps for anyone else who has this problem!


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## emjee (Aug 26, 2012)

Thanks for that info MH. I had a 50-50 chance of it being the Mass Air Flow sensor or the thermostat sensor. I went with the MAF, and hopefully that will do it. BTW, what is that black box unit (leaning against the console) that is being adjusted with the screwdriver in the video?


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## MechanicalHobby (Mar 17, 2011)

Hopefully you can get your Maxima to run nicely again.

The black box unit, also can be a steel or silver box, sometimes plastic maybe, is actually your ECU (Car's Computer) which stores all the codes when something goes wrong. It also learns from the driver as well as control the air and fuel mixture. Without it, your care would basically be hopeless. If you're getting stalling, the check engine light will not always come up. But at least using the screwdriver will allow you to pull those codes. Basically as the video shows, the check engine light will flash at different speeds for the codes.

Defiantly try and get your OBD codes from the ECU. That can tell you a lot of things and pinpoint exactly what is wrong, in turn saving you a headache and time!
It could be any sensor playing up, so getting the OBD codes will help a lot.

When the Check Engine light flashes the code/s then write them down as it gives it to you. Then compare your codes to a Trouble Code website for OBD/II

TroubleCodes.net- engine & OBD2 Trouble Codes and Technical info & Tool Store.
And more manufacturer specific for Nissan:
Nissan OBD-II Trouble Codes


Could you let us know if playing with the MAF sensor works for you? Or if you get your's to work?


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## emjee (Aug 26, 2012)

OK, I see. Thanks!


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