hey, my max has 157,000 miles, i just replaced the battery cuz it died at the MA meet, and now my car will stall out occasionally at random times. i'll start my car, let it run for a few, and it may stall. i went to the drive through ATM, it was fine, then on my way home, at a stop sign, it stalled. after wondering what was up, i let it run in my driveway for a few, and it stalled after several minutes. its done this several times on me. any ideas what could be going on?? better gas didnt help, i put a new fuel filter in too. it is an Auto by the way... thanks for the help, ~Hall

 

You may have a bad Engine Coolant Temperature Sensor or a problem with the ECTS harness or connector. Low resistance means "warm engine"; high resistance means "cold engine". If your engine is at normal operating temperature and the resistance signal from your ECTS abruptly increased, the Engine Control Module would respond by making the fuel mixture richer, causing the engine to stall. You might even see a momentary puff of black smoke at the tailpipe.

Many things could cause your symptom, but this is an easy one to check. Try wiggling the wire and harness while the engine is idling. If this will provoke a stall, you are close to the site of the problem.

You may want to test your Engine Coolant Temperature Sensor. This is easy enough, requiring only an ohmmeter.

On the 4th Generation Maxima engine the Engine Coolant Temperature Sensor is located in the water outlet tube close to the engine end of the upper radiator hose. There are two sensors in that area. The one nearest the hose is for the dashboard temperature gauge. The ECTS, the one you're interested in, is right next to the the gauge sending unit. There is a good picture of these sensors in the Haynes repair manual on page 3-7.

With the engine cold, disconnect the ECTS and measure its resistance. Reconnect the ECTS, start the engine, run it until fully warmed up. Stop the engine, and repeat the resistance measurement. The "warm" reading should be a much lower value than the "cold" reading.

The manual gives these specs:
Engine coolant temperature 68F, ECTS resistance 2.1 - 2.9 Kohms
Engine coolant temperature 194F, ECTS resistance 0.24 - 0.26 Kohms
(Roughly a factor of ten difference.)

 

I am uncertain whether DBM mentioned this, but it seems too great a coincidence that you changed your battery and now your car stalls. I would suspect a loose battery terminal cable. It's an 8mm bolt, so loosen it, plant it firmly on the post, and then tighten it. Usually a loose negative battery cable is the culprit.

 

Good idea! Whenever a problem crops up, it's a good idea to ask yourself "What changed recently?" There may be a cause-and-effect relationship.

 

the battery was changed at the maxima meet actually... the posts are tight, and the cables are spotless... i dont think its due to the battery, maybe just a coincidence, the Temp sensor idea looks good, thanks

 

Try this test. Start your car then while it's running remove any battery cable. Does the car stall just as you describe?

YES = You have a cable with a bad connection someplace - not necessarally the battery post! Check the other end.

NO = Keep looking for your problem.

 

its not an instant die... its as if its losing air in the intake... its a few second sputter out stall... i think DBM is right... i hope...

 

Trust me, the terminals are VERY clean and attached corrrectly.

 

thanks for the support medic hahah they are clean though

 

Perhaps a sticky throttle plate may temporarily stick in the closed position, suffocating the engine and causing it to stall. Try getting some TB cleaner and spray the throttle plate (easy, just remove the intake hose next to it), clean it with a lintless cloth, and see if that helps.

 

Check your MAFS {mass air flow sensor}. Get a volt meter and a Chiltons manual and test it out. It sure sounds like a MAFS. 9/10 of time the MAFS seems to be the culprit of a stalling max.

Also like Daniel said, check your Engine Coolant Temperature Sensor.
I have personaly seen atleast a dozen MAFS break in the last few months and I have never once heard of one Engine coolant sensor malfuntioning. So personaly I say it's the MAFS. BTW for the best prices on used parts check out www.car-part.com . I picked up a MAFS for $55 off a low mileage 98 max. I also just bought a starter off the same car for $35! FYI 95-98 MAFS are interchangable.

 

I had the same problem not too long ago and it turned out to be the MAFS. I had just changed the fuel filter also and must have bumped the MAFS. It tested ok but when I bought a used MAFS and replaced it it worked like a charm. I would do like emax said and test the MAFS.

 

One more thing make sure you didn't bump any vacuum hoses off while replacing the fuel filter and might have forgotten to put back.

 

im at school, so im going to give the coolant temp sensor a try this weekend, well next weekend. i dont think i bumped any vacume lines, and i replaced the fuel filter AFTER the stalling started, in hopes that it may help, and i dont know the last time it was replaced...

thanks

 

This kinda sounds like the problem I'm having. The stalling is intermittent, but the car feel more like a cylinder or two is either out of sync or not operating. What's the best way to test the coil packs?

 

When the car is cold start it up and check the temp and see if it's reaching the normal operating temps and shuts down then it should be the temp sensor as it's mention in the post.
To find out if it's the MAF try revving your car to see the rpms pass the 2500-3000 mark and try to drive the car around and try to pass the 2500-3000 mark and see if it shuts down and stalls usually this is the symptom.

 

To check your coil packs you can use the stilscope thing the doctors use to check your heart beats or you can try using your hand on each of coil packs. or swap them around meaning the first bank has to be swaped with the others in the front bank not the back bank. The back and the front have different sized coil packs front ones are are small and the back ones are long.