97 Maxima stalling, sputtering when engine is hot

[zorobabel]

Hopefully I get some ideas. I'm having this sudden (as of yesterday) problem with my 97 Maxima (with a slushbox).
The symptoms are (only when engine is hot):
1. stalling when coming to a stop in drive, when the engine would go from almost no gas to having to keep idle - some (sudden) load on the engine. Once stalled, I can crank it to start again. Putting the tranny in neutral right before the stall saves the idles. No stalling in neutral or park so far.
2. sputtering (behaves like running out of gas) around 1500 rpm with more than a light load on the engine, like going up hills or accelerating from a stop.

The only thing I did different yesterday before the issue occurred was driving rather spirited, including up hills. It was also a hot (100F) day. My OBDII code reader can't find any codes.

 

[spasm3]

Iac valve? perhaps throttle position sensor?

 

[irad]

Could be one of the following sensors. MAF, camshaft position, crankshaft position in that order. The MAF can be cleaned with MAF cleaner or brake cleaner.

 

[spackard]

Vacuum leak.

 

[slacktide_bitog]

TPS and MAF failures are both very common on these cars. The knock sensor is also a regular maintenance item.

If it's the MAF, only buy OEM, Beck/Arnley, or Bosch.

 

[donnyj08]

Originally Posted By: slacktide_bitog
TPS and MAF failures are both very common on these cars. The knock sensor is also a regular maintenance item.

If it's the MAF, only buy OEM, Beck/Arnley, or Bosch.




+1

Take the cover off the MAF sensor and check the three wires at the solder point. It's not uncommon for the solder joints to be loose.

 

[zorobabel]

Thanks for the replies!
I will update the thread next Sunday after I'm back from a trip.

 

[Merkava_4]

All you guys are forgetting about the MAP sensor.

 

[3800Series]

My guess would be TPS as well. I've had this problem in one of my cars and it sounded identical to what you are saying. Keep in mind those the wiring harness for them can go bad or the connectors can foul up.

I would recommend checking the harness before you replace any part.

 

[Revving2Redline]

MAF or 02/Fuel Filter and spark plugs

 

[Mr Nice]

Originally Posted By: irad
Could be one of the following sensors. MAF, camshaft position, crankshaft position in that order. The MAF can be cleaned with MAF cleaner or brake cleaner.


Yep.

 

[artificialist]

Sometimes certain ignition coils fail intermittently and can cause that problem. Although OBDII is supposed to detect misfires, it isn't perfect and can fail to detect misfires.

 

[slacktide_bitog]

Originally Posted By: artificialist
Sometimes certain ignition coils fail intermittently and can cause that problem. Although OBDII is supposed to detect misfires, it isn't perfect and can fail to detect misfires.


Yeah, but that wouldn't occur only when the engine is hot, though. The coils are electronic, so their operation doesn't depend on temperature. They'll work equally well (or poorly) at any temp. And even a single misfire can make the CEL blink. The Maxima has 6 coils, so even if one of them failed, the other 5 would still work and wouldn't cause stalling issues.

Coil failure is much more prevalent on 99 Maximas than on 95-98 models (they switched suppliers for 99, and the new ones weren't as good)

 

[zorobabel]

Thank you for the replies!
With further testing (driving), the car does stall in park at times (not only in drive) after warming up for only 2-3 miles.

I tested the TPS and I get 0.6 kOhm at idle (I have elevated the idle a bit from the adjusting screw - to 700 rpm), then (most times) just as I start moving the throttle I get a spike to between 1 and 15 kOhm, then drops down to bellow 1 and continues gradually until 3.85 KOhm at full trottle. I'm not sure this is the expected behaviour. Manual says 0.5 kOhm at idle to 4 kOhm at full trottle.

I checked the MAF voltage, with a warmed up engine I got the following (within manual specs):
Ignition on, engine off: 0.35V
Idle: 1.25V
2500 rpm: 1.9V
4000 rpm: 2.3V

 

[mk378]

Resistance should change smoothly and continuously as you move the throttle. No spiking.

 

[Kurtatron]

Check your spark plug wire resistances and compare to manual. These degrade with miles and time and can act up with temperature swings. I find thes things fail more often than non-wear components like sensors.

 

[zorobabel]

Thanks Kurtatron. This year Maxima has a coil on plugs setup, no spark plug wires.

I replaced the TPS, and while I feel good replacing the defective part, it hasn't cured my problem.
I also cleaned the MAF and throttle body (not too dirty, I've had cars with way dirtier TB run just fine). The problem is still there, just that the idle is at higher rpm now (I have messed with an idle screw on the IACV 2 years ago).

So the car has to warm up, and then (especially if it's hot outside) the engine sputters and stalls given the opportunity. It does so randomly, it does it at one trafic light, then it's fine at the next one, then it might do it again at another traffic light. When it has its moods, pressing the gas pedal harder eventually makes it snap out of it, allowing me to keep driving. If the fuel pump was bad, I imagine I would have problems accelerating...
The exhaust pipe has some soot in it now, instead of being clean and half rusty as before.
I would compare the problem to having a piece of dirt in a carburettor messing with the jet

.

 

[MaximaGuy]

Clean MAF and TB, replace plugs, replace air filter.
Failing coils are also a suspect, BTW Nissan makes POS vehicles.
This is a company that couldn't make coils right for their maximas and wouldn't do a recall - forever I wouldn't be their customer.