Here are the symptoms...this is a buddy's Maxima - currently at 80k.

While pulling into a driveway, or reversing slowly and then taking
your foot of the accelerator to tap the brakes, the car will
intermittently stall. Sometimes it is hard to get started again, i.e.
will start, but stall immediately. It doesn't happen at speeds over
30mph - and seems to only happen when the accelerator is released i.e.
either to coast or to brake.

Here are some data points.

1) I cleaned the throttle-body (it wasn't very dirty when I checked it
- I but I cleaned it anyway).

2) I Replaced PCV valve

3) I Checked air-filter (was clean)

4) I Checked basic operation of IACV - I had the car idling (at about
650-700 RPM - auto tranny) - set fan to high with A/C on - the idle
dipped and then climbed back up to about 750 and held steady.
Switched off A/C - idle dropped to 650 and stayed steady. (Repeated
this several times - could not get the car to stall).

5) He had a 60k service done at a dealer - new plugs, new fuel
filter... may have done radiator/tranny fluid changes - but I don't
think that is relevant for what is going on here.

6) He ran a bottle of techron through the fuel system.


The problem suddenly went away (after I did the above), but 8 months later, its back again... any suggestions? The CEL is not lit and there are no hidden codes stored.

Any ideas or thoughts.. the stalling is so intermittent that I can't duplicate it very often (it only happened once with me)...

Nirav

 

back-to-the-top

 

:attention

 

Check hte vaccum lines. The vaccum lines are the 2 hoses from the MID PIPE. Once hose goes to the IACV and the other goes to the Front Vlack Cover. There is a third smaller hose, but I don't know hwere this leads to. Make sure they are nice and secure.

 

Will do... I won't have access to the car until this weekend - so I'll update you of progress at that time...

Meanwhile let me know if you can think of anything else that I should consider...

 

Are you SURE there are no codes? You should get at least a 55 to show no codes present. My MIL bulb was blown and couldn't get a reading until it was replaced, then I isolated the Engine Coolant Temp Sensor.

 

Yup - 05 05 is what I got when I checked the ECU for any errors.

 

More description of the symptoms that my buddy emailed me this morning...


"The car did stall on me yesterday and gave some trouble again this
morning.
It happens either when I am just cruising (20- 40) without my foot on
the accelerator or the brakes and then when I pressed the acc. then it
"stuttered". It also happened when I was at a stop sign and as soon
as I hit the accelerator it "stuttered". Also, as I was approaching
the stop sign and slowing down to 0 miles, it stalled after which it
stuttered as I mention above."

Does this information help any?

 

It might be ignition coils, not sure becuase i have never read about a problem like this.

 

This problem really is a wierd one... I think it could even be the MAF... but thats an expensive experiment... I'll poke around the vacuum lines and maybe try to ohm out each coil and see what I can find.