I have a 2000 Mazda 323F (some say it is Protégé but not sure) AT 1.6L (at 128K km).
It runs smooth, accelerates great and shifts nice on most occasions.

But there are times after running for a while, it stalls at intersections and/or when coming to a stop.
I read some forums and also one of our own: Car Stalling (but I think it is not related).

To make the story short, my research points me to the ATF level, checked it and it is fine. Kinda overfill though based on the markings but not so much.

Then it points me to checking the EGR (I don't know if my car have that, I will check it tomorrow - I read that some 1.6 AT have no EGR) and more research points me to the Catalytic converter.

Before I go nuts on what to do first, I remembered you guys.
So please, if anyone of you had experienced this in your Mazda's please share your thoughts.

  • Does it only happen after the engine has reached operational temperature (warmed up)?
    – race fever
    Mar 30, 2016 at 13:28
  • Are there any codes? What are the fuel trims like?
    – Zaid
    Mar 30, 2016 at 15:51
  • @racefever No. It happens even at start up.
    – L42
    Mar 31, 2016 at 0:32
  • @Zaid No codes flashing when the car rpms drop to 100 but I see the battery lit for awhile.
    – L42
    Mar 31, 2016 at 0:34
  • You could have a bad battery/alternator. Do you have a multimeter to test with?
    – race fever
    Mar 31, 2016 at 0:34

1 Answer 1


I suspect that this is caused by one of two things although it could be a few more. It is most likely a sticky ISV. The ISV or Idle Stabilization Valve is responsible for allowing just enough air through the engine to keep it running when the throttle pedal is being pressed. If this is faulty, the car will run perfectly until you take your foot off the throttle. If you can locate it in your engine, you can attempt to clean it with some fuel system cleaning spray available cheaply from most motorfactors.

If the ISV is working fine then my money would be on a failed temperature sensor. This could be failing to tell the cars ECU (engine control unit) that the engine is hot. A hot engine requires a difference mixture of fuel to continue to run correctly so if this is getting a false temperature reading, it could have problems determining the right amount of fuel to supply.

If it's neither of these things then it could conceivably be a vacuum leak caused by a split pipe or perished rubber seal somewhere on the inlet side of the fuel system.

If cleaning the ISV doesn't have the desired affect, have someone with a fault code reader scan the car for faults. This will take all of the guesswork out of diagnosing the fault as they ought to tell you exactly where the problem lies.

  • Yeah, the mechanic also mentioned about the ISV. Now, we will be checking the battery, alternators, vacuum leaks as you said it and yeah the pipes that supplies the fuel.
    – L42
    Mar 31, 2016 at 0:35
  • Alternator and battery are ok, we will now attempt cleaning the ISV.
    – L42
    Apr 4, 2016 at 7:12
  • Steve no problem on ISV as well. We cleaned it and I still encounter it when I accelerate and then come into a sudden stop or turn to intersections. I'm going to check on the temp sensor but have no idea where to find it. The manual doesn't seem to mention it either. Please help.
    – L42
    Apr 18, 2016 at 9:38
  • Btw, we will be checking vacuum leaks as well as you've included in the post
    – L42
    Apr 18, 2016 at 9:59
  • It turns out it is really just cleaning the ISV and changing the ATF fluid. No vacuum leaks.
    – L42
    Apr 26, 2016 at 7:52

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