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it keeps stalling out

17K views 18 replies 10 participants last post by  2008mazda32.0l 
#1 ·
Hey there all my car keeps idling extremely low and stalling out when I'm stopped or stopping is this the egr valve? Or is there something else goin on here thanks
 
#2 ·
How does it start when after you fill up your gas tank? I had the same problems and it ended up being the purge control solenoid valve. Mazda replaced it under warranty.
 
#6 ·
I'm not getting a cel ill start the car it'll idle fine then eventually start studdering and bogging down then eventually stall out and sometimes when I stop the rpms just drop and it shuts off. The only reason I tthink its the egr is that mazda told me it needed to be replaced before and I thought the dealership was just trying to choke money out of me.. So I never even looked at it
 
#8 ·
A lot of stupid stuff can go wrong and never throw a code, check you air filter, spark plugs, and make sure their is no oil on the spark plug boots. Run some good injector cleaner through it to clean your lines, and make sure their is no water in the system. All of these are $5 fixes, no problem.
 
#10 ·
So I checked my cai and the coupling was lose from the throttle body so I tightened it and now it won't stall out but its still studdering and idling extremely low
 
#13 ·
What do you mean by studdering? specific examples would be nice, a video would be perfect.

Low idle is associated with vacuum lose, also the purge valve which is a common issue. I have also founf that failing throttle body solenoids can cause issues with low idles.

IF you can get some active readings on your idle vacuum would be nice, aswell as maf voltage, tps ect.

we do not have an IAC so that is no cause of worry.

Check your spark plugs see if they are gapped properly. Another thing you can check is if the studdering is a miss fire, or if the car isn't firing on all 4. go and unplug the coilpacks one by one plugging them back in before moving onto the next. same can be done with fuel injectors. Although this is the extreme of things and should be done last.
 
#15 ·
I'm pretture sure in these cars taking a boot off while the car is running *can* send a surge of electric through the computer, and fry it. I've seen it happen before. Test the voltage with an actual multimeter to make sure all of the coils have roughly equal resistance. Set the meter to Ohms. But fyi a misfire would throw a check engine light (unless the light is blown). Even a small miss would give you a check engine light.
 
#16 ·
I have yet to see ECU failure due to pulling a plug. This is an accepted form of diagnoses, This is from several trusted mechanics that i know.

the ecu will not necessarily throw a code due to a slight missfire, I have had my engine before running very rough at idle with a close spark plug gap cause all types of issues and not one code was thrown. Granted the moment I pulled the plug out of the coil it threw a code, but the engine didn't act any different when doing so.
 
#17 ·
I work at an Autozone and have tested ecu's that this has happened too... OLDER cars that was a fine way to do it, anything that the plug should be gapped at above like .040 you shouldn't do that too. The coils put out too much power to test them that way. Ask anyone that has been recently ASE certified (not the recertification test)
 
#18 ·
Since you found that the coupling was loose on the CAI (and causing a leak of air charge), have you just tried resetting the ECU and seeing if it straightens the idle back out after a bit of driving? It will drive rough for the first little bit and have a bouncy idle, but then it should smooth out and go back to normal. Just unhook the negative terminal of the battery for a few minutes then reconnect it and go.
 
#19 ·
So my friends its no longer idling low or stalling out and I've done absolutely nothing but mess with the coupling from the cai to the throttle body so ima guess the loose connection was doing it
 
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