Mazda 3 2005 : Idling/Staling debugging

[allaire]

Hi guys, I know this is a common issue and I've read multiple topics about rough idling/staling problems with the 3. But now I'm running out of ideas, so I need your suggestions.

Things I did:
- Clean the Throttle body
- Clean MAF

The only obvious thing left from what I've seen on different forums is changing the purge solenoid valve, here's the full story:

During winter, my car was having really rough idle (rpm jumping really bad) at red lights and was also staling from time to time. I cleaned the throttle body and it stopped (yey).

Since that, my car have not had similar heavy idling/staling problems, though it still has a bit rough idling (just a bit shaky) at red light.

But, last week my car staled twice, one time after I braked really fast and gave some gas right after, and the other time (like 5 minutes after) when I was going really slow in the parking (No CEL on both). Since that day, my car have not staled again. As good measure, I cleaned the MAF (recommendations from other posts).

Curious, I've then performed various tests to see what could cause staling. One thing I noticied, is when I'm idle, if I give a good tap on the gas pedal and brake right after, my car sometimes (not always) goes crazy, RPM jumping, car wants to stal (dash lights flash). If I touch the gas pedal again, it mostly stop. It's almost like if something was stuck, messing up the gas/air ratio... Could that be the Solenoid valve?

Other notes:
- Couple times during winter, when I started my car with my remote starter, the car was returning a CEL, but disapeared by itself on next ignition.
- Maybe 3-4 days before my car staled twice, I received a CEL (no idea what it was). Thinking it was just a false positive, I restarted the ECU, no CEL since even when my car staled twice.
- I've not noticed any particular issues when I start my car or after fueling.
- I changed my spark plugs this month and noticed some oils (not much) around them, saw it was probly a leaky valve cover gasket (not changed yet).

So, could that be caused by my purge solenoid valve? Maybe related to spark plugs?

Thank you !

Car spec:
Mazda 3 2005
Automatic
110k km

[cwp_sedan]

It is most likely not the PSV.

You need to get the CELs checked otherwise without them you will have no idea what is throwing the code. We won't be able to help you much either.


Have you thought about checking the battery/charging system and cables?

[allaire]

It is most likely not the PSV.
You need to get the CELs checked otherwise without them you will have no idea what is throwing the code. We won't be able to help you much either.


Yeah, I just bought a OBDII scanner, should be here in a couple days... Though I don't think I'll be able to see old CELs since I restarted ECU?

Battery is brand new, cables are clean from what I can see!

Thank you.

[cwp_sedan]

Yeah, I just bought a OBDII scanner, should be here in a couple days... Though I don't think I'll be able to see old CELs since I restarted ECU?

Battery is brand new, cables are clean from what I can see!

Thank you.


No you won't. Once they are gone you shouldn't be able to see them.


Did you start having problems before, during or after the battery was changed?

[peterm15]

There is another thread of a member having rpm jumps. Mazda has not figured out the problem but the symptoms ( break then gas rpm jump)seems similar.
I'm on tapatalk so I can't find it. But it may be a thread you want to follow.

[Wes08M3]

Like others have said, can't say for sure it's the PSV but if you'd like to rule it out, there's a procedure you can follow from the repair manual (which you can find on here, if you don't already have it) to test the PSV. It's fairly simple to do.

However, if you test it and it fails, it doesn't mean the PSV is bad for sure. A technician at Mazda told me that often its not the PSV itself, but the wiring harness breaks and causes the PSV to malfunction with no check engine light. So that's a lot more troublesome to fix. Anyway, you can test it to try and rule it out or try and replace it if the test fails. I'd link the owners manual for you but it doesn't work on my iPad.

[allaire]

Hmm, looks like you guys are not sold about the idea that the PSV might be the cause. I guess I'll just wait to catch another CEL... Weird thing is when I staled couple days ago, no CELs were returned...

[allaire]

No you won't. Once they are gone you shouldn't be able to see them.
Did you start having problems before, during or after the battery was changed?

I changed it during winter, same time I cleaned up my TB! So my last two stals were with the new battery!

[Wes08M3]

Hmm, looks like you guys are not sold about the idea that the PSV might be the cause. I guess I'll just wait to catch another CEL... Weird thing is when I staled couple days ago, no CELs were returned...

If the PSV isn't working it generally doesn't throw a CEL. Like I said, if you really want to know, test it!

Are you sure you have the correct battery in the car?

[allaire]

Is this what you're talking about: http://www.thaimazda3.com/svmanual/esicont/en/srvc/html/B3E011618740W03.html

Yea, pretty sure it's the right battery from my car, it fits perfectly, I told the guy at Canadian tire my car brand and year and gave some motormaster to me, lol.

Thanks!

[allaire]

If the PSV isn't working it generally doesn't throw a CEL. Like I said, if you really want to know, test it!

Are you sure you have the correct battery in the car?

Is this the test you're talking about? http://www.thaimazda3.com/svmanual/esicont/en/srvc/html/B3E011618740W03.html

Yeah, the battery is a Motormaster from canadian tire, told the guy My car and year, fits perfectly.

THanks