NoOoOo!! CEL and wildly fluctuating RPMS!

[SilentJay]

The car started up fine this morning, but when I drove into the parking garage at work, I noticed the car was stuttering... then the CEL came on. Then I noticed the RPMs were flying between 1100 to 500, back and forth almost in a pulsing manner. I limped into a parking spot, making sure the car was backed in just in case I needed a tow. I smelled a tiny hint of burning, but didn't see any smoke when I popped the hood.

'07 with 18k on it. I have a CAI, but I had it running for a good 5 months with no issue. I hope to [insert religious diety here] that I don't have to remove the CAI when I bring it in... I'm going down to take another look in about an hour, check the MAF and such.

1) Anyone ever experience the same thing?

2) Thankfully (I think) I am about 3-4 blocks away from Westowne Mazda. Should I bring it there? Possibility of damage if I limp it there? Anyone I should talk to there?

Thanks!

[3GFX]

CHECK THE MAF!!! Could be a vacuum issue.

[midnightfxgt]

I would put money on it being your MAF Sensor!! The wires are super short, and thus put stress on them when you install a CAI. Are you throwing a CEL? If it is "MAF Sensor Voltage Low - P0102) then you can almost bet on it.

Check your MAF (the sensor in the CAI pipe) for wires that have come out. There may also be fractures in the wire that are hard to see.

Last thing you can do is clean out the MAF, but since this was out of the blue, my bet is on wiring.

-John

[SilentJay]

I went downstairs and checked the MAF and associated wires - they seem to be in, and there is a tiny tiny bit of give on the wire for movement, but nothing out of the ordinary. I'm in an underground parking lot, so light is a precious commodity, but from what I could see it looks ok... should I unscrew the MAF and check it like that?

I called westowne, but the service advisor was apparently busy. I left a message...

[3GFX]

I would tighten it again, then check ur gas cap as well. When you start the car see if you can hear a sucking sound anywhere because then you've got a vacuum issue in the system. Otherwise maybe a wet filter (loose filter?).

[SilentJay]

OK, i'm gonna head downstairs to take it off/check it, and tighten it again. i'll check the gas-cap, but would that make the RPMs jump up and down like that? The filter has been bone dry for days, but i'll check that too.

[SilentJay]

I found the problem. The middle MAF wire snapped out. I did a half-arsed soldering job, but I gotta take it in I guess.

[sauga_kid]

Glad you found the problem. Just curious, did you disconnect the wires from the battary box to give the MAF some slack? If so, I'm a little concerned that mine might snap too, is it necessary to the MAF wire extension mod if you're running the F5? Hope all works out for you SilentJay

[midnightfxgt]

I knew it! I had my middle wire snap too, but mine was running OK (probably since the Haltech manages my fuel) just a little jumpy on idle.

Sauga Kid - Where are some details on this mod? It sucks working on those wires, not much give.

[sauga_kid]

John, here's the link:

http://www.mazda3forums.com/index.php?topic=64661.0

[cwp_sedan]

John, here's the link:

http://www.mazda3forums.com/index.php?topic=64661.0

I remember reading this before. Too bad the guy did such a messy job. We need someone to make a plug n play application. Or something easy anyway.



Glad you found the issue fairly quickly.

[SilentJay]

I did a hack job of soldering the wire together long enough for me to get to Westowne Mazda, and let them look at it. Its now fixed, although I haven't had a chance to look at their handy-work yet.

Yeah, I guess over the months, there was too much tension on those two retaining clips attached to the battery box (battery box clips were snapped off when I picked up my car brand-new from MoT by the way), which forced it to break. One of the clips was already broken, but the second one was still there. Gonna break it off if it's still there later.

[midnightfxgt]

John, here's the link:

http://www.mazda3forums.com/index.php?topic=64661.0

I think I owe ya a beer for that one! I didnt know how to get those pins out. Mine was done quick and dirty to fix the problem. I will be taking them all out, and extending them now! :)

When you have your MAF out... CLEAN IT! Electrical contact cleaner, and just hose it down. May as well while your in there!

-John

[SilentJay]

:p I checked out my wiring. They only extended the one wire that had snapped. Anyone wanna extend my wires too? :D

[sauga_kid]

Hahaha, don't mention it, name the place and the time, Stella is the other girl in my life:chuckle


I think I owe ya a beer for that one! I didnt know how to get those pins out. Mine was done quick and dirty to fix the problem. I will be taking them all out, and extending them now! :)

When you have your MAF out... CLEAN IT! Electrical contact cleaner, and just hose it down. May as well while your in there!

-John