[wdwisser]

Hello All... I have a 2012 Malibu with a EcoTech that runs when I have the plastic cover on the engine but when I take it off it stumbles and stalls and sometimes backfires. I'm totally baffled why this is occurring as I would think that has nothing, really, to do with the engine running properly as there is no electronics on it that I can see. I did leave the MF air sensor plugged in when I removed the cover (left the flexible hose that has that sensor). I thought that maybe it needed that to run properly.

Any help to figure out why this occurs as I cannot even check things are running unless everything is together.

Thanks,
Bill

 

[Jothro96]

My guess: the plastic cover has the intake tube attached, which the MAF is plugged into. Without the plastic cover on the engine, there's no airflow through the intake or across the MAF sensor, so the engine has no idea how to read how much air is coming in to adjust fuel trims and whatnot.
The 2.4 is oddly very sensitive to any intake changes, and will throw a CEL at alterations to the MAF position/intake tube.
If you're looking to not have to deal with the big bulky engine cover, there's a few good posts on the forum of how to assemble a new intake that doesn't use the stock cover.

 

[wdwisser]

Well, I'll have to say if that is the fact of the matter that is a very odd design to do this as how to you work with anything on the engine then while running with this big plastic cover... totally dumb by the GM organization.

 

[DrivenDaily]

Unplug the MAF and try again.

 

[wdwisser]

I tried that as well, unplugging the MAF, and it does the same thing. It is just an odd thing that you must have something on there to have it run. It is running now so I will not continue this conversation but I do appreciate everyones input on this.

 

[DrivenDaily]

... so I will not continue this conversation ...

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