Rough Idle then Stall

[DavieGravy]

I did some searching, but didn't find the problem occurring for people under similar circumstances to mine. So here goes:

Rough idling occurs (worse when the engine fan is off.) If I put it in park, it'll eventually stall after the RPMs slowly and randomly fluctuate, then it will die out. I didn't experience stalling in drive.

2 weeks ago, I hosed off the engine and it was doing the same thing, just more severely. I think it was misfiring from water getting into forbidden places. Eventually the problem "cleared out" as the water dried up.

But now, it's happening again. And unlike then, the RPMs are now slowly fluctuating and it doesn't seem to be misfiring, just idling very rough.

I'm not sure if this is related, but yesterday evening, before this started happening, I noticed a fowl, urine-like smell coming from the engine bay that lasted for about 2 minutes and then went away. The kind of smell you get when letting the air out of your tires. Upon a quick and brief inspection, I found no fluid leaks or anything of that sort. The car ran fine after this, but I had only driven it on a 15 minute highway trip back home. I went on a half hour trip (each way) today. The problem started to happen on the way back.

But the rubber/urine-like smell leads me to believe there might be a blown vacuum hose. Is this possible?

Other possibilities I've considered are a bad battery or bad gas. My battery is definitely dying, but turnover during starting is generally fine if it isn't the first start of the day.

Any help with this would be greatly appreciated as car problems are very worrisome for me.

Thanks in advance.

[Subafreak]

With a urin smell, I'd make sure there isn't anything living in the air filter box, under the intake is a popular place for critters too.
Take a look around to see if you can find any nests. If there is a vacume leak you might be able to hear it , but look for chewed wires and hoses under the intake.

Got to start somewhere

[DavieGravy]

Thanks Subafreak, but I don't think that's the case here. In fact, my airfilter looks brand new. I gave a quick look over my engine today and didn't find any blown hoses. Not to say there isn't any, I just didn't find them.

The only abnormal things I noticed were that this plug was loose and that this pulley was wobbling a bit. Should it be? Do I neeed to tighten the nut up?

Sorry for the large file size of the pictures.

The car has been sitting in the driveway idlling for the past 20 minutes without issue. I don't get it.

[Subafreak]

Well a loose Mass Air Flow sensor plug could definitly make the car run bad, but it should also turn on the check engine lite.

A little wobble in the crank shaft pulley, may be due to the rubber wearing out or it could be loose, I'd at least check to make sure the bolt is tight, because it could destroy the end of the crank, and that would be bad.

[DavieGravy]

I tried to tighten it but the belt moves with it. How do I lock the pulley in place?

[Subafreak]

If it didn't move it probably tight, but to keep the pully from spinning while tighening you need to remove the rubber plug from the bell housing, (it's hiding under the intake tube) an lock a pry bar on one of the tork converter bolts.