Earlier this afternoon was the last time I drove my car. To the exact second I parked it and shut it off, it was running fine. Later in the evening, I removed the vacuum hose that goes from the passengers side of the throttlebody to the charcoal canister to put braided steel sleeving on it. I made sure it had no leaks and reinstalled it.

Now, About an and a half ago I just went out to start my car to go grab a pizaa for the midnight Shake N' Bake and as soon as I started it, it stalled. I tried starting it again and the second I lifted my foot off the pedal, the engine rapidly dropped down (You know how normally it winds down slowly but if you are say adjusting the IAC and have it disconnected it will wind down rapidly), stumbled at 400 RPM, then cut off.

I got under the hood making sure nothing was awry in case I had forgot to connect something or knocked something loose earlier. Everything looked fine. The only thing I unhooked when putting the hose back in was the air snorkel so I could fit it under the throttlebody and the the TPS. But I made sure the snorkel was snug back on the throttlebody and the throttle position sensor was plugged back up. I even verified this when I was checking under the hood. I did check and make sure the IAC had not been knocked loose and it was all plugged up.

The car did this 5 times in a row before I gave up and called for delivery. If you hold the gas down it will rev normally. But as soon as you let off the gas the tach plummets and struggles at anywhere from 100 - 400 RPM for a few seconds. A few pops can be heard from the cylinders firing at a very slow pace, then it shuts off. It's like It's not getting any air with the throttle closed.

Did I forget to do something/knock something out of whack, or did a part coincidentally decide to fail after I turned the car off earlier today (IAC)?

 

I just went outside to check the engine again and scan codes. The ECM spit out the normal codes 24 and 44 (Needs a heated O2 sensor and still investigating the VSS). I then went back under the hood to check the engine thoroughly and I discovered that underneath the throttlebody the bottom lip of the snorkel had pushed up into the throttlebody opening so when I tightened the clamp this left a pretty big hole at the bottom snorkel so a portion of the air intake was allowed to bypass the filters.

I promptly fixed this but how would this cause the engine to behave as it was? This goof was in the very beginning path of incoming air so It's not like it caused a vacuum leak. Or, was this bypass throwing off the MAF since not all incoming air was going through the MAF anymore and causing the car to stall? I haven't tried starting it yet because It's 1:40 and the neighbors tend to get grouchy. We will find out for sure tomorrow.

 

Right after I hit the 'Submit" button, I figured F it and went out to start the car. It fired right up and held at 1500 RPM for a few seconds, which is how it normally starts up so It's fixed since it didn't immediately stall out.

Wow, that was a quick fix lol. I suspect that the incoming air allowed to bypass the MAF gave an extremely lean fuel mixture allowing it stall? I'm not concerned about anything foul being sucked into my engine since it was only run for a total of 60 seconds sitting parked in clean air.

I assume this an omen and attribute it to faith, though. Since when I went to get the pizza, I was a little buzzed. I do not advocate intoxicated driving, but the pizza hut is literally within walking distance from my house so I figured it wouldn't hurt anything with it being so late and so close. OK, I've learned my lesson(s).

 

Nice... Good info to share. I'm sure I'd be in the mood for pizza and beer after going through that. I hate how stupid lil snesors and modules can throw your whole engine off... that is exactly why I ditched my computer and went with a carb! lol Glad you got it running.