Went out to start my jeep this morning to discover that it's missing pretty bad. 1 or maybe two cylinders. I driver it daily and as of yesterday she was running great. It's been raining since yesterday. My question is this. Are there any sensors that can go bad and cause a misfire? My guess an I have to wait till after work is that my brand new ignition components are bad "let in water" and I need to replace them. I just want to cover everything before I toss money at her. It idles rough, tap the gas, the rpms drop. If you ease into the gas the rpms will rise but you can still feel the miss. I do smell gas out the exhaust pipe. All vacuum lines including the map are connected.

 

I just got home and I'm uploading a video to youtube now. Here's what I've noticed now that it's light out. With the map sensor plugged in, she stumbles and dies as soon as you gas her. Black smoke comes out the tail pipe. When you unplug the map sensor *electrical plug* She idles up to 2k then dies, but does NOT misfire. It's like you're giving her gas, nice clean rev.

 

Video. http://youtu.be/mqRrHiK58NM

Can they just go bad overnight? No warning at all.

 

Yes, as they are electrical components.

 

The map sensor seams to be working, black smoke out the exaust i'm thinking O2 sensor.

 

Just to be sure, feel for vacuum with your finger on the line unplugged, at the Map. As I guess you might know, if the map isn't getting vacuum, (line plugged, cracked), it will run rich. Easy enough to be sure.

 

A bad O2 sensor won't make it run pig-rich and miss. The ECU goes into a default/predetermined mixture mode when an O2 sensor fails.

 

Had the same problem and it was a small hole in the vacuum line going to the map sensor.

 

check the plug that the MAP line goes into at the back of the throttle body it can also crack and leak

 

akita8 and highmileage offer some good advice. A slight to medium leak in that hose could cause your problem. Unplugging the MAP just floods the crap out of it and it dies quickly. I wouldn't overlook this.

 

I'm getting vacuum. That was the first thing I checked. I have to replace the electrical connector. The ground keeps wiggling out of the connector. I also have a new map sensor as well. Wish me luck!

 

Another video. http://youtu.be/v65ACWaOIF4

Another thing as well. After the jeep is warm, and you have the CTS plugged in. The jeep will not start. It will crank and crank, and you will smell fuel. Unplug the sensor, and she'll fire right up. I've never heard of a CTS causing a no start.

 

Did you ever do the sensor ground test in the beginning of my TPS write-up?

 

Yes, and the grounds are still testing out fine. I re tested today after I got home.

 

Have you tested the CTS?