To start off i have owned this jeep for a little less than a year and it mostly runs fine. When i start it up after the engine is cold it hesitates when I try and accelerate. If its cold outside the engine will usually die after the hesitation. I also have been getting a weird RPM drop when im at around 2000 RPM. It will drop down to idle, around 1500 rpm and then it will usually jump back up after a couple seconds. It starts doing this around 30 mph. My jeep also does not blow air out of any of the vents except the defrosters by my windshield. What would this be? There is a hose that is broken in front of my air intake. I am not sure what type of hose it is. It comes from the left side of the front if you are facing the jeep and it goes back toward the block somewhere. I have done my research about the problems but i have no idea where to start. Any help would be greatly appreciated! Thank you in advance.

 

Might start by following Cruiser54's instructions on testing and adjusting the throttle position sensor, refreshing the grounds (if you haven't already) and checking your fuel pressure.

The defrost-only thing, there's probably a vacuum line gone bad to the HVAC controls, "defrost" is the default position. If it's a big enough vacuum leak that might be adding to the hesitation problem too.

 

Can you tell me where the HVAC control vacuum line is? I tried to look for any broken vacuum lines but i didnt really know what i was looking for..

 

Judging from the drawing I found, it routes from the HVAC controls up to the vacuum reserve tank in front of the Jeep. I believe the reserve tank is behind the front bumper. I wonder if that is the line you found disconnected?

 

There is a vacuum storage bottle in the passenger side of the front bumper. The vacuum lines run from there, past the battery and up to the firewall near the blower motor. Common for them to break causing your issue.

Do the ground refreshing, sensor ground test, and TPS adjustment to address your hesitation issue.

Have YOU ever replaced the plugs, wires, cap and rotor?

 

I checked for the vacuum canister and its not there? I looked up a diagram and im fairly sure i didnt miss it.. I have an aftermarket bumper. Could the canister be relocated? Are all the placements the same on all the years? I checked my plugs a couple months ago but i havent replaced anything that involves them. Also PO did A/C delete. If that means anything for the canister..

 

They might have put one up near the coolant bottle. Take a look.

 

I found that one. I saw two lines coming off of it going to the right. neither of them were cracked either.

 

Is that canister the evap canister?