Missing Hose near air intake?

[sjo]

Hi guys,
I'm very new to finding my way around under the hood, so i'm hoping one of the experts can help me. I have a 2000 classic 4L. I have a port on what i believe is the intake manifold, directly below the throttle body, which does not have a hose attached to it. If I put my thumb over it, the engine stalls. I assume that there should be a hose on this running somewhere, but where does it go? A picture is worth a thousand words, so hopefully the attached picture clarifies what I'm talking about. As you can see there are three ports, but the one on the far left is wide open. Any help is greatly appreciated.
Cheers
-Sam

[sjo]

Thanks to Mudderoy for showing me the ropes re: posting pics. Here is what was talking about ...

http://i1225.photobucket.com/albums/ee386/soliver1973/Jeep/JeepMissingHose.jpg

[xj4life2]

Sounds like it could be the MAP sensor line, it should run back to the firewall to the sensor itself. If I could see a pic I could positively identify it

[Mudderoy]

Sounds like it could be the MAP sensor line, it should run back to the firewall to the sensor itself. If I could see a pic I could positively identify it

This is a 2000 (97+) the MAP is on the throttle body isn't it?

[Mudderoy]

Get a rubber cap, yours fell off...

:link: (http://www.cherokeeforum.com/f2/vacuum-hoses-2000-intake-manifold-49696/)

[sjo]

Hmmm ... last night I put my finger over that hole and it caused the engine to stall. I'll try again - if it's supposed to be capped, but capping it causes the engine to stall, any ideas?

[xj4life2]

This is a 2000 (97+) the MAP is on the throttle body isn't it?

your right had the year wrong, and your also right about the cap at least according to my emissions diagram forthat vehicle.

[4.3LXJ]

Hmmm ... last night I put my finger over that hole and it caused the engine to stall. I'll try again - if it's supposed to be capped, but capping it causes the engine to stall, any ideas?

I'm not real familiar with the 2000, but in principle, you are sucking air into the intake past the throttle body and idle air controller. Normally, what you want is for the IAC to be what allows the air to go in during idle. It regulates the amount of air going in so that you get a constant rpm even when the transmission or power steering is engaged. So, what I would advise right now is cap it before you start it. Then start it and see if it will idle normally. It might be too much of a shock for the IAC to compensate for a sudden shut down of all air. If it works right, good. If not, we will take you through the next step.

[jccatt]

I can have a look at my 99 and take some pics.

[Mudderoy]

Hmmm ... last night I put my finger over that hole and it caused the engine to stall. I'll try again - if it's supposed to be capped, but capping it causes the engine to stall, any ideas?

Cap it then start it. That's a big open hole on your engine vacuum system. Ummm you didn't do something else recently to make it run did you? A modification because it wouldn't run correctly? If so that mod may be what is causing it to stall when you cover that open hole.

I'm betting it will run fine if you cover and start though.

[sjo]

I capped it and it started. Must have been the change in vacuum that caused it to stall when I put my finger over the hole. Thanks for all your help.

[gary63]

I have a2000 it is not here but when it gets back I will check it out if it has a cap you will be ok if it have something als I will lot you know.