The hose outlined in this picture on my car, I found broke down where it starts to come up through the intake manifold. I was curios what exactly is it for and what is it that it connects to below?

 

PCV Valve hose.


There's a little black box unerneath the intake manifold where it goes to.

 

ok, Im having problems with the idle on my car bouncing from 1k to 1400ish. would that hose cause that problem?

 

That hose could cause the idle problem, unless you have some other vaccuum leak or air in your cooling system.

 

well after awhile itll throw a code that scanned saying idle air control system. could that still be air in cooling system or is it most likely a vacuum?

 

Could any of the above, but if that hose is broken, that's likely the issue unless there's additional problems.

 

well for a quick fix i plugged em and its still doing it but ill have the hose replaced when i get paid and see what that does. as far as air in the rad how (if there is any) can i get that out?

 

the hose is attached to a valve on top of the black box slomofo mentioned, the valve could be clogged, fairly easy to check and cheap to replace. if you take it off shake it and listen for clicks, if it doesn't then its bad or needs to be cleaned

 

Take the hose off from the manifold and cap it and see if it changes anything, you can remove the whole PCV setup and it shouldnt do anything as long as you cap it on the manifold. All it does is send blowby back into the engine and the PCV is a check valve.

 

I replaced the hose. and made sure the pcv was good. Still getting a weird idle. nrmally itll bounce from 1k-1800. after he check engine light comes pn it starts to bounce realy fast from like 12-1400, and wen u otuch the gas pedal car with jerk forward hard.

I went over eveything couldnt find anyore broken or missing lines any ideas?

 

Sounds like your IACV (Idle Air Control Valve) is malfunctioning, maladjusted, or dirty. there is a little screen in there that gets clogged with carbon after a while. The valve is like a little computer contolled throttle that kicks in to compensate for engine load variations caused by accessories (alternator, A/C compressor, power steering etc.) Try turning the steering wheel when stopped. This should trigger the IACV to boost the RPM's a little. You probably need to remove, disassemble and clean the IACV or replace it.

I you look in the photo its the aluminium and black plastic thing bolted to the rear of th intake manifold (very top of the pic). 2 bolts, 2 hoses, 1 electrical connector to remove I believe

 

take intake off and plug the throttle body with your hand, does car die/sputter and almost die? if no, vacuum leak is causing surging idle. Might wanna clean up your iacv too (on back of intake mani, 2 12mm bolts) with some carb cleaner.

 

the IACV is new, at most 2 months old. Ill try plugging TB.

 

Spray some engine starting fluid around where you suspect a vacuum leak. Try plugging vacuum hoses coming from accessories like the brake booster to eliminate leaks as a test.

 

ya ima go out in the morning an start searching for a vacuum leak of some sort.