Low Vacuum, Cant find any leaks.... HELP.

[Cherokee]

Ok i hope I'm not asking the same question that someone else has asked. I have an intake vacuum problem, rough idle, and poor low rpm power. Sometimes it runs fine, but it is becoming more often than not that its just barely staying running at idle or i have to restart my car every time i come to a stop. I have tested my intake vacuum and its showing around 12 inches at idle. Spec is 17 - 19 in of vacuum. After i found that out I hooked up a smoke machine until smoke was pouring out the air filter. With no other leaks that I could see. Anyone have any ideas? I'm stumped.

 

[2GFWDbeast]

could be bad iac, tps, or idle switch.

 

[Cory-CR]

Keep in mind his car is a 420A motor, not a 4G63.

I'm not very familiar with those, just wanted to make sure that fact was pointed out.

 

[miguelmcv]

sounds more like an ICS

 

[2GFWDbeast]

im pretty sure those motors have it 2 of the things i listed are on the throttle body