I suspect my Brake Power Booster is leaking. I have all the lines blocked off except the one to my booster, put the gauge on and it reads 16-17 in Hg at about 500ft over sea level.Slightly fluctuates with a drop or loss in idle. I beleive it should be somewhere around 20 should it not? So I pulled the hose off from the manifold to the booster and blocked it with my thumb seemed to have no effect. In theory if this was the issue that should have brought the vacuum up right?

 

I would think so IF that is the problem. OR just get a can of choke cleaner and spray the hose connections; if the idle stumbles then you know its leaking. That or build a pressure tester. I made one from a pipe cap, a 1/4" bulkhead fitting, a tee, 0-60 psi gauge, and a tire valve; works like a champ for diagnosing boost leaks in the charge system of my boosted 240sx.

 

Gotcha, just sprayed the connections, no major drops. Just randomly fluctuates a little bit. My idle seems a bit out of control after it sits for a while, gets kinda high. And I have the whole EGR system blocked off...any thoughts?

 

what year is it?

 

I'm not sure if the blocked EGR is related to this but I wouldn't think so; unless you didn't block it well and that's your leak...? I removed the EGR system on an 4 cylinder turbo project without any idle issues; but this was on a manual transmission car also not a Jeep. I'm not very seasoned on automatics; ya'll seem to have more idle issues than us 5 speed guys.