Is something supposed to be hook up to this?
Not sure if this is the right area to put this, but here goes:
The little valve (not sure what else to call it) second from the right- should something be hooked up to this? Is so, what is it?
Oh, this is an 87 if that matters..
Thanks in advance.
The little valve (not sure what else to call it) second from the right- should something be hooked up to this? Is so, what is it?
Oh, this is an 87 if that matters..
Thanks in advance.
Senior Member
Joined: Jul 2012
Posts: 860
Likes: 0
From: middleburg fl
Year: 1998
Model: Cherokee
Engine: 4.0
its where you would install a pressure gauge to check fuel pressure. but it is a test port not something that stays attached all the time
wait are you talking about the open hole on that black piece next to the halfass hose repair
wait are you talking about the open hole on that black piece next to the halfass hose repair
Last edited by kennzz05; Jun 16, 2013 at 02:14 AM.
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CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
The "intake manifold" is where the pistons suck air in to the engine through the air cleaner. The "TB" (throttle body) is hooked to your foot on the throttle.
The manifold "vacuum" is on the engine side of the plate you control with your foot. "Up-stream" of that plate, is normal air pressure. ("vacuum is really just pressure less then we all live in here, about 14.7 lbs/sq.ft).
So anyway, you don't want any "vacuum leaks". (stuff not connected. No intake manifold/open ports/). nothing disconnected, hissing/sucking on the intake manifold, plug or cap any that you can. Of those that really matter are the one to the Fuel pressure regulator on the fuel rail. One near your PIC goes to the CCV valve on the rearward end of the valve cover. (also)
One of the big tubes, the forward one, holds the vent from the front of the valve cover, that goes to the air cleaner. (Mine is different, has clover). Right there that has another "holder/fitting" (rear of that),which on my 90 does nothing, just is there empty.
Like lentish says, that top Elbow off that fitting with two others goes to the FPR.
The manifold "vacuum" is on the engine side of the plate you control with your foot. "Up-stream" of that plate, is normal air pressure. ("vacuum is really just pressure less then we all live in here, about 14.7 lbs/sq.ft).
So anyway, you don't want any "vacuum leaks". (stuff not connected. No intake manifold/open ports/). nothing disconnected, hissing/sucking on the intake manifold, plug or cap any that you can. Of those that really matter are the one to the Fuel pressure regulator on the fuel rail. One near your PIC goes to the CCV valve on the rearward end of the valve cover. (also)
One of the big tubes, the forward one, holds the vent from the front of the valve cover, that goes to the air cleaner. (Mine is different, has clover). Right there that has another "holder/fitting" (rear of that),which on my 90 does nothing, just is there empty.
Like lentish says, that top Elbow off that fitting with two others goes to the FPR.
Last edited by DFlintstone; Jun 16, 2013 at 04:19 AM. Reason: I eddited allot.
Seasoned Member
Joined: Jan 2011
Posts: 303
Likes: 4
From: Austin
Year: 1987
Model: Wagoneer
Engine: 4.0
If you want all new vacuum harnesses, the 3 part numbers you will need are here (I've only ever found them at Napa : https://www.cherokeeforum.com/showthread.php?p=1228823
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
The stock injectors from 87 to 90 are truly crap btw.
https://www.cherokeeforum.com/f2/199...r-swap-163105/
https://www.cherokeeforum.com/f2/199...r-swap-163105/
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors



