Low idle problems
Herp Derp Jerp

Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
What's the difference between a pcv and a ccv? Because when I look at autozone the thing I can find to stick in those hoses is called a pcv, will that work or should I grab some from the junk yard?
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Renix Vacuum Harnesses
The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7151367_0269070623
The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK-715-1366.
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7151366_0269070622
The tube from the rear of the valve cover to the intake manifold is part number 715-1365.
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7151365_0066877355
Revised 09-11-2012
The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7151367_0269070623
The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK-715-1366.
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7151366_0269070622
The tube from the rear of the valve cover to the intake manifold is part number 715-1365.
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7151365_0066877355
Revised 09-11-2012
Renix Vacuum Harnesses
The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367
http://www.napaonline.com/Catalog/Ca...367_0269070623
The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK-715-1366.
http://www.napaonline.com/Catalog/Ca...366_0269070622
The tube from the rear of the valve cover to the intake manifold is part number 715-1365.
http://www.napaonline.com/Catalog/Ca...365_0066877355
Revised 09-11-2012
The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367
http://www.napaonline.com/Catalog/Ca...367_0269070623
The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK-715-1366.
http://www.napaonline.com/Catalog/Ca...366_0269070622
The tube from the rear of the valve cover to the intake manifold is part number 715-1365.
http://www.napaonline.com/Catalog/Ca...365_0066877355
Revised 09-11-2012
Herp Derp Jerp

Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Positive Crankcase Ventilation: Valve-operated release of crankcase pressure from blowby, engine inhales gasses.
Closed Crankcase Ventilation (called this to differentiate from the draft tubes of old): Fresh air always running through valve covers, engine inhales air and gasses. No valves.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
AutoZone is a bunch of idiots. Though you'll frequently find the CCV fittings and elbows incorrectly called PCV Valves in MANY parts databases
Positive Crankcase Ventilation: Valve-operated release of crankcase pressure from blowby, engine inhales gasses.
Closed Crankcase Ventilation (called this to differentiate from the draft tubes of old): Fresh air always running through valve covers, engine inhales air and gasses. No valves.
Positive Crankcase Ventilation: Valve-operated release of crankcase pressure from blowby, engine inhales gasses.
Closed Crankcase Ventilation (called this to differentiate from the draft tubes of old): Fresh air always running through valve covers, engine inhales air and gasses. No valves.
AutoZone is a bunch of idiots. Though you'll frequently find the CCV fittings and elbows incorrectly called PCV Valves in MANY parts databases
Positive Crankcase Ventilation: Valve-operated release of crankcase pressure from blowby, engine inhales gasses.
Closed Crankcase Ventilation (called this to differentiate from the draft tubes of old): Fresh air always running through valve covers, engine inhales air and gasses. No valves.
So the system is not there to just take excess air out of the valve cover area (valve cover area?? Yea I don't know what I'm taking about) it is there to put clean air INTO the "valve cover area"?
Herp Derp Jerp

Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
It does both. It recovers blowby and oil fumes as well as providing some of the fresh air for the engine. Particularly important when the throttle plate is shut.
Also I have a 1988 xj, but the motor is out of a 1992 xj, can't remember which valve cover I used though, is this going to cause any compatibility issues?
Junior Member
Joined: Feb 2013
Posts: 56
Likes: 0
From: In the Back Woods
Year: 1998
Model: Cherokee
Engine: 4.0L "Power Tech HO"
Assuming your IAC is in good working order. Make sure TPS is good. Check fuel pressure and make sure its 50 psi. Also check the injectors to make sure you dont have a weak one-also o-rings on the injectors-Good luck
Last edited by KCXJKID; Feb 6, 2013 at 01:47 AM.



