- Joined
- March 4, 2007
- Messages
- 26,320
- Reaction score
- 122
- City, State
- anaheim hills,california
- Year, Model & Trim Level
- 95 ranger 4x4/ 91 X 4x4
...This is for all the 91-94 Explorer/Ranger owners looking for answers on their Stock Air Box setup, Filter options, adding a CAI (Cold Air Intake), and for those who want to return their Intake Air System back to stock and don't know where to begin....
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...The 91-94 Explorers/Rangers have what is called a Thermostatic Air Cleaner, Intake Air System and is an important part of your Emissions system...If you do not have this in proper working order, you will fail both the Visual, and your Emissions Test....
Thermostatic Air Cleaner
The below info can be found here and is used just to describe the following...
http://www.wivip.com/index.html?te_idletest.html
The Thermostatic Air Cleaner System is an early emissions control device that was designed to deliver temperature-regulated air to the intake manifold such as warm air for cold engine conditions and cool air for engines at normal operating condition. Thermostatic Air Cleaner systems usually consist of an enclosed air filter housing, with an air intake snorkel containing a thermostatic control valve. This thermostatic control valve controls whether cool air or warmed air enters the intake manifold through a vacuum signal. Later models have used electrically activated thermostatic control valves. After the engine has reached normal operating temperature, the thermostatic air control valve returns to a position to allow cool air to enter the intake manifold for normal engine operation.
Thermostatic Air Cleaner items checked:
1. Exhaust shroud is missing or not secured properly.
2. Heat riser tube, cold air duct, air cleaner cover, plugs, flexible material between air cleaner and vacuum motor, is missing, broken, plugged, taped or disconnected.
3. Vacuum lines or hoses are missing, broken, plugged, taped or disconnected.
4. Air cleaner is missing or "unsealed" for a Pulse Air type system. Wing nut(s) missing.
5. Vacuum motor port is not properly sealed (if dual snorkel).
These pictures show how your vacuum lines properly hook up and also the locations of it's parts...
...This is where your 2 vacuum lines connect at the top, rear of your Stock air box lid..(The bottom half of your airbox is mounted on top of the right front fender) This lid fits on top of that piece...
...This is a pic of the underside of your stock air box lid...Note the vacuum port on this side...Nothing connects to this...(But on the top side of this port is where the vacuum hose for the thermostatic control valve connects)
...This picture shows the proper placement of your vacuum hoses...
...And last but not least, this is your Thermostatic Control Valve located in your Cold Air Intake duct...It is located behind the passenger headlight and most people can only see the vacuum hose heading down to it...Be sure this hose is connected...
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Stock Air Filter Options
...In this picture the top filter is an STP filter which comes designed with a ridge that keeps all the individual pleats from closing together...The bottom filter is a Fram air filter...I have found that these tend to close up and clog when they are in a real dirty/dusty environment...This shows the bottom, pleat side of the filter...
...This is the top side of your air filter...The fresh air is drawn in from the bottom of the filter, througt this top side of the filter, to your MAF, on through the duct, and to your throttle body...(Again, notice the pleat separation from the STP air filter)
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Optional Cold Air Intake (CAI) Upgrade
...There are several models to choose from...K&N and KKM, are 2 of the most common to be found on Explorers...I have the KKM that was designed for our motors...Here is a link to their site... http://www.kustomz.com/054094.html
They have installation info so, here is a pic of my setup...The KKM filter pretty much sits just above the bottom half of the stock airbox and attaches to the existing tube...It takes a whole 10 minutes for the swap to stock for the smog test..:biggthump (Note the capped off vacuum line from the motor, the one with the bolt in it)
Note:...If you live in California, these will not pass Smog
Is the True-Rev Induction kit emissions legal in my area?
The True-Rev Induction Kit is designed for competition use and though it does not eliminate any required emissions devices, it does not carry any emissions exemption certificates. The bottom line is check with your state testing stations for guidelines on engine modifications. Our Kits are not C.A.R.B. certified.
...And here is a link for C.A.R.B...
http://www.arb.ca.gov/homepage.htm
_________________________________________________________________________
...The 91-94 Explorers/Rangers have what is called a Thermostatic Air Cleaner, Intake Air System and is an important part of your Emissions system...If you do not have this in proper working order, you will fail both the Visual, and your Emissions Test....
Thermostatic Air Cleaner
The below info can be found here and is used just to describe the following...
http://www.wivip.com/index.html?te_idletest.html
The Thermostatic Air Cleaner System is an early emissions control device that was designed to deliver temperature-regulated air to the intake manifold such as warm air for cold engine conditions and cool air for engines at normal operating condition. Thermostatic Air Cleaner systems usually consist of an enclosed air filter housing, with an air intake snorkel containing a thermostatic control valve. This thermostatic control valve controls whether cool air or warmed air enters the intake manifold through a vacuum signal. Later models have used electrically activated thermostatic control valves. After the engine has reached normal operating temperature, the thermostatic air control valve returns to a position to allow cool air to enter the intake manifold for normal engine operation.
Thermostatic Air Cleaner items checked:
1. Exhaust shroud is missing or not secured properly.
2. Heat riser tube, cold air duct, air cleaner cover, plugs, flexible material between air cleaner and vacuum motor, is missing, broken, plugged, taped or disconnected.
3. Vacuum lines or hoses are missing, broken, plugged, taped or disconnected.
4. Air cleaner is missing or "unsealed" for a Pulse Air type system. Wing nut(s) missing.
5. Vacuum motor port is not properly sealed (if dual snorkel).
These pictures show how your vacuum lines properly hook up and also the locations of it's parts...
...This is where your 2 vacuum lines connect at the top, rear of your Stock air box lid..(The bottom half of your airbox is mounted on top of the right front fender) This lid fits on top of that piece...
...This is a pic of the underside of your stock air box lid...Note the vacuum port on this side...Nothing connects to this...(But on the top side of this port is where the vacuum hose for the thermostatic control valve connects)
...This picture shows the proper placement of your vacuum hoses...
...And last but not least, this is your Thermostatic Control Valve located in your Cold Air Intake duct...It is located behind the passenger headlight and most people can only see the vacuum hose heading down to it...Be sure this hose is connected...
_____________________________________________________________________
Stock Air Filter Options
...In this picture the top filter is an STP filter which comes designed with a ridge that keeps all the individual pleats from closing together...The bottom filter is a Fram air filter...I have found that these tend to close up and clog when they are in a real dirty/dusty environment...This shows the bottom, pleat side of the filter...
...This is the top side of your air filter...The fresh air is drawn in from the bottom of the filter, througt this top side of the filter, to your MAF, on through the duct, and to your throttle body...(Again, notice the pleat separation from the STP air filter)
_______________________________________________________________________
Optional Cold Air Intake (CAI) Upgrade
...There are several models to choose from...K&N and KKM, are 2 of the most common to be found on Explorers...I have the KKM that was designed for our motors...Here is a link to their site... http://www.kustomz.com/054094.html
They have installation info so, here is a pic of my setup...The KKM filter pretty much sits just above the bottom half of the stock airbox and attaches to the existing tube...It takes a whole 10 minutes for the swap to stock for the smog test..:biggthump (Note the capped off vacuum line from the motor, the one with the bolt in it)
Note:...If you live in California, these will not pass Smog
Is the True-Rev Induction kit emissions legal in my area?
The True-Rev Induction Kit is designed for competition use and though it does not eliminate any required emissions devices, it does not carry any emissions exemption certificates. The bottom line is check with your state testing stations for guidelines on engine modifications. Our Kits are not C.A.R.B. certified.
...And here is a link for C.A.R.B...
http://www.arb.ca.gov/homepage.htm