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CF Veteran
Joined: Apr 2011
Posts: 2,857
Likes: 1
From: Raymore, Mo
Year: 1995
Model: Cherokee
Engine: 4.0
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
150 on a high mileage? Did you do it the correct FSM way or the Haynes way?
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.
Ensure the battery is completely charged and the engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system. (Refer to Group 14, Fuel System for the correct procedure)
(5) Disconnect the ignition coil.
(6) Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.
(7) Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders
Cylinder Compression Pressure
Ratio...............................8.8:1
Pressure Range............. 827 to1,034 kPa (120 to 150 psi)
Max. Variation Between Cylinders..... 206 kPa (30 psi)
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.
Ensure the battery is completely charged and the engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system. (Refer to Group 14, Fuel System for the correct procedure)
(5) Disconnect the ignition coil.
(6) Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.
(7) Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders
Cylinder Compression Pressure
Ratio...............................8.8:1
Pressure Range............. 827 to1,034 kPa (120 to 150 psi)
Max. Variation Between Cylinders..... 206 kPa (30 psi)
Senior Member
Joined: Aug 2012
Posts: 792
Likes: 0
Originally Posted by salad
150 on a high mileage? Did you do it the correct FSM way or the Haynes way?
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.
Ensure the battery is completely charged and the engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system. (Refer to Group 14, Fuel System for the correct procedure)
(5) Disconnect the ignition coil.
(6) Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.
(7) Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders
Cylinder Compression Pressure
Ratio...............................8.8:1
Pressure Range............. 827 to1,034 kPa (120 to 150 psi)
Max. Variation Between Cylinders..... 206 kPa (30 psi)
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.
Ensure the battery is completely charged and the engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system. (Refer to Group 14, Fuel System for the correct procedure)
(5) Disconnect the ignition coil.
(6) Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.
(7) Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders
Cylinder Compression Pressure
Ratio...............................8.8:1
Pressure Range............. 827 to1,034 kPa (120 to 150 psi)
Max. Variation Between Cylinders..... 206 kPa (30 psi)
Senior Member
Joined: Jan 2011
Posts: 730
Likes: 2
From: Joliet, Il
Year: 1996
Model: Cherokee
Engine: HO4.0 I6
Still could use some pointers diagnosing my CPS
http://www.jeepforum.com/forum/f11/c...ailing-639123/
I'm going off of the write up in here. When I hook my OHM meter up to the pins indicated Nothing changes. Does this mean I have infinite resistance? I'm new to OHM meters.
http://www.jeepforum.com/forum/f11/c...ailing-639123/
I'm going off of the write up in here. When I hook my OHM meter up to the pins indicated Nothing changes. Does this mean I have infinite resistance? I'm new to OHM meters.
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Still could use some pointers diagnosing my CPS
http://www.jeepforum.com/forum/f11/c...ailing-639123/
I'm going off of the write up in here. When I hook my OHM meter up to the pins indicated Nothing changes. Does this mean I have infinite resistance? I'm new to OHM meters.
http://www.jeepforum.com/forum/f11/c...ailing-639123/
I'm going off of the write up in here. When I hook my OHM meter up to the pins indicated Nothing changes. Does this mean I have infinite resistance? I'm new to OHM meters.
CF Veteran
Joined: Apr 2011
Posts: 2,857
Likes: 1
From: Raymore, Mo
Year: 1995
Model: Cherokee
Engine: 4.0
Seasoned Member
Joined: Oct 2012
Posts: 444
Likes: 0
From: CA
Year: 1990
Model: Cherokee
Engine: 4.0L Inline 6
Member
Joined: Apr 2012
Posts: 181
Likes: 0
From: Phoenix, AZ
Year: 1994
Model: Cherokee
Engine: 4.0HO
Popped in a new MOPAR thermostat (only 3x as much as any aftermarket one, but it has the bleeder and came with a gasket) and no more overheating while trying to fill the damn thing, I haven't even put in all the coolant yet and and it idles at 210 all day. Seems letting my jeep sit for a while somehow mysteriously made some parts fail 0_o. Thermostat is one thing I am not going to cheap out on anymore, the one I had in it was maybe a year old. Now off to discount to get some new 30's and emissions on Moday.
Member
Joined: Apr 2012
Posts: 181
Likes: 0
From: Phoenix, AZ
Year: 1994
Model: Cherokee
Engine: 4.0HO
So i just went bolt up my front clip and support and the holes do not line up with the new radiator. FML. Time to drill I guess.
Edit: Studs aren't even long enough to go through the top support, WTF.
Edit: Studs aren't even long enough to go through the top support, WTF.
Last edited by avision; Feb 9, 2013 at 01:10 PM.
CF Veteran
Joined: May 2011
Posts: 1,458
Likes: 2
From: Glendale,Az
Year: 1990
Model: Cherokee
Engine: 4.0l 6Cyl
Senior Member
Joined: Jan 2011
Posts: 730
Likes: 2
From: Joliet, Il
Year: 1996
Model: Cherokee
Engine: HO4.0 I6
So the CPS I have in shows a 1 when I touch the leads to the pins. Since it is open that means that it is still in good shape correct? Is it possible for the sensor to still be open but to have gone bad?