tdc on a 88 cherokee 4.0
do we set tdc at 0 on the timing cover or do we use the peep hole on the cover. i set the dizzy up by using 0 and the jeep started and idled but it would pop when you opened the throttle . had to move the rotor 1 tooth cw to get it to run right ?
CF Veteran
Joined: Mar 2010
Posts: 47,923
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From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
You set up tdc on compression stroke cylinder no 1 . dont look at timing mark untill after thats been done then you set mark on balancer to "0" on cover .It should be pretty close all ready.
CF Veteran
Joined: Mar 2010
Posts: 47,923
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From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
::CF Moderator::
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Setting Your 4.0 at #1 TDC
With #1 spark plug removed, turn the engine over clockwise using the 3/4" front crankshaft bolt. You will see the degree marks on your front cover. You will see the timing mark on the balancer. Mark them with chalk or white-out. While turning the engine over, put your finger/thumb over #1 spark plug hole. As the mark on the balancer approaches the marks on the front cover, if you are coming up on #1 TDC, pressure in the cylinder will push on your finger. If there's no pressure, you're at #6 TDC and need to crank the engine over until you see the marks coming together and you get pressure. Set the mark on the balancer to the 0 mark on the front cover.
With #1 spark plug removed, turn the engine over clockwise using the 3/4" front crankshaft bolt. You will see the degree marks on your front cover. You will see the timing mark on the balancer. Mark them with chalk or white-out. While turning the engine over, put your finger/thumb over #1 spark plug hole. As the mark on the balancer approaches the marks on the front cover, if you are coming up on #1 TDC, pressure in the cylinder will push on your finger. If there's no pressure, you're at #6 TDC and need to crank the engine over until you see the marks coming together and you get pressure. Set the mark on the balancer to the 0 mark on the front cover.
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
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the rotor is not lining up like you have in your dizzy setup with the crank set at 0 it is in the middle of 1 and 5 post on the dizzy. seems to be 1 tooth off. thats why i was asking if it lined up in the middle of the peep hole below the 0 mark on the timing chain cover.
::CF Moderator::
Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
the rotor is not lining up like you have in your dizzy setup with the crank set at 0 it is in the middle of 1 and 5 post on the dizzy. seems to be 1 tooth off. thats why i was asking if it lined up in the middle of the peep hole below the 0 mark on the timing chain cover.
CF Veteran
Joined: Aug 2011
Posts: 10,489
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From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
CK..just in case it helps, keep in mind the books and diagrams are all wrong. #1 is at 5:00 as viewed from the side.
Hey! You did save my photo VVV
Hey! You did save my photo VVV
Last edited by DFlintstone; Feb 16, 2013 at 09:05 PM.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0


