i have a 2000 cherokee sport that i messed up real bad. i need to know how to find top dead center without having to tear half the engine apart or removing it all together. any ideas or suggestions?

 

Time to embrace google with a warm hug

 

Can't you use the notch on the harmonic balancer along with 0 on the timing tab? This is assuming you are looking for TDC of cylinder #1

 

Top dead center of what?

What did you do that makes you think you messed up your 2000 Cherokee?

 

i am looking to find tdc on the 1st cylinder, without taking the engine out of my jeep. i pulled the camshaft position sensor out without marking the timing. when i replaced the new one, & tried to start it, itd roll over but not fire up. i was told it was off time. now im trying to reset the timing.

 

INSTALLATION—OIL PUMP DRIVE AND SENSOR
(1) Clean oil pump drive mounting hole area of
engine block.
(2) Install new oil pump drive-to-engine block gasket.
(3) Temporarily install a toothpick or similar tool
through access hole at side of oil pump drive housing.
Align toothpick into mating hole on pulse ring (Fig.
30).
(4) Install oil pump drive into engine while aligning
into slot on oil pump. Rotate oil pump drive back
to its original position and install hold-down clamp
and bolt. Finger tighten bolt. Do not do a final tightening
of bolt at this time.
(5) If engine crankshaft or camshaft has been
rotated, such as during engine tear-down, CMP sensor
relationship must be reestablished.
(a) Remove ignition coil rail assembly. Refer to
Ignition Coil Removal/Installation.





(b) Remove cylinder number 1 spark plug.
(c) Hold a finger over the open spark plug hole.
Rotate engine at vibration dampener bolt until
compression (pressure) is felt.
(d) Slowly continue to rotate engine. Do this
until timing index mark on vibration damper pulley
aligns with top dead center (TDC) mark (0
degree) on timing degree scale (Fig. 31). Always
rotate engine in direction of normal rotation. Do
not rotate engine backward to align timing marks.
(e) Install oil pump drive into engine while
aligning into slot on oil pump. If pump drive will
not drop down flush to engine block, the oil pump
slot is not aligned. Remove oil pump drive and
align slot in oil pump to shaft at bottom of drive.
Install into engine. Rotate oil pump drive back to
its original position and install hold-down clamp
and bolt. Finger tighten bolt. Do not do a final
tightening of bolt at this time.
(f) Remove toothpick from housing.
(6) Install sensor to oil pump drive. After installation,
the CMP sensor should face rear of engine 0°.
(7) Install 2 sensor mounting bolts and tighten to
2 N·m (15 in. lbs.) torque.
(8) Connect electrical connector to CMP sensor.
(9) If removed, install spark plug and ignition coil
rail.
To verify correct rotational position of oil pump
drive, the DRB scan tool must be used.

 

Just be gentle when doing this procedure don't force anything, make sure the oil pump drive is lined up. Some dude tried to mash everything together by snapping off the mounting bolt in the block. He ended up destroying both the oil pump and the camshaft, along with the main & rod bearings, yada, yada, yada.

 

Remove the Timing Chain cover and align the marks shown below to set to top dead center. This is also a great time to change the gasket on the Timing chain cover as these tend to fail and leak oil.


Best of Luck.
cpefy3

 

wow...!!!

so you just broke into this thing removing, distributor, oil pump, cam gears etc and never marked nor had it at TDC to begin with??

let this be a lesson to anyone reading that want's to just start fumbling around with their motor..... LOCATE TDC and leave it there, mark and remark if need be anything in question...

measure twice cut once??

good luck

 

Madness!

 

 

 

Madness? Meaning incorrect? I am fairly new to this too.... I guess it was my misunderstanding that when the marks on the Crank Gear and Cam Gear aligned that the engine was at TDC, as shown in this link:

http://www.justanswer.com/jeep/7ldvy...-computer.html

Am I mistaken? I understand that there is probably a lot easier way of finding TDC, as was previously mentioned (aligning the notch on the harmonic balancer to 0 on the Timing Degree Scale), but was just trying to offer another solution.

If i was mistaken

cpefy3@gmail.com

 

Bring timing mark on harmonic balancer around to .0. on timing covers insert sensor as described ,try and start if no start remove sensor rotate motor one revolution reinsert sensor. Start ...Done...

 

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. Mark the 0 with chalk or white-out.You will see the timing mark on the balancer. Mark it 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.