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Installed new cam and lifters. now jeep will not start

J

juicebox

NAXJA Forum User
Location
north carolina
hey guys i have a 97 jeep cherokee country that had a bad missfire. i found out that my number six cylinder was completely dead. after digging into it i found i had a completely collapsed lifter on the exhaust valve on the 6 cylinder. because of that dead lifter it wore a cam lobe off the cam. so to make a long story short i replaced the cam and all 12 lifters. also replaced the head gasket and most other gaskets as well.

now that its all back together the jeep will crank over great but will not fire. it has fuel and spark but will still not fire. has anybody else ran into this problem before or have any ideas on what i should check.

97 Jeep Cherokee Country
4.0 Engine
Automatic trans.
 
Distributer is installed correctly. what do you mean by degreeing the cam in. when i installed it i lined the two timing marks up on the cam and crank together. however today at work i checked aldata and found that the to gears should be turned. i will tear the front cover off again tomorrw and re align everything and see if that works.

wha exactly do you mean by degreeing the cam though?
 
Degreeing the Cam is a performance thing. It's basically fine tuning the static cam timing based on where you want to see a performance gain. It's generally only a degree or two one way or another as it's done with offset keys.

When the #1 Cylinder is at TDC with both valves closed, the Camshaft gear marks should align. That's about all you really need.

Also remember than once you rotate the engine, those marks will not realign until you go through all 4 cycles of that cylinder.

-Ron
 
juicebox said:
when i installed it i lined the two timing marks up on the cam and crank together. however today at work i checked aldata and found that the to gears should be turned. i will tear the front cover off again tomorrw and re align everything and see if that works.
Click to expand...
You better read that again!

I just reviewed my Haynes manual. It said to install the chain with the marks aligned, then rotate the crank and **** the pins to verify the install.

At this point you could take Digger87xj's advice and look for low compression, or pull the valve cover and watch the valves on the #1 cylinder.
 
WB9YZU said:
Degreeing the Cam is a performance thing..... the Camshaft gear marks should align. That's about all you really need.
Click to expand...
You misunderstand the purpose of degreeing a cam as it is not just "a performance thing." It is to verify that the cam is installed as it should be. Manufacturing tolerances in the cam grind, the blank, and the timing set plus user error can put the cam in either severely retarded or advanced. Which will cause major problems. Just because two marks line up doesn't really mean anything.

The timing set goes dot to dot. Cam gear at the bottom of the gear, crank gear at the top of the gear. The chain counting nonsense only works with the stock chain.
juicebox said:
Distributer is installed correctly.
Click to expand...
You might want to check that again because something isn't right. Make sure you are on the correct TDC. When the camshaft is installed dot-to-dot that isn't the correct TDC to set the distributor in.
 
Last edited:
Re: Re: Installed new cam and lifters. now jeep will not start

WB9YZU said:
When the #1 Cylinder is at TDC with both valves closed, the Camshaft gear marks should align.
Click to expand...
Actually, no.
When the cam and crank dots are aligned dot to dot, the engine is at TDC compression #6. 2 revolutions of the crank will bring it to TDC compression #1. Then, both dots will be at 10 o clock or so.. They can be center line checked with a straight edge..
Now the distributor can be installed.
 
Last edited:
Digger87xj said:
Actually, no.
When the cam and crank dots are aligned dot to dot, the engine is at TDC compression #6. 2 revolutions of the crank will bring it to TDC compression #1. Then, both dots will be at 10 o clock or so.. They can be center line checked with a straight edge..
Now the distributor can be installed.
Click to expand...
Correct.

90% of no starts or poor running after engine work are the fault of the distributor being installed incorrectly.

Also, don't forget to check the obvious. Make sure the crank sensor was plugged back in. Check the ground on the dipstick mount on the back of the head. Make sure the injectors are all plugged in. Make sure the TPS, IAC, and MAP are plugged in. Make sure all the vacuum lines on the manifold are plugged in. Make sure you plugged the CPS back in (if it was disconnected). Make sure the coil is plugged back in. Check the plug wires and firing order. Etc.
 
So if I'm reading this correctly all of you agree that the mess about counting the pins between the timing marks on the chain in nonsense. When I first bout the jeep I put a new timing chain in it but u never turned to motor so I just left everything as it was. But I thought I remembered something about the pin thing that was off.
 
Ok guys so I just pulled the front cover off to check the alignment again. I have it set with both timing marks lined up facing each other. After trying what digger said about turning the motor 2 turns it ends up in the same location. Not with the cam at 10 o'clock. I checked to make shure the motor was at #1 tdc before turning by putting my finger over the #1 spark plug hole to feel for compression at that cylinder. Am I doing something wrong or is everything ok at this point.
 
yeah you're right... 2 turns will bring it back to dot-dot. One turn from there should get you to TDC compression #1
 
juicebox said:
After trying what digger said about turning the motor 2 turns it ends up in the same location.
Click to expand...
That is how it should work. The cam turns at half the crank speed.

When you put your finger over the plug hole and feel compression you are on the compression stroke. Continue to rotate until TDC where the notch on the balance lines up with the 0 mark on the timing cover. This is there you align the distributor.
 
Taylin that is how the motor is timed now. When I would try to start the motor last time it just sounded like starter was turning the motor over. It didn't sound as if it was trying to fire at all. All grounds and connectors were in place and connected as well.
 
are you sure grounds and CPS are installed/plugged??
 
all grounds and cps is connected and installed. i relocated the ground that goes from the fire wall to the back of the head to the rear bolt on the fuel rail. i thought that might be the problem so i disconected it and installed a wire from it to the battery. that still didnt help it any. but other then that all grounds and connectors are plugged in and connected
 
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