I just installed a rebuilt 4.0 inline 6 in my 2000 jeep cherokee. And it wont start at all. It makes loud pops and sometimes there is a small amount of flames that comes out by the engine. What did I do to cause this?

 

Sound like a timing problem

 

When you installed timing chain with marks pointing towards each other was dist installed with rotor pointing to number 1 on cap?

 

Its distributorless. But piston 1 was at top dead center and I lined up the ring thing on the camshaft position sensor.

 

i can double check it but im pretty sure the camshaft position sensor is in right

 

Flames out of throttle body? I would check timing again. I rebuilt my engine year ago and I used the 183k mile harmonic balancer that didn't give the correct timing...

 

Was a pita to figure that it was wrong

 

Top dead center compression stroke correct ?

 

How do I figure out if its correct?

 

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.

 

Bingo ....