I could really use some help.
I have a newly rebuild 2000 cherokee in my drive that I've been trying to get started. I have a thread running on that.
This morning I swapped camshaft position sensors with another 2000 (I have 3 - 2 runners and a third project xj) just to see if the project xj Cam Pos Sensor was bad. I swapped the entire distrib shaft between the two. I started the runner with the non runner's cps and CEL started flashing. It ran but ran rough. I felt I had found a problem.
I trier to start the non runner with what i thought was the good cps. It would sputter and hiss like it wanted to start. Prior I got nothing out of it. so I thought I had found the problem. I swapped them back and the running xj would now not start.
I went to auto parts store and bought a replacement cam pos sensor and installed it in the runner. runner will still not start.
Also noted that yesterday I had all kinds of fuel at the fuel rail when I pressed the test port valve. Now I get a little dribble (just like the non runner).
Any Help will be greatly appreciated.
Thanks

 

OK so as they sit right now... they are both back to their original configurations from when you first started troubleshooting correct??

With the non runner trying to start and sort of sputtering... it almost sounds like what mine did when the Crank position sensor went out on me... but with having next to no fuel @ the rail... I would think a fuel issue.... unless the crank position sensor is messed up and is sending a signal that is not telling the ECM to send fuel to the rail...

 

The runner has a new Cam pos sensor it and the non runner has the old cam pos sens from the runner. Also the non runner has a new Crank Pos Sensor (installed yesterday).

I was just turning over the "runner" and it fired and wanted to run a few times. But the starter motor was getting hot and batteries are nearly dead so I gave it a break.

Since the Cam pos sensor controls fuel injection timing i think the computer has to some how learn the cam position relative to the crank position. there is no ignition timing adjustment. you can loosen and spin the dizzy shaft and the computer is suppose to adjust. But how can it do this with out the engine running. The dealer must plug it in and load some defaults?

thoughts?

 

Also, I put a fuel gauge on the test port. It reads around 45 psi.

I dont understand how swapping cps (dizzy shaft and all) and then swaping back could cause a no start condition on a running xj.

I installed a new cam pos sensor... and still no start. I pulled the dizzy out and rotated the small end (oil pump end) 180 deg and still no start.

Even tried disconnecting the pos battery terminal and grounding it out...

It fires and wants to run but wont.
Now I have 2 non running xj's.
I think I'll town this one to the shop tonight and be at their mercy...

 

ok.... I found the problem.
Ignition timing is not adjustable BUT the dizzy / cam pos sens location must be set.
I found the procedure. It requires the use of a scan tool. I should not have removed the whole shaft. The procedure shows how to get it close but it has to be checked with a DRP scan tool???? what ever that is. I hope I can get it close and then drive it in to have it checked.

I miss the days of the good old distributor.

 

I got mine back from the shop two weeks ago and it ran fine. When I got hope I noticed that my negative battery cable was turn the wrong way putting stress on the cable so I loosened the nut on the battery terminal of the wire, removed the wire and repositioned it and tightened it back down. After do that my engine would crank but not fire.... I started messing with everything and I mean everything, but all it would do it crank and nothing else, no spark no fuel not nothing. So I figured it ran before I messed with the negative battery cable so I took it off and moved it back into the position the shop guys put it in and boom it fired right over. So now being totally confused I put the cable back to where it was when it would fire and then it worked... now I am super confused(long story but there is a point to this)

So after getting it started I started messing around with the cable and nothing. Took the cable back off the battery and turned it so it was pulling on the cable again and low and behold it would not start... WTF is all I could think... Now no matter what direction I turned it the engine would crank but not fire. So I ripped my starter relay apart so I could crank the engine under the hood and messed with the negative cable. She simply would not go, so I did a reset of the pewter by this method,

remove positive cable and short to engine, AC compressor will do fine for no less then one minute.
put cable back on.
turn the key to run but do not start the engine!!
now turn on the headlights and then turn them off
then turn the key off

After doing just that she fired up and ran rough for a few second and has run fine ever since.

Something in the cherokee computer gets out of wack and "rebooting" it seems to help.

Try this and see what happens, because you are swapping out known good parts and it is not working so that leave the computer, and like I said mine would not fire up from just moving the negative battery cable. Hope this helps.

 

Running!!!

step one: # 1 piston at top dead center of compression stroke. Remove first spark plug and turn over engine by hand. with finger over hole feel for pressure and look for mark on harmonic balancer to line up with 0 deg TDC mark on timing indicator.

Step two: install dizzy shaft with notch for connector pointed rear ward (CPS removed) AND a tooth pick or small drill bit installed through housing alignment hole into hole in cam pos sensor actuator plate.

step three: tighten shaft retainer clamp bolt, remove tooth pick and install cps to top of shaft.

Step four: Check with DRB scan tool to insure that fuel injector timing is within range.

Thanks for the replies.... I really thought it was a matter of the computer just having to learn the new position of the camshaft sensor. You would think this would be the case since it knows the pos of the crank and therefore the cam. Not sure why there is a cam sensor anyway. computer should be able to fire the injectors off the crank position????.... but its running. now its off to get the rebuilt one running. It is exactly the same situation.