So I've posted a couple other times recently for almost the same issue, I've gone through posts and chased my *** severely, I just rebuilt the engine in my 2000 xj, it's the 4.0 had the aw4 auto behind it.
Right after build upstrean o2 sensor stuck in high range threw my fuel maps for a loop, i replaced that all was ok for a day driving it home from work that day i started losing power and fuel mileage went to ****. It died when i got off at my exit and it will not start unless im In the throttle, it wasn't throwing any codes so I had nothing to go off of, I checked spark, we are good there checked fuel pressure and it was low and draining down after a few seconds, I put a fuel pump in it last night as well as a new battery (was 7 years old just time) went to start it this morning am still having the same issues, but luckily we have codes now, I'm getting p0700, p1698, p1687. First thing since the engine was just out and I painted the engine I went through cleaned all my grounds and double checked them, they are all good, I also saw that bad o2 sensors can crash the pcm, so I went through and unplugged one at a time no change, I also saw that a bad crank sensor can crash the pcm, I have not done that yet, I'm not sure if it's worth my time, not sure of the pcm is bad or a sensor or what's going on, any one have any ideas? I'm really at a loss currently, any ideas or help would be greatly appreciated

 

The first thing I would do is pull the battery cables and touch them together and re attach them. These Jeep ECMs are kind of stupid and slow to learn when you do anything new to the system. Resetting them forces them to learn again

 

that's the first thing I did once I cleaned all my grounds and double.checked anything, figured the fuel maps were thrown to **** again the way it was acting and should start fresh, didn't help anything unfortunately, I also cleared the codes with a snap on ethos, they immediately came back

 

My '92 acted the same way once. I forgot to hook up the coolant temp sensor at the t-stat housing. Not sure where it's at on the 2000 but give that a quick check?

 

it's definitely plugged it (very front top of engine) I'll double check the pins and ohm the sensor when I get home though. Anything is worth a shot at this point haha, I did talk to a buddie at jeep, apparently every jeep was wired for a remote start however most didn't come with the components to do so, but when that circuit goes out of has a break it can cause all the cam communication codes and all the issues I'm seeing, I'll update if I find anything there for future reference, but it's getting a new crank sensor tonight another good once over on all my connectors and a good check through the remote start system hopefully I stumble across something

 

What's the fuel pressure in psi?
Are the plugs soaked?

 

it got a new fuel pump last night, sitting at 49 psi I wanna say, haven't pulled plugs I have a new set of champion coppers sitting in the garage waiting for when I'll get home, it's definitely running rich as of now you can smell that, but the pcm and can codes are what are screwing with me currently I'm pretty sure

 

Coolant temperature sensor could be out of whack.
Found this on the web may or may not be legit. You can ballpark it if nothing else, anything way out there the CTS is FUBAR.

 

thank you on that the table should help a ton, I'll definitely be checking out the CTS tonight, at this point it has to be something simple and stupid, the o2 sensors are both new and didn't effect anything unplugging one at a time as I said, ive gone over everything as far as grounds, moisture in connections etc, it's almost worth just replacing the coolant temp sensor while I'm doing the crank sensor too if there's a chance it's throwing the can and pcm off

 

Alright guys I changed out my CTS, I changed my crank position sensor, I replaced my plugs with champion coppers ( old plugs were definitely wet and it had been running rich) checked my 3 main connectors on the pass rear of engine, reset my pcm again, and still have the exact same issue, any one have any ideas? Also does anyone have a few good pictures of the engine grounds and locations just to triple check myself? I'm stumped at this point, almost everything is new don't really even know where to go from here

 

What brand O2 sensors

 

Did the CTS actually test bad?
Did you sweep the TPS for dead spots?

 

not sure off the top of my head id have to go look, they aren't cheapies though I know better than that haha

 

I forgot my meter in my box at work so I couldn't ohm the CTS, I replaced both the CTS and the crank position sensor, reset the pcm and it's the same thing, I'll sweep it in a few minutes here, luckily with the scanner I have here I can watch voltage and percentage on the TPS

 

so monitoring my throttle percentage through my scanner I'm getting weird jacked up readings, goes from 11 percent to 30 to 68 and not showing anything else, obviously we have some dead spots on it, however is it enough to crash the canbus to the point of the pcm not being able to read it? Also I'm attaching a picture of the plugs I pulled out