Lifted98XJ

Hey guys, looking for advice on why my xj won't start. It cranks and cranks but won't fire up! I just recently replaced my heater core and got it all put back together and now she won't start. I've read forums sayin the CPS was a common problem and all the symptoms I've read about it are goin on with my xj. But I replaced it and still nothing. Fuel gauge reads empty. Amp gauge bottoms out and says check gauges and one time it said "no bus" on the odometer. I checked the ASD fuse just in case and nothing. Any help would be appreciated!

belvedere

Are you missing fuel, spark, or both?

CCKen

Did it start and run okay prior to changing the heater core? You may want to verify that all the wiring connectors under the dash are secure, especially the large gray connector (C201).

Mcameron

i hate to be "that guy"......but is there gas in it?

first things i would check would be to make sure the fuel rail is getting gas and check the fuel rail pressure.

then i would check to make sure your plugs are sparking.

that should help narrow down the likely culprit

Lifted98XJ

Yeah it ran fine before the heater core change. My fuel gauge doesn't even move when I turn Over the ignition. I'm gonna run a double take over all my connectors and make sure but I didn't think I missed anything. I was however in the engine bay whilst trying to get the last nut off the hvac box down below the manifold. She has a half a tank. Heard that the big white connector next to the big gray one under the steering column may not be all the way connected either. Just not sure why it would show all the signs of a failed CPS and still not working after a new one unless I bought a faulty one.

Mcameron

did you buy an OEM CPS?...ive heard some of the after market sensors can be hit or miss....

Lifted98XJ

Yeah I've read that too but figured I'd try my luck and ran to AutoZone to try and get this thing back on the road ASAP.

ozzy1234

If it ran prior to theheater core then I'm sure it's something as simple as an electrical issue. Also is it on jacks in the front or rear?? Because I had a fuel issue last week because I have mine on jackstands in the rear due to that I need a rear end but I would start it every so often and I ran the gas out so I put in 4 gallons and still wouldn't start. So after checking the fire I just let it down and level and it fired right up. I'm not sure how the pump angles in the tank but it was probably a rogue air pocket or trash. But now that I have fuel in it I jacked it back up and it runs fine now. But in your case it sounds like a bad ignition connection somewhere. This is my first jeep so I'm learning as I go. Good luck

Lifted98XJ

Yeah I'm going to tear back into her and recheck all my connections/grounds tonight when I get off. My second xj but never messed with my first one really so this is all kinda new to me as well! My dang blower is stuck on defrost now too so that'll give me another reason to tear her back apart! Lol.

Lifted98XJ

Ok. So checked all my grounds/connections and still nothing. My fuel gauge moved a few times and then bottomed back out. Just changed the cps and I'm out of ideas. Fuel pump isn't even kickin on at all. Checked all fuses and everything.

sycoglitch

What connection and grounds did you check. And is this on your 98?? You didn't say. Chances are you knocked something lose. Not sure why it would be the cps if it worked fi e before. Did you put back the old cps and check all connections in your dash board

sycoglitch

Aftermarket CPS crap out all the time even out the box. Secondly, have you also tested your battery to make sure you didn't run it just below the needed point to start the jeep. I still say check all connections back but at the same time clean battery terminals and try a quick jump start to rule out the dome lights draining a possiblly weak battery

Lifted98XJ

Yeah I've jumped it a few times with around 15-16 volts and nothin. Double checked all the connections under the dash an battery. It's on my 98.

Lifted98XJ

I have a feeling it may be a ground, if not a faulty cps. My fuel pump isn't kickin on and my fuel gauge is bottomed out. Tried to jump the pump and it won't kick on

Lifted98XJ

UPDATE:

Finally got her going this afternoon. Turns out the alarm someone had installed must have triggered it to thinking it was being stolen or somethin when I pulled the dash out and everything for the heater core. It shut down my fuel pump so I couldn't start it. Ran a quick hot wire from pump to relay and she starts every time! Will dig more into the security system later on to check out the reason.