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Blown CPS???

thebyus

NAXJA Forum User
Location
Albuquerque, NM
Lookin' for a little help -

2001 XJ with stock inline 6 with about 200K miles.

I pulled my front axle to swap in a HP 30. Since I had the axle off, figured I would replace the leaking Oil Pan gasket. Ended up taking off the exhaust and downpipe to get the pan off. Since I had the pan off, I replaced rear main seal and the oil pump.

I packed the oil pump with vaseline before installing and reinstalling the pan. By the time I got everything torqued correctly, temps had dropped to about 35F. Disconnected what I thought was the CPS (turned out to be the other end of an O2 sensor), and cranked it to try and build oil pressure.

Didn't build pressure but did start! Shut it off off immediately as soon as it had started. Tried two more times, same result. So I left it for the night. Well, the night turned into a couple weeks, with below freezing temps.

Finally, got around to putting a lamp under the pan to heat up the oil/vaseline, reinstalled the downpipe, pulled the coil pack to make sure it wouldn't start, and cranked it over to build pressure. Got pressure on the oil gauge, so reinstalled the coil pack, recharged the battery and cranked it.

Now the engine turns over but won't start.

I tried jumping it, to make sure it wasn't a battery issue. Swapped around the relays to make sure it wasn't the ASD relay, and checked the ASD fuse, too. Removed and reinstalled the coil pack to eliminate that. Everything is acting EXACTLY the same - and NO codes!

At this point I am thinking it is the CPS, but since the CPS is a complete PITA to reach on an '01 (the tail connects on TOP of the transmission NOT onto the back of the engine) figured I would see if anyone else had any ideas.

One additional piece of info - I figured since it had sat on jackstands for a couple weeks, perhaps there was no fuel in the system, so I pumped the gas pedal before starting, and then again when I was cranking it (I know, I know) BUT when I added gas it ALMOST started, but not quite.

Still trying to figure out if a CPS can just go bad when the damn thing wasn't even being driven (it started up fine just before I put it up on jackstands)

Any insight would be most appreciated!
 
"
taking off the exhaust and downpipe to get the pan off"
I Never had to do that to get an oil pan off.

Check all the wiring harness connection, you could have disturbed something when doing the work.
I would swap batteries, drop some gas line antifreeze in the tank (you said weeks below freezing there) spray some starting fluid into the TB & see if she starts, if no I'd change the CPS.
 
Yeah, that's where I'm at right now, double checking all the harnesses and connections while I wait for new oem CPS to show up.

The exhaust is an oversized system, with CA emissions, so it has the double cats built into the downpipe - no way to even get to all the bolts and studs on the pan without dropping it.
 
Still trying to figure out if a CPS can just go bad when the damn thing wasn't even being driven (it started up fine just before I put it up on jackstands)

Test the CPS.

Was the battery disconnected for an extended period of time ?
 
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