So I'm replacing complete interior of a 98 cherokee. Had the battery disconnected for a few days and when I reconnected it it now has a hard start issue. It has to be cranked over way longer than before. It will also idle rough sometimes. When it's idling rough it wants to stall out if I turn on defroster and electric fan kicks on. It ran perfect before I disconnected the battery. Always started with just a slight crank and ran nice and smooth. Any idea what screwed up having the battery unhooked?

 

Just went through the "rough idle" thing in my 90 4.0 Double check you didn't knock a ground,or even a vacuum .
What year is it? Make and model?

 

I'll definitely do that. Only other thing i did under the hood was check fuses.

 

So I cleaned battery terminals really well. They were very corroded for some reason. Also noticed the wrench I used to loosen the terminals the other day was covered in corrosion. Anyway it seems to be starting easier but stil has a random skip. At one point it started to die and when I gave it a little gas it was very hesitant and popped a little and didn't want to rev. Only did that a couple times. Then I let it idle for a while and it was fine but like once every minute it would skip

 

Started it yesterday. Started quickly but skipped badly. Started a few more times and it stopped skipping. Tried again this morning and it cranked very long before it started but didn't skip once it was running. Not sure what's up. CEL on sometimes so I'll have to try to borrow a scanner and pull codes.

 

May have unlearned the IAC and going the process of a relearn. If that's the case then you could probably help it by cleaning the throttle body and the IAC both.

 

Right. Was thinking something like that but anytime I ever had battery problems in an xj the iac always made it idle really high and it cleared up pretty quick.

 

So this morning I started it and it skipped. Shut it off and started it 4 times. 4th time it ran fine. Will pull codes today and post back

 

Too busy to do much with this thing this weekend. Skipping bad all the time now. Reminds me of the way they run with heat soak. Kinda weird for these symptoms to appear only after having battery unhooked. Just fired up my 99 wich sat for the last 5 months with a dead battery and it runs excellent

 

Update. Got a scan tool but haven't used it on this xj. Been working on another for now. Recently though I have gone to start it and when I turn the key it clicks then power is gone. Have to fiddle with the ground cable for the battery to get it to start. So it's obviously a ground problem causing all of this

 

Ground problem is likely. The other issue may be that the computer lost all the stored info in it. Keep driving it and it should come out of the funk it's in. It needs to "re-learn" idle speeds, etc. Should be good after 50 or so key cycles.

 

ao it's been about a year since my first post on this. Have t messed with this thing in a while. Yesterday I pulled the coil off and cleaned up the grounds where it mounts. Did this because about a month ago I moved the wires around that plug into the coil and it idled perfectly for about ten minutes then the skipping returned. I replaced battery terminals and cleaned up the ground to fender and connection to pdc. All of this and it's stil skipping. No cel anymore.

So far I pulled the plugs and cleaned and regapped them. One plug was a little nasty looking so I pulled the inn for plug from that cylinder and it ran worse. Also threw two codes. One for evap leak and forget what other one was. Cleared codes with scanner and none came back. Disconnected upstream O2 and it didn't change how it runs at all but did throw a code obviously. Plugged it back in and erased code. Still no cel for skip. Did notice a little arcing around plug wires one time. Also noticed this yesterday.

 

It's cracked around to both sides. Probably all the way through

 

If this is the cause not sure why it would start skipping after having the battery disconnected.

 

Not sure where to go next. Haven't finished this thing for this reason. Can't afford to throw parts at it so I'm going to do whatever free and cheap things I can first. Not sure where to go from here though. It's skipping bad and not setting off cel. While idling it will start to idle lower and the iac will begin to let a bunch of air in and it stumbles so bad it almost stalls. Used to stop sputtering if I held the rpms a little high but now it skips all the time. Seems it's running rich but can't smell has in exhaust. The cat gets the sulfur smell once it's hot. That's all I got for now.