slow cranking no start, help me!!!!

I have a 96 xj I just put an apn header on. After I reset the computer by touching the battery terminals together the Jeep at first cranked slowly but would fire, the next day I went to start it and it will crank slowly but will not fire. I has a hard time getting the battery cables off and the cables themselves were very stiff. Do you think the cable broke on the inside or is there something else. I can also smell a faint electrical burning smell after cranking.

I just went through this fiasco on my 99 in December. Slow crank, burning smell..
Only two things could be your problem here

1) which I bet is the most likely is your battery cables have poor connections. I believe on the 96 you have 3 positive leads and 3 negative.
- check the leads on the positive side going from the battery to starter, power distribution box
- and for the negative side check the all the leads from the block to battery, battery to fender, and then the fire wall to block

2) bad starter

As for your burning smell im going to bet on a bad connection that is getting red hot from poor contact while cranking on on the leads

The problem I had was my negative to block was no good and the pathetic ground strap from the firewall to the head was taking all the load while cranking and that sucker was getting red hot and smoking from some oil on it. I assumed my starter was fried until I had someone look to see what the heck was smoking while i tried to start the heep.

If its the cables go with 5-90s cables, or buy em all at your local parts store and some marine battery terminals for about 50~ But 5-90's cables are top tier for sure.

Clean your battery terminals with baking soda & water, a tablespoon of BS per cup of water or so, and a wire brush.
Clean the wire terminals the same way.
Wipe off the surface of hte battery for good measure.
Re connect everything and check your battery voltage with a voltmeter. You want to see 12v. before & after cranking, no less than 10.5 during cranking.

I'm betting on a bad battery connection.

ALSO: Double check each and every last connection you touched while pulling your intake out of the way.

It ran when I got it back together, I didn't reset the ecu untill 2 days later. I Al so tried cleaning the terminals first thing and although it helped a little it didn't fix the issue. I think the cables are original due to their condition so I'm gonna go ahead and replace them today.