More starting problems....

Cherokees are nothing new to me....I have also done a search.....but I am in need of some help here.
I am having problems getting my '96 to start. It will crank and crank and only gives slight clues that it wants to start. After some time it sometimes starts.
It has spark..
Has fuel pressure...
When it does start is runs rough....
It does run hot when idleing...
Checking codes it only gives a catalyst problem....
I recently replaces the 02 sensor at the cat.
Also recently replaced all the injector wires..it ran fine just after the replacement of the wires.
A friend suggested replacing a heat sensor at the front of the block, I couldn't make the connection between that sensor and a starting problem.
Whatyathink?
I will be bringing it into a shop tomarrow morning (friday) I'm not a fan of dumping my problems off on the shop, but I am at an impass.
HELP!
Rick

Jump This said:

When it does start is runs rough....
It does run hot when idleing...
Checking codes it only gives a catalyst problem....
I recently replaces the 02 sensor at the cat.

Click to expand...

Sure sounds like the cat is toast. If it is, there's a factor recall for replacement, so take it to the dealer for evaluation before you pay a shop to do the job.

Maybe the notorious crank position sensor (CPS)? I had similar but not as severe problems with my 96. I read up about how crank positions sensors (on the top of the bell housing, picks up off the flywheel) can be bad. I changed the CPS and the O2's and life was good.

As far as I know, it should start fine even with crappy Cat. It starts with a fixed mixture when cold and doesn't rely on the post Cat O2 until after warm up. Look into the CPS. Another classic one was the throttle position sensor, but I don't think that was such a big deal with 96+.

If the CPS was bad, I believe it wouldn't start at all.
The cat is new(ish) and a bad cat wouldn't stop it from starting....
I'm still mulling this one over....
Thanks for the input so far.