Engine swap running rough

I just completed an engine swap in my 2001 Cherokee Sport with a reman 4.0. When I turned the key, the engine strained to start, but it started. However it ran very rough, responded to giving it gas but then quit. I did that several times before turning everything off and calling it a day. I'm getting oil pressure. I did the CPS alignment procedure as outlined in the FSM. Along with the new long block, I replaced the entire cooling system, new plugs, new oil pump, but did not replace the injectors...the gasket kit that came with the new engine had o-rings for the injectors, and I put those in. There is a pretty heavy gas smell while the engine runs, before it gives up. Any thoughts?

It may just be trying to relearn the tune and curves it needs to idle. My jeeps generally run like crap and won't idle for a bit if I take the battery out for a while or have to jump them. Since you have oil pressure and it smells like it's running rich, as long as you keep an eye on the temp it really can't damage the motor unless it was put together wrong. I'd grab a fire extinguisher and take it on a short run around the block a few times to see if it smooths out - keep an eye on your temps and keep your foot in it a little if it won't idle without stumbling. It will probably smooth out shortly.

edit: check to make sure you're not leaking fuel anywhere, too.

TPS? :dunno:

When I put a new head on my HO 4.0, it would die sometimes at idle. I guessed it was from the new valve springs being stiff. After a week or so of daily driving, it ran like a charm

"...engine strained to start, but it started..."

1. FULLY CHARGE the battery.

2. LOAD TEST the battery.

3. CHECK THE MAIN CABLES for clean connections and tightness.

4. Try starting it again.

ON LATE MODEL VEHICLES WITH COMPUTERS low voltage will cause erratic running conditions.