william mirra

i'm usually pretty good at fixing my jeeps (both 1999 sport cherokees) the red one, after a new fuel pump only starts when air temp is over 85 degrees and sitting in the sun. i put in a manifold air temp sensor, no change. it runs so good when it starts. seems like a lean fuel problem when it won't start, also have put in crank sensor just for fun. Is there an ambient temp sensor? and if so where is it located? Any other ideas would be considered. When it broke it was warming up in the driveway n started running really rough and one of the manifold vacuum lines came off or maybe was blown off by a backfire thru the manifold
the next weekend checked fuel pressure and replaced fuel pump.