I'd suspect the battery or the starter motor.
H

Hi,
    We have several rangers in my family and they all break down. Your oil
cunsumption can be caused by first; bad oil seals on your valves, 2;
worn valve guides, 3; or bad rings. First is to check the valve stem
seals to see if they are bad. With your valve covers removed you can
visably check the seals. Look for cracks and hardness. Most likely they
are bad. You can replace them yourself if you use a small engine valve
spring compressor to remove the clips, spring retainer, and valve
springs. and most importantly you have to pressurize the cylinder with a
compressor so that your valve doesn't fall into the engine. Oh yeah' you
have to remove the valve train. Ford had some problems with the stock
heads on the 2.9 V6. There is a better and improved head available for
these. I have a friend who is a machinest here in San Diego. His name is
Marty and his # is 619-697-4094. He may be able to help you further. He
knows motor weaknesses very well. I've been doing business with him over
20 years. He's an excellent machinest. He can also get the improved
heads. If your engine is running hot be careful not to crack any heads.
You can do a compression test with the throttle plate wide open. Take
out all the spark plugs and have someone crank it over with the gas
pedal down. Write down your readings. Then put a little oil in the
cylinders to check pressure again. If it increases dramatically your
rings are bad. If it doesn't change that much your valves or seals need
work. Oil will seal the pistons, but not a bad valve. If your
compression is good (at least 100psi with no more than a 5% varience
between all the cylinders) you may want to take your heads in for a
valve job. Be very careful and remove your coil wire. With a live coil
you will get shocked, start a fire, or cause your battery to explode.
With all this in mind you will soon get up and running again.
    Your hard starting is caused by a hot engine/starter. When a starter
gets hot the internals expand and you either have to cool it down so
that it restores the starter or give it plenty of amps to move it. This
is a common problem with older Chevys. A cool engine will not overheat
the starter. This should fix your problem. Good luck.
Jessie

Try changing the ignition module on the distributor.  Most common cause of
Ford motors not starting when hot.