My '91 cherokee runs fine during the winter, but when it warms up outside my temperature gauge almost reaches the red even after only driving about 20 to 30 miles. It has never over heated but as gotten close. I have done a coolant flush and gotten a cold air intake, but it still gets really hot. I was wondering what I can do/add to cool down faster

 

Replace the thermostat, and check to see if any of the radiator hoses are leaking. Also it could be the water pump. The cold air intake wouldn't bring overall engine temps down.

 

Check the radiator, water pump, fan clutch (most overlooked piece of the cooling system) and thermostat. Replace as necessary. Also replace hoses if they are old and brittle. Cooling systems in the xj are mediocre at best so everything needs to be in tip top condition

 

X100 on this statement......... To service the entire cooling system costs about $250 +/-, money well spent with summer just around the corner. With what you describing, fan clutch is a very likely suspect, with engine cold(and off), spin the the mechanical fan with your hand, run engine to operating temp, shut down, let it sit for 5mins, then try to spin the fan again if properly working it should be tight, not loose as before. If you dont know how old the water pump is replace it, new not reman., new thermostat (dealer or at least Stant Superstat), this would be a good time to eliminate the heater control valve as well, and while everything is apart, flush each part of the coolinf system separately(Block, Radiator, Heater Core). Good Luck