won't start when hot!please help
 

i have a1988 ford f150 4x4 xlt lariat runs fine starts great cold but when it warms up the starter will turn over really slow 2 or 3 times then it starts smoking the ground wire.it almost sounds like when it gets hot there is too much compression to turn it over.i have two f-150's with the same exact problem.can someone please help me?