Jeep keeps blowing CPS HELP!!

my 95 cherokee keeps blowing CPS sensors. first one happened about 4 months ago. i didnt fix it until about 4 days ago. that one lasted about an hour of driving. second one lasted about 45 miles. it died on my way home and exibited signs of CPS failure. i checked there are no shorts. could the ECU be bad and blowing them? maybe i have the wrong one installed? they were all used off working 4.0L of similar years. what do i do?!?!

thanks
-chris