My 1988 Mitsubishi mighy max is acting its missing. Hesitates bad. And the radio flickers on and off.

Did you change the spark plugs? How about the distributor cap and rotor?

It also drains the battery to nothing.

Yes all that has been changed.

Any suggestions...

Do you have a carburetor or fuel injection? Either way I would use a good fuel system cleaner like Sea Foam. The radio issue is probably a bad connection in the power supply. Did you clean the battery terminals and cable ends?

How many miles on the engine and have you checked the compression?

Ya all that stuff checks out there is 210000 milles on the truck.and I cleaned all the connections.

Y do u think drains the battery tho.

If you have a carburetor the hesitation could be from a bad accelerator pump. I would try a fuel system cleaner for a few tanks and check the timing. The fuel system cleaner won't fix a bad accelerator pump but it can unplug fuel injectors and carburetor passages.

The battery drain is a different and unrelated issue. Either you have something that is left on draining the battery, a weak battery or possibly a short somewhere.