NEED HELP with my MAZDA

I got a 91 Mazda B2600i 4x4 pickup with the 2.6 motor. It wont hardly run and Ive changed malot of parts. It acts like its running on 3 cyl. and its loading up. wanted to change computer or mass air meter but cant find any.

please help Its snowing…

Try and umplug your MAF. Does it get worse>?

When I unplug it nothing changes…