Chugging when accelerating

I have tried everything to fix my 88 runner and just can't figure it out. I have had 2 diffrent mechanics look at and while they fix something and charge me for it nothing has worked. I have cleaned the MAF meter, changed my fuel filter, cleaned my fuel injectors, changed my distributer cap, fixed my muffler, and nothing!! Any ideas? Please HELP!! Before I give up.

88 SR5 V6 automatic trans