Truck stumbles when accelerating

For the last week or so i've been having a on and off problem of the truck stumbling when accelerating. No check engine light or codes are being thrown, i've replaced the fuel filter and that still does not seem to solve the problem. Right now i'm just at a loss as to what it could be.Truck is a 1999 and has 3.4 l V6 with about 170,000 on it now.

 

Need some more info. When's the last time it was tuned up? Millions of threads on here about dirty Throttle body, plugs, etc. MAF sensor. I've found it helpful to do this; Once I find a problem I go to google search. "99 Tacoma stumbles on acceleration, Tacomaworld" The keyword is TAcomaworld. Has helped me through almost 100% of all the issues I have.

 

timing belt