I'd be looking at the ignition system. You r problem has the sound of a bad secondary igniton component, Plugs, Wires, Cap, Rotor, Coil.

 

i forgot to mention that it has a new cap, rotor, wires and plugs. the plugs are a nice golden brown when i pulled them. also it runns better when i advance the timing.

 

could also be a fuel delivery problem

Check the fuel pressure and volume. I've been seeing about double the number of fuel pump and injector problems since the fuel has had alcohol added to it.

the air flow meter is cabable of causing this type of problem, but usually they cause a problem at part throttle and work well at full thottle, but if the door is hanging up it could act that way

 

well i just got the truck recently and the guy i bought it from said he changed the tank and pump in it. but i will check it. also the door on the mass air flow sensor on the air box does open and close like it should. i can shine a flashlight up in the lid and watch it open and close when you get on the gas and what not.

 

the fuel delvery can be reduced if there is a power supply issue to the fuel pump

check the pressure and delivery, if it's OK thenn move on.

also you say the ignition parts are new, what brand are they?

 

they are the carquest brand. same plugs as toyota uses from factory. it ran fine when new parts were put on. it sat for a couple months and it now runs like this.

 

check the fuel delivery and look for signs of contamination

 

if you floor the gas it slowly climbs to the rev limiter. but if you only go about half throttle it will imediatly climb in rpm's with no hesitation




Could be a dead spot or more in the throttle position sensor! If the PVC valve was even stuck closed, I dont C how it would limit it like u got. I cant imagine the Blow By building enough pressure up to slow the engine down, maybe blow some gaskets, but thats it.?