Ok so my 86 Toyota pickup idles just fine and runs fine at full throttle, but when im trying to maintain speed 15 mph to 65 it doesn't matter the speed its all about the throttle amount and the miss/buck seems to occur around 25% and only there, I've put a new full pump, a used maf sensor, used solenoid resistor, used computer, new tps, plugs, wires, cap, air filter, fuel filter and I still can figure it out any ideas??????????

 

How is the wiring around the igniter?
How is the wiring around the intake manifold?
How is the wiring to the O2 sensor?

 

The wiring around the igniter and intake look good, I actually just ran a new ground for my injectors, so I've been all in that and it looks fine. The o2 sensor actually isn't hooked up at all (wire was layed across exhaust pipe by previous owner) , but it never has been, and its only started to act up recently, I've owned the truck for over a year

 

New update, did a couple tests on the tps and it tested out good, but it still misses, checked timing again all is good there drained and rinsed out gas tank put new premium in nothing seemed to change it at all it just always runs rich and sputters at about 25% throttle, any ideas please I have seat he'd and can't seem to track down the problem!!!!!

 

I would suggest while truck is idling, try giving a slight tug on each fuel injector connection. The white connectors with the wire clips can look like they are making a good connection and actually not be on completely. Possible when the rpms up that maybe the wind is loosening the connectors?? It has happened to me and it acts like a cylinder is misfiring.

 

Have you figured out the problem yet??? I have the same thing happening but at like 3/4 throttle...I have to like feather the gas pedal because if I get to that point it kinda chokes and loses power but if I go full throttle its fine.....