when trying to accelerate my jeep stumbles it will only drive at 1/4 throttle and sometimes full throttle, 1/2 and 3/4 throttle wont work and engine tries to stall (sometimes does) dont know what is wrong, i do know that its not the TPS or fuel filter just relpaced them.

 

it could b wires, plugs, dis.,coil, or fuel pump mine did this too i replaced everything but the dis. and coil have a new fuel pump on da way. also i noticed mine did this when it was below half tank. newayz check this n let me know

 

Check ur fuel pump but testing the fuel rails pressure! That is a common problem we have.

 

ok so its not my fuel pump cause i can hear it running and the pressure at the fuel rail is good setting at about 31-32 psi

 

ive got a similar issue and im gettin alot of advice that it may be my cat converter ive also heard injectors. but could be your iac too or any of the other stuff listed but im gonna pull my pump and inspect it and replace injectors and cut pipe infront of cat to see if any of that fixes it and if not then im just gonna baby it till i deploy then drop a 350 or 305 in it

 

I would check your catalytic converter first (claygrassmann beat me to it, hehe), if it gets clogged, it creates tons and tons of back pressure, and the motor will hesitate really bad at anything past idle and will eventually just not run at all after it gets warm...