I have a 94 v6, but i only get about 18 mpg. I changed the spark plugs, wires, and all three coil packs. What else should i do?

Ok so I have found out is not the coil packs, plugs, or wires. My car gets up to 55 then it starts to shake and does not accelerate anymore until i give it more than half throttle. Only does this in over drive. Would a bad fuel injector, tires needing rotated or reweighted, or a bad connector cause this? If something else please let me know.

Ok so I have found out is not the coil packs, plugs, or wires. My car gets up to 55 then it starts to shake and does not accelerate anymore until i give it more than half throttle. Only does this in over drive. Would a bad fuel injector, tires needing rotated or reweighted, or a bad connector cause this? If something else please let me know.

sounds like the tranny..

crossed coli pack??tps bad??

I know its not the transmission as i have taken it to a transmission shop. The coil packs are put on right and we made sure of that. How hard is it to change the TPS?

I know its not the transmission as i have taken it to a transmission shop. I am not car smart so i don't know what a tps is. The coil packs are put on right and we made sure of that.

TPS = Throttle positioning sensor

Ok so I have found out is not the coil packs, plugs, or wires. My car gets up to 55 then it starts to shake and does not accelerate anymore until i give it more than half throttle. Only does this in over drive. Would a bad fuel injector, tires needing rotated or reweighted, or a bad connector cause this? If something else please let me know.

For a test at 55mph steady state cruise in OD..lightly apply the brake pedal to disengage the lock up feature in the converter.If the shake goes away,have a chat with your tranny guy once more.

could be a plugged catalytic converter or a stuck injector as well.