4.0L hesitates until full throttle? 6 months.. still no solution
 

I have a 93 ranger with the 4.0 v6. The truck starts fine, idles ok.. sometimes the idle jumps but just a little. When I start in 1st gear the truck runs great, as soon as i shift into 2nd gear i have a loss of power. The truck hesitates until almost full throttle and then it jumps and comes alive! Its got great power once I get past the sticky spot.
The truck throws a check engine light every once in a while but i cant relate it to anything. Plus, every time I take it to oreily to get the code checked, it wont read a code and just says that its unable to retrieve any information.

I have replaced all of these in the past couple of months:
Fuel Filter on side rail under drivers side
Mass air flow sensor
Spark Plugs and Wires
Throttle Position Sensor TPS
Ignition Coil (or coil pack i'm not sure of the correct name)
Air Filter
And i have ran lots of sea foam through the truck hoping it was a clogged injector.

Does anyone have a clue? My next step was going to be O2 sensors

Thanks
Blake

hey there. im having the exact same problem with my 96. i have also changed everything you have posted except for the o2 sensor. i have had 2 different scanners on my truck, the obd2 reader came up nothing, but the guy i bought the truck from had another scanner which threw out an emissions code. wasnt really a code it just showed the colour yellow which meant emissions.. i am at a loss as well with this... its gonna be about another month before i can get to o2 sensor but please keep in touch and let me know if this fixes your problem, cause im all out of ideas lol.. cheers

Just trying to help!
 

This sounds like it could be a loose or broken wire. Maybe even a ground issue.

perhaps a little more info would help... on wires or ground... there really only one ground on the engine and thats the ground strap from firewall to the block.. thanks