my wife just got a truck from her dad, he bought it for her to travel back and forth from georgia to florida in, here is the problem,
1. it was a northern truck has some rust under fram and chasis
2. the gas tank had been patched and has been replaced
3. the transmission lines sprung a leak and replaced
4. after $500 in repairs the truck was running great
BUT THEN
5. after about a half a tank of gas went through, it started to buck/jerk and wanting to stall out, sometimes taking off from a red light it wont even move?
6. going down the interstate if you go to pass a car it falls on its face and starts bucking
7. when this happens as your going down the road if you can,, you put it in neutrual and turn the key off and then restart the engine-put it back in drive its ok again for a while
8. it does not do it on a consistant basis i took it to the shop the checked the gas psi and said it was normal???
im wondering fuel pump, filter, but that would not explain the turn it off then turn it on (temp solution)
9. it has starting getting worse everyday though,
10. I was told that the triton engine at a certain speed it cuts out a number of cylinders for better fuel economy, if this is true can it be a faulty system shutting down the cylinders when i need them to run?
CONFUSED on this ford, im sorry to say i have been a chevy man all my life, but this is a nice truck and we love it, it just has a big bug in it,
PLEASE HELP !! thanks

 

also forgot to mention, no i dont have a check engine light on or anything like that,
sorry i didnt mention it before

 

Change the fuel filter and put some GOOD injector cleaner in the gas (Techron, BG44K, or Gumout with Regane).

False.

 

already added seafoam, which was recommended by the mechanic,,going yo change the filter next.. thanks

 

when were spark plugs and cops changed? sounds like you might have a miss under load.

another thing to look into is throttle body and iac cleaning.

 

The 5.4l Triton has a Safe Shutdown Coolant System. There is a sensor, CHTS, (Cylinder Head Temperature Sensor), on the front of the driver's side head, right under the intake manifold. When it senses that the engine is running too hot, it will alternate between 4 cylinders, using the 4 non-firing cylinders as air pumps to cool the block. If it keeps getting hotter, the engine will then shut itself down.

To my knowledge, it does not shut cylinders down to save fuel. I agree with Chief, I would take a look at the COPs/Plugs as well as your Idle Air Control Valve, Throttle Position Sensor, and Mass Air Flow Sensor.

Also, I would check for vacuum leaks, or potentially a bad ground wire. I have seen, with my own 5.4l, that I forgot to bolt down a ground wire while rebuilding it (got ahead of myself and wanted to see it run) and did not bolt down a ground wire. I believe this caused an issue with either the PCM or GEM module. My own experience, not necessarily the problem here.

-Alex
http://www.youtube.com/achubbard117

 

Sounds like water in the fuel. Run a good gas treatment of your choice at the next fill up and change fuel filter. Might also check condition of coils, wires (if any) and spark plugs, could also be an ignition failure under load.

 

i have been working late all this week, i will work and try to tackle this truck this weekend, i will try all you guys advice, thanks and i also will update, so if it could help someone else also.. thanks guys