Engine hesitates and sluggish acceleration

Thanks for your quick reply. I have made a copy of it to give to my mechanic. When the problem is solved I'll let you know. I forgot to mention that it had also backfired and it felt like I had run over something, but hadn't.

Truck started sporadically running bad a couple years ago. I got online to read information on the symptoms, and started with replacing the IAC valve. Didn't help. Replaced the throttle control sensor with no change, replaced a couple other valves that I can't remember the names of, (one on the side of the intake manifold, and the other that sits behind the emissions control sensors at the drivers side rear of the motor, off the fuel rail). I replaced the PCV, the O2 sensor, the fuel pump and filter, the air filter, the spark plugs, wires, cap and rotor, pulled and cleaned the fuel injectors (cleaned the intake plenum while off), replaced the catalytic converter, pulled and cleaned very well, the EGR valve. Ran sea foam through the fuel system a few times, with using the sea foam spray through the intake as well. Checked all my fuses (just the blade style) but I don't have a computer to check for codes. My check engine light will come on while it's running bad for a bit then it goes off, but the truck is still running terrible after the light goes off. The engine loses power after driving it for about a quarter mile, but it will start and idle all day with no symptoms. It passed the emissions test, but runs really bad. After it starts running bad, if I mash down on the throttle pedal all the way, it will keep moving forward, but it performs like it's pulling 20 tons behind it, and will only reach a top speed of around 35 miles an hour. If I let off the throttle pedal to any lesser degree it lurches, and if I let off the throttle pedal all the way, it will idle, but slow to a stop on the side of the road, with the clutch disengaged, motor still running.

Thank you! I appreciate your help with this! I took my truck to a Ford dealership here in town, and they couldn't guarantee me that if I paid them to diagnose it, that they could give me a definite answer. Being strapped for cash as I am at present, I am obliged to do the repair myself. Your site will be a huge assistance in this lengthy saga!

My truck has a problem That I cant figure out. The Truck runs good most of the time but when I stop at a red light/stop sign it will not accelerate it spits sputters for approximately 2 min. Then it will cough and take off normally and run smooth. So far we have replaced the: tps, fuel pump, fuel filter, fuel pressure regulator. And have cleaned the throttle body and air plenum. The cat has been removed. Fuel pressure is steady at 38 psi. Vacuum is steady at 14 hg.

The truck was sitting out in the cold for about two weeks. We saw a leak in the heater hose which leaked into the throttle position sensor. We replaced the sensor and replaced the hoses. When we went to use the truck 10-30 minutes into running it at highway speeds we encountered power loss. It did not stall or quit running but it would go down in power to 20 MPH. Tried the overdrive switch and switching tanks with no improvement. We have replaced the computer, dropped the front tank and visually don't see anything but did replace the filer, which was not clogged. We put a new EGR valve and solenoid, distributor pick-up, EGR vacuum control, replaced all vacuum lines (used diagram under hood) also the exhaust manifold. We replaced the MAF but took it off as it even ran worse. We are at our wits end as this truck has never given us a bit of trouble except a pan gasket a couple of years ago. Any help greatly appreciated.

Mileage is about twelve to thirteen mpg highway.
City ten mpg or so. This truck was sitting and neglected as well.

Things I have done:

1) Replaced the belt tension-er.

2) Replaced rear tank pump.

3) Tested fuel pressure was 38psi before rear pump replacement and I am a little spent because did it solo by lifting back of bed enough too access. Boy I am glad that is done, lol.

I do not want too throw parts at this and am trying too fix obvious problems first.

Can you give some insight on things too look for?
Vacuum readings very good for a motor with 200,000 plus miles. It is burning no oil. Thanks, Rick

It hesitates and sputters and bogs down when I take off in first but when it warms up it runs good going from first to second and second to third and so on.

This is a 300 6 cylinder Ford. It starts and runs fine for approximately 10-12 miles then it starts losing power some jerking. You can shut off the truck and restart and it runs fine for awhile then starts again, shut it off and restart it is fine.

When giving vehicle throttle it tries to bog down and makes clunking noise and will barely move with black smoke computer. Not giving out codes as before and have checked all fuses and wiring. Have replaced fuel filter, air filter, distributor caps, new plugs, new wires, O2 sensor. No gas in pressure regulator vacuum line. Pressure doesn't rise when removing vacuum hose from regulator muffler has big hole in it.