PLEASE help before i pull my hair out!!!!!!

I have an 89 bronco 4.9 that ive posted before with the same problem and after throwing severnal new parts at it, it still isnt running right. When it is cold it runs like a champ but as everything under the hood gets hot, it starts to act up. when stopped at a stop sign or light i can hear a winding sound under the hood that is heard better in the cab. as i take off i lose power. and sometimes straightens up while going down the road but sometimes it will put me fashing my hazards. when it does cut off i have to wait for 10 to 15 min. before it will run again. i have replace every thing in the ignition system from (including) the coil to the plugs. along with the fuel pump relay. it has plenty of fuel and when i pull the plugs it apears to be getting good fire. im starting to thing the fuel pressure regulator. but i dont know.
thanks any advice is welcome and yes the distributer is good it isnt rebuilt.  

Change the fuel filter, and if it still does it check the fuel pressure. Could be a fuel pump going bad. It's a simple easy cheap way to start before the expensive ignition parts.  

Does the whining come from the back of the truck? If so its definately the fuel pump. Or a good posibility is an intake gasket...does it lose any coolant, burn oil, or have milky colored coolant? When it warms up the thermostat opens...which could be pushing an insane amount of coolant into the cylinders. but...its kinda far out there. kinda having a problem like this with my moms 98 expedition. but we had it checked out and it is a head gasket...cause pretty much the same problem.

Hope this helps.
josh  
1995 F250 HD 460BB C6 68,000 miles

is there a way to keep a check on the fuel pressure while in the truck (driving) ive never done that before. the fuel filter is also new. on the ignition side of things, when i checked the distributor cap i found a lot of carbon and metal shavings in it and thats before we replaced everything.
thanks for the help  

it seems to be at the front probably close to the fire wall. but i dont really know. it doesnt seem to use any fluids but i also wouldent expect to much of that from a 37k mile truck? i have also been recently told that the idle air control valve could be the problem it is also new but ive been told that when it is unpluged that the engine should cut off and ive also heard the opposite. when i unplug mine i can hear the idle speed drop. i dont know what it is suppose to do though. but thanks for the help and ill check those out.  

It could also be the O2 sensor(s). I have the same type of problem on my car. There is a way to test them I just haven't had the time myself to figure it out. If you test them it saves the expense of buying new. It is the only thing that I can think of seeing how it only happens after the engine has a chance to warm up. What happens with the O2 sensor is the the heat from the exhaust is supposed to warm up the sensor causing it to measure the oxygen content creating voltage that is sent to the computer to regulate the air/gas mixture. If the sensor is not warm enough to create that voltage the computer responds with a neutral voltage of .45 or something of that nature. Having this can cause the poor response and sluggish acceleration.

I doubt that it could be the idle air control valve because you would most likely have the problem from when you first start the engine.  
'91 K1500 (Stock)
LT285/75R16
Play hard! Play soft! As long as you are having fun!

check for a vacuum leak  hoses or intake,start truck then spray carb cleaner around ontake and vacuum hoses,the egr could be bad sticking open ,and temp sender to computer can be telling computer engine is very cold when warm,not temp sender to dash ,good luck