Ford Repair: electricial, vacuum hoses, air control valve

Question
I have a 87 f150 4x4 with a fuel injected 4.9L inline 6 cyl.  When ever I start it up it run's extremly rough.  I have talked to what I would call "parts changers" so far and in the process have changed the O2 sensor and the idle air control valve with no luck.  I learned how to run the self check with the computer and my volt meter.  And it is saying that the BP sensor is out of self test range  the HEGO sensor circuit indicates system lean.  At idle the engine idles up and then almost stops and idles up and continues on and on.  I start removing vacuum hoses from the vacuum tree and the motor will level out and idle at a rough but steady idle.  And it will not rev. up past about 2000 rpm's and if you hold the engine at a high idle for to long the fuel rail and exhaust manifold will turn cherry red.  When I ran the "running self test", the computer took over the engine and it ran great until the test was over then it went back to how it runs normally.  Do you have any suggestions.  I am tired of guessing.  I have been told that the timing should be around 10 degrees but the engine is running like it has a terrible load on it so I dont think a timing light is going to be very helpful right now.  I have checked the spark with the timing light on each spark plug wire and they each have spark and have replaced the plugs also. Thanks for your time.  David

Answer
have a professional test your truck-bp sensor should be map sensor mounted on firewall with one electrical connector and one vacuum hose-check and make sure hose is connected and not broke-if it is ok
quit guessing and throwing parts at it as there are number of things that could be wrong-cherry red exhaust is extremely lean or rich-probably not timing problem and you are right hard to check accurately running like this-you will get hego codes-bp codes and iac codes with it running like this also-iac will not cause red exhaust either-be sure and change oil after you find problem as it could have gas in it. just because you get a code that don't mean that sensor is bad ex. vacuum leak will give hego code-good luck