'96 F150 power or lack of .....?

[oldblu65]

I recently acquired a 1996 Ford F150 , 4.9 L inline six w/5 speed OD manual transmission . When I bought it , it had a " check engine " light on . That turned out to be an O2 sensor (which I replaced ) . I then replaced the spark plugs , spark plug wires , distributor cap , and rotor . That helped the performance but it still doesn't have a lot of power and seems to stumble or hesitate when you try to accelerate . I think the MAF sensor and / or the throttle body may need cleaning ? Would this be the likely culprits ? I know a six cylinder isn't going to ever overpower this full size truck but it is a 4.9 L ( 300 c.i. ) so it should have more power than it has . I know the stumbling indicates a problem of some sort ? There were no other " check engine " lights on except the original O2 light . IF the solutions I mentioned above don't work , anyone else have any suggestions ? Also , the fuel level gauge and the engine temperature gauge don't work . Could the temp gauge ( or sending unit ) be contributing to the performance problem by feeding the computer incorrect info ? Any ideas on the nonoperative fuel gauge ? I pulled the dash cluster today to see if the two gauges ( they set side by side in the cluster ) might share a common problem but everything " looked " okay ! Of course , I'm a " shadetree mechanic ( at best ) and may not have recognized a problem there if one exists ? All help will be greatly appreciated ! Mr Moderator , I realized after I posted this that it is in the " E series " section instead of the proper " F series " section ! So sorry , feel free to move it to it's proper place ! I would but don't know how ? Again Sorry !

[rhandwor]

I would go to Advanced Auto or Auto Zone and borrow a pressure tester and check the fuel pressure. They have free loaner tools.
http://www.autopart.com/tools/toolsmain/tool/T_3440.htm
Pull the vacuum hose off the pressure regulator if gas is in it replace.
If this has two injectors pinch the return hose by the gas tank if it runs better replace. Check the fuel pressure regulator. I think this truck has two pumps one in the tank and an inline. Pull the inlet to the inline pump have somebody else try to start hold a can under the line gas should flow this pump primes the inline pump.
Use a copper wire and ground the temperature wire note only one wire if the gage pegs replace the sending unit. Otherwise check out the gage and wire to the gage. The fuel level gage is attached to the float for the primer pump in the tank.