i've got a '93 2wd 5 speed F150 with the 4.9l. it's always had a slightly rough idle and it has been getting progressivly worse. also i've noticed that when you touch the gas pedal, the engine stutters and the rpm's drop a lot for just a split second, then it rev's up fine, like there's a delay in fuel delivery or something. so far iv'e replaced:

fuel filter
plugs,wires,cap,rotor
ignition module
Throttle position sensor
MAP sensor
several bottles of Amsoil injector cleaner
air filter

also sometimes in the mornigs it will die when i go to back up. as soon as you let the clutch out enough to start moving it will start to die, so i push the cluthc back in but it still runs lie it's under too much load and after a few seconds it will die.

the MAP made a slight difference, as did the wires plugs and rotor but it's still doin the same thing.

any help would be greatly appreciated
thanx

 

Other things to look at are the IAC, EGR, and PCV systems, and for vacuum leaks. Any CEL? Any codes?

 

iac tests good EGR is disabled, (runs the same even if i reconnect it) pcv valve is new. CEL only comes on because of the EGR.

 

btw is there an idle relearn procedure or something for the TPS?

 

also, i noticed that when the TPS is dissconected, the engines idles a little high, but runs perfectly without a miss.

 

anyone?