I have a 1999 F150 4.9L 5spd which hesitates and almost dies when I depress the accelerator sharply in neutral or with the clutch disengaged. It is like there is no accelerator pump and there probably isn't because it is fuel injected.

I am getting plenty of fuel from the fuel pump.

It acts like it is just cold when I try to actually accelerate the truck on the road. It gets better when it is warm but not much better.

Any ideas?

 

When was the last time the plugs/wires/cap/rotor and filters were changed? What is the fuel pressure?

Have you checked for codes? Many times there can be a problem with having a Check Engine Light on. Warm up the engine then do this: Ford Fuel Injection » How To Run a Self-Test or purchase one of these: Equus 3145

How long has this issue been occurring? Was there any service performed beforehand?