I was given a 98 f150 (it says spi 4.2 l on the top of the engine? ) and about 2 years ago I had the clutch fully replaced. But its acting up again and now whenever I push down theres no rsistance. In addition, I have issues just switching gears and it idles high causing me to stall out alot.

Any suggestions?

 

The first thing I would do is check the fluid level in the clutch master cylinder. Be aware there is probably a deep rubber cup under the cap that must be removed to check or add brake fluid to the clutch master cylinder.