wont start on 1998 Kia Sportage

Ive had my fuel pump changed and head gasket done it still doesnt start

3 answers 1 comment
check the crankshaft and camshaft sensors
what if theres no compression in 3 of the cylinders?
Cam and Crank Sensors will not cause bad compression in 3 cylinders. Do a leak down of the cylinders to see why there is no compression, maybe some valve were damaged or worn out. May the head was cracked. Was it pressure checked by a machine shop and properly re-surfaced?
Have the brake switch checked/replaced. When the brake switch goes bad the car wont start.