Help Locating speed sensor

Hi everyone, I’m having an intermittent starting problem with my Jeep Liberty. Some mornings it starts normally, but other times it cranks for several seconds before finally starting. Once the engine… 

Se le mete el agua y sospecho que es por la rejilla del aire acondicionado

Cambios bruscos problemas en baja temblores y problemas en la goma trasera se frena sola cuando va en marcha

Changed ignition coil and spark plug with number 2 ignition coil and plug and still have number 6 misfire cleaned injecter checked wires and found no problems with any of them.