1994 Ford Tempo Engine does not crank. After few minutes st

Ok, so your saying that you turn the key to start and the only noise you hear is the humm from pump under rear seat? If this is the case then your relay to starter is not operating. It;s above inner fender under hood drivers side. Either it is not receiving power from ignition switch or the connection/ground on relay is bad or ignition switch is out of alignment or going bad. Next time it happens pull little rubber plug off relay and and put back on. If it feels to loose pinch it lightly with pliers to make it fit tighter. If this no go rig test light to plug and try again to see if it has juice. If good check fender mounting grounding screws on relay by loose/retighten. If no juice at plug then either the ignition switch is going bad or its out of adjustment. It's under steering colunm under dash. It is operated by wire rod from key which is why it's adjustable.