Help-won't stay running

Okay, I have an 88 Pathfinder. It's our fun vehicle. Well we were out having fun with it and hit a pretty hard bump. Right after hitting the bump it acted like it wanted to die, then it wouldn't stay running. So we checked everything out turned it back on the the rpms went all the way to six grand. So we shut it off and were just kind of stumped. We have another for parts so we have all the sensors and parts, but just don't have any idea where the problem lays. Now when we started it yesterday it doesn't want to stay running again...almost ready to give up, any suggestions???? Please! :banghead: