I have a 89 jeep cherokee laredo 4.0 and im having problems when startin it up, it cranks and cranks for a pretty long time till it finally starts and also its happened to me twice where I hit a pretty big speed bump and it turns off on me but only when my back tires hit the bump, I changed the fuel pump, fuel filter and fuel pressure regulator bout a year ago but im thinkin it might be a short or a something can anyone please help me cuz its gettin pretty annoying.