First of all I would like to apologize for asking this question but it is to help out a co-worker. He is driving a nissan 240 (hence the apology) whenever he approaches 70mph his car hesistates (almost like a small "hiccup,"). What would be the cause of this? I am certainly not familiar with fuel injection. Additionally it occurs in idle at times ( a small "blip,"). Sorry to even ask this question but any help is appreciated.