so heres what up, a friend of mine drives a 76 280z that was running fine for a while but now runs like crap, and it only runs on 5, so there is no action in #6, he has good spark, fuel to and through the injector but nothing happens, this problem goes away and then comes back... the injectors are getting power... for a while I was thinking fuel pressure but why would that only affect #6, also, he has a new fuel filter... any tips on where to look are greatly appriciated