I was reading the thread below by STiVI in regards to his misfiring EA82. Can't think of anything to help him, but my Hitachi carbed EA81 just started misfiring and running like crap the other day. I initially thought it was ignition problems so I tried swapping coils, distributors, etc. from my other parts cars. To make a long story short, I couldn't really tell if I was making much of a difference or not. Things may or may not have changed, but it still ran like crap no matter what I tried.

 

Well, I was reading the response in the other thread from Skip, and he is asking about hearing a popping sound from the intake. I am DEFINITELY hearing a distinct but intermittant popping sound from within the carb.

 

What exactly does that indicate?

A big vacuum leak of some sort - unless the popping is comming from the ASV valves - which is (at least somewhat) normal - try plugging the BIG metal tube holes you see in the bottom of the air cleaner box - if it goes away it is the ASV system, if not, big vacuum leak ....

 

or you have an exhaust leak.

Thanks for the quick help. I'll give it a try after lunch today.