hey, anyone noe why my rpm keep droppin from ~1090 and it drop to ~500 for a minute then come bak to normal around 1090....

 

Not in my prelude. But in my old Grand AM - the voltage of the battery also drops at the same time, so, i'm guessing it has something to do with the charging system. Maybe a faulty voltage regulator in the alternator........

 

I bet it's the IAC valve

 

iac valve? shoot i dun think my tb has that thing, i think my mechanic bypass that, not very sure, but dun the iac valve, it make the rpm rev up and down constantly if it somethin wrong wit it???