I have a 1990. Ok guys so before I was having an intermittent idle and idle dip. Replaced TB, ISCV, AFM, and all associated gaskets. Cured the intermittent idle. The iscv gasket was ripped in a couple places and as hard as a rock. Reinstalled everything and no intermittent idle. Now I just have an idle dip issue (which was present before from time to time) when warmed up and driving when I release the clutch pedal and go from a gear to neutral it drops way down to around 400, then slowly comes back up ... sometimes I even have to blip the throttle to get the idle back to 850. The ECU idle is set and is the same as the cars idle. So I rather not increase ECU idle to compensate ... I rather find out whats going on. 65,000 miles .... Am I looking at bad 02 sensor? Coolant temp sensor? Fuel injectors? Fuel pressure regulator?
Anything else I forgot to mention? Thanks so much
( and I have read every post on this issue on miata.net, club roadster, etc etc .... unfortunately just a lot of pissing in the wind and when people solve their issue they never really explain what solved it. And the thread ends ... Thanks for any input, guidance, help.