mx5_rydog

Hello all, this is my first post on this forum so excuse me if this is not the correct category for this. I have a '97 miata with a franken motor bp, 99 block and crank, 05 vvt head, and forged rods and pistons on e85, gtx3071r turbo and diy manifold and exhaust, and it is running on a speeduino ecu. My only problem I haven't been able to solve is with the vvt control. I have been running it with the vvt solenoid not plugged in and the car runs great besides not having vvt functionality. I have been searching the forums about the pid settings and it seems that no matter what I do in the settings the best I can get the vvt is inconsistent functionality with around 20 degree fluctuations in vvt angle and at worst it goes from 0 degrees to max advance and keeps going back and forth or does nothing at all. I am not sure if this is a problem with the solenoid/vvt system (I got the head with unconfirmed functionality for cheap) or if it could possibly be a settings issue. I have also read on some threads about a diode being needed when adding vvt to a chassis that didn't come with it although I am not sure how that would need to be wired in or if that is even a thing that is needed. Appreciate any help. (on a side note, I am currently out of town however, when I am back I can include my tune file/screenshots of my vvt settings and take some data logs to better illustrate my problem)

Physician

are you running nb2 cranck and cam sensor? or the stock na8 cam sensor?
you need the nb2 cam sensor.

mx5_rydog

yes, I’m running nb2 cam and crank sensor, I recently found that my keyway was messed up so my crank sensor was off by a few degrees as a consequence. Ill try out the vvt again within the next few days now that’s it’s fixed.