ChrisS Posted December 1, 2023 Report Share Posted December 1, 2023 Hi, 1) Does the MX5 NB2 VVT map given in the sample startup pcl file match the original OEM configuration? 2) Would you expect I'd have to add a fair bit of gain to get the car to have the target match the actual? I had to add about 20 to the base proportional before it came close to matching. Also I tried changing the oil o rings and it improved it but only slightly no real change to the gain needed. 3) I have found the VVT "actual" hunts the "target" by 5% or more oscillating very fast say a couple or more times a second, is this to be expected? Is there a filter or something that I should change from the default pcl file? Regards Chris Quote Link to comment Share on other sites More sharing options...
Vaughan Posted December 1, 2023 Report Share Posted December 1, 2023 There is a known issue with the nb2 plugin where it needs a diode added, get in touch with tech support please Quote Link to comment Share on other sites More sharing options...
Ken Hill Posted December 15, 2023 Report Share Posted December 15, 2023 I read this post last Sunday and sent an e-mail to Link Tech support and have heard nothing back. The VVT position trace in my log files has oscillations as seen below. Is this an issue? I can't imagine the cam actually moves this quickly. If it is an issue, does the addition of a diode fix this issue? Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 15, 2023 Report Share Posted December 15, 2023 Yes, this will be the lack of recirculation diode on the output causing this, the solenoid with be rapidly snapping fully open/fully closed similar to an injector, rather than floating about some middle position proportional to current like it is meant to. This was a design oversight that was somehow missed. Quote Link to comment Share on other sites More sharing options...
Ken Hill Posted December 15, 2023 Report Share Posted December 15, 2023 How do I fix it? Quote Link to comment Share on other sites More sharing options...
dx4picco Posted December 15, 2023 Report Share Posted December 15, 2023 On 12/1/2023 at 7:02 PM, Vaughan said: get in touch with tech support please Quote Link to comment Share on other sites More sharing options...
Ken Hill Posted December 15, 2023 Report Share Posted December 15, 2023 I contacted Tech Support with no reply is 5 business days. I just reached out to them again. Quote Link to comment Share on other sites More sharing options...
koracing Posted December 15, 2023 Report Share Posted December 15, 2023 If you're not getting a reply on the email - try using the live chat on linkecu.com and get the email address of whoever is chatting with you to send the request to so it can be forwarded to the correct person. Any chance the necessary information could be provided here for a field fix in the case someone doesn't want to can't send in their ecu? Is this an issue for VVT on all similar solenoids across the G4x lineup or just plug-ins? Is a recirculation diode the same as a flyback diode? Perhaps like a 1N4007? Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 16, 2023 Report Share Posted December 16, 2023 14 hours ago, koracing said: Any chance the necessary information could be provided here for a field fix in the case someone doesn't want to can't send in their ecu? Is this an issue for VVT on all similar solenoids across the G4x lineup or just plug-ins? It is specific to some NB2 plug-ins only, all stock was recalled for updating when the problem was discovered so there arent many out in the field. 14 hours ago, koracing said: Is a recirculation diode the same as a flyback diode? Perhaps like a 1N4007? Yes, in this case the VVT is high side driven, so effectively a diode in parallel to the solenoid. Something like a 1N5404 would do it. Quote Link to comment Share on other sites More sharing options...
Ken Hill Posted December 20, 2023 Report Share Posted December 20, 2023 I got ahold of Simon via Chat on the Link website tonight. Simon told me this issue requires a board-level repair, not fixable in the field. My ECU is on its way back to Link. Quote Link to comment Share on other sites More sharing options...
castillaricardo Posted December 21, 2023 Report Share Posted December 21, 2023 @Adamw If I understand correctly, then a diode is not necessary when swapping an NB2 motor into an NB1 car running the NB1 plugin ECU? I was planning to use Aux 4 (previously the VICS solenoid) for the VVT output. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted December 21, 2023 Report Share Posted December 21, 2023 2 hours ago, castillaricardo said: @Adamw If I understand correctly, then a diode is not necessary when swapping an NB2 motor into an NB1 car running the NB1 plugin ECU? I was planning to use Aux 4 (previously the VICS solenoid) for the VVT output. correct, diode is only needed because high side is being switched instead of low side and this was only being done so that the pnp could also support the mazda speed turbo NB2 model. Regular low side switching has no issues. castillaricardo 1 Quote Link to comment Share on other sites More sharing options...
Ken Hill Posted February 16 Report Share Posted February 16 Update on this topic. My ECU returned on January 21. Not a bad turnaround time considering Christmas and New Years during this time period. I have not installed it yet because we are having a cold and snowy winter here in the mid-atlantic region of the US. I'll post a log of the VVT position when we thaw out and I drive my Miata again. Quote Link to comment Share on other sites More sharing options...
Ken Hill Posted March 30 Report Share Posted March 30 Got the MX5 out last weekend. Addition of the diode solved this issue. koracing, castillaricardo and Vaughan 3 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.