Any way to run a Flat Top manifold on NB2 and pass smog?
 

I've got a Flat Top that I'd like to install soon and have to smog the car this month. After I put in my stock injectors and ECU back in, I decided to see if it's possible to not run VTCS and not get a CEL, before I put the Flat Top on.

Glad I decided to wait on the manifold because pretty much everything I've done hasn't worked and from reading around a little, it doesn't seem like anyone has ever done this. Which amazes me.

You can not just leave the solenoid connected to the loom. It still throws a CEL. This might work for VICS, but not VTCS. Anyone else got any ideas?

Thanks.

why can't you just leave it plugged in but cap it? there's no position sensor on the actuator or flaps, how does the car tell it's not working? by measuring airflow on cold start?

I haven't done that, but always thought it would be possible/easy

I tried leaving the solenoid plugged in to the loom and capped off all the vacuum ports on the manifold and it still sets a CEL I think after 2 consecutive times of seeing whatever it sees. I could try capping off both of the ports on the solenoid, but I'm not sure how that would be any different from them being open on both sides.

And I'm not sure how to knows, I'd assume by measuring air flow at during warm up. I've still got my wide band if you try driving it right away when it's pretty cold like it's been the last few days, it will get some pretty bad lean tip in. IE 16-7:1 afr.

Put a restrictor into the intake path?
Like a piece of cardboard into the airbox so you can take it out in 5 seconds after the car warms up, do that a couple times and should be ready for smog

Replace NB2 ECU with NB1 ECU.

I have one for sale :-)

There is a vacuum switch teed into the vacuum line between the VTCS solenoid and the actuator. The ECU wants to see verification from that switch that vacuum is present / absent depending upon the commanded position of the solenoid.

So you need to leave the solenoid connected to both electricity and vacuum, and also leave the vacuum switch connected to the solenoid.

This is from a 2002 non-MSM manual, but it should be close:


https://www.miataturbo.net/attachmen...ine=1447965760

Wiring and plugs are completely different.

I didn't say it would be easy!

Now I need that neg prop button.

so basically, re-install the vtcs actuator and just have opening/closing nothing

You don't even need the actuator, just connect a vacuum hose directly between the solenoid and the sensor.

Thank you everyone for your help. Here is the actual CEL that is thrown.

So if you want to run a Flat Top and pass CA SMOG with an NB2, you need to keep the solenoid plugged in electrically and with the two vacuum hoses. One to the manifold and the other the the VTCS vacuum switch by the passenger shock tower.

PSA: There's no where to mount the solenoid on the Flat Top so you're gonna have shit hanging around if you don't make something for it.


https://www.miataturbo.net/attachmen...ine=1448138349