I'd like to confirm that the double throttle solenoid and actuator are working properly on my FD, the FSM speaks to a diagnostic to activate the solenoid to check movement of the actuator. But this is using the factory diagnostic tool, which of course I don't have. Anybody happen to know if there is a way to perform this check through the diagnostic connector as is the case with some other checks?

 

you could tee your boost gauge in there, and you'll see it have vacuum until the car hits whatever temp it needs to open (70c? 80c?)

 

Yes that would work, thanks. The FSM also mentions an engine speed <3,000RPM but that condition might be for only the automatic transmission models. I'll try it and see.

 

why troubleshoot this system? its purpose has been fulfilled. in this ownership era, it serves no purpose. we all know better..... or at least we should

 

If he wants to keep it, or has an auto and probably MUST keep it, I understand why he’d like to confirm it’s opening as it should. Otherwise there might be a performance loss. But I agree with cr-Rex that a responsible owner should know to stay out of boost and WOT with a cold engine anyway.
Don’t think there’s much, if any performance gain in removing DT. That said I did remove mine years ago during a rebuild. It was easy to do (properly) at the time with a block off plate etc., since I was removing all emissions anyway. And I was adding WI pre-TB and thought it might help with that too.

 

Yes I know this is a odd question since most have disabled the system by now. The TB in my car actually has the double throttle plates removed however I have the other parts still attached to the TB and vacuum control system present (CA smog check would likely fail a car if they noticed a block off plate, when I bought the car there was a block off plate from a PO so I refitted the system less the plates). Thing is that I have picked up an almost new TB that is unmolested that will be going on the car at some point and I want to keep it that way. Probably the system in my car is functional now, just moving the shaft without any plates attached but I have no way of knowing. So whenever I get around to installing this newish TB I need to be sure that the system is actually functioning i.e., that vacuum is being applied. I'll just hook up a vacuum gage to the supply hose and go for a drive and see. As far as performance change, I also doubt there will be any impact. I'm not after that last 0.1HP gain anyway with this car, it is quick enough for the street and fun to drive in its stock(ish) form from my POV. Thanks for all the good feedback!

 

I see.... that makes sense