I have a 90 NA. Are the 6 ports supposed to open when you rev the engine while the car isn't driving? I've watched them open when I put direct current to the solenoid but not otherwise when I rev the engine.

 

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and no, only when the car is under load

 

my 91 na has almost no power whatsoever between 0-10mph. Once I get above 10-15mph then the car wants to run. Not sure what the problem is, but could the 6port system cause that? The car idles strong, and will rev fine in neutral, but under the intial load of getting the car moving it pretty much sucks.

 

IMO you need a tune up. Check your timing. Get your Injectors cleaned. Check your AFM sensor (air fuel meter) TPS (throttle position sensor) plugs, wires, and yes your 6 ports. unplug the solenoid (the brown one) and while the car is running connect it to the battery and give the motor a little gas. You should see the 6 port actuators working if there is no mechanical problems or vacume leaks. Do the same with your VDI. However neither the 6 ports or VDI are activated under 4500 or so RPM so they shouldn't be responsible for the stalling problem your having.