the problem im having (at the moment) has to do with the 6pi system.
i took of the actuators cleaned them and the move smothly (by hand and blowing into the inlet tube), also the intake cylinders/valves they connect to move easily and smooth.
when i run the car and move the throttle (i'm judjing by sound but it must rev up to at least 5k rpm) there is no pressure coming from the hard lines that activate the actuators.
the 6pi solenoid valve on rats nest test fine acordding to the FSM but the vacumm lines feeding to the solenoid have no vacumm or pressure.

PLEASE HELP
i am a nebie to this but just find it so interesting, i can do alot on a car once i fiqure out how and why it works.but searching and all kinds of manuals didnt help (much). but i would like to fiqure it out withou taking the intake manifolds and such off and just following the line and fiquring out why it has no air passing through, but i might have to do that.

i dont know if anyone on this forum might know somthing i overlooked or a trick or somthing.
PLEASE HELP
1990 GXL w/85xxx miles

 

Is there a reason you don't think they're working? Lack of mid-top end power?

Off the top of my head, I don't think the S5 NA ECU will activate the aux. ports or VDI if there is no load on the engine (ie in neutral). But on both the 6PI and VDI solenoids, one side is connected to an air pump pressure source and the other runs to the actuator(s). I'm assuming the air pump has not been removed from the car, right?

 

no i have removed nothing(as of yet) i would like to keep everything stock untill i fiqure out how and why it all works, then i might remove airpump, rats nest, ect. a couple years down the road.

 

Well the airpump should never be removed on an S5 NA. The 6PI and VDI depend on it, so if you take it out, you'll basically lose about 40hp.

 

well the s4 na uses 5th and 6th ports to... right? so removing the air pump from a s4 na would result in loss of hp to... right?

 

Nope, the air pump can be removed without consequence on an S4 NA. The aux. ports are activated by exhaust pressure through a line off the end of the split air pipe. The downside S4 NAs run into is once the exhaust is upgraded, the pressure in the line can drop below what is necessary to open the ports. Then S5-like methods of activation become needed.

 

The S4 NA uses exhaust backpressure to activate the ports.

Keep in mind you have to keep the air pump if you have cats. And if you don't have cats, you probably don't have enough backpressure for the aux ports and thus should keep the airpump to actuate them. It's a feedback looop.

 

thanx alot guys, my knowledge has been expanded a little.