fbse7en

The easy way is to warm-up the car, pop the hood & prop it open, grab hold of the throttle-linkage by hand (of course it goes w/o saying that the tranny should be in neutral w/p-brake engaged/locked!!) and rev-it up til u see the actuators move!! EASY.

Or you could have a friend rev-it-up to 4k rpm while U watch for actuators to move.
EASY.

Aaron Cake

iTrader: (1)

No, that won't work. The engine needs to be under load for the actuators to move. If they move via free revving and the car is an S4, then there is a massive exhaust clog. If they move via free revving on an S5, there is something wrong with the pressure sensor.

fbse7en

Hmmm, Well mine move just fine and I check'd as I described. Why would the engine need to be under load when they are exhaust pressure activated on s4's?! Doesn't make any sense. And there is a lot of pressure coming out of tips....

RotaryRocket88

iTrader: (7)

Free-revving the engine produces little in the way of load or exhaust volume. Just because you feel exhaust coming out the pipes doesn't mean there is back pressure within the system. The set points for the S5 ECU are 0 manifold pressure and 3800 RPM. You can just barely reach atmospheric pressure by mashing the throttle in neutral, but it won't happen until about 5000+ RPM. This is something I've datalogged on my turbo car; an NA may take even longer. At some point you should see the actuators move, but it won't really tell you when they're being triggered. As soon as you let off the throttle to try to hold it at a certain RPM, you'll go back into vacuum & the actuators won't be triggered. At best, you'll just get an estimate.

fbse7en

^So try it.

whoknows

Ive been trying to get the little stuff, which combined is alot of stuff working on my s5 that i just got. The actuators where a pain but as i figured out the only real way is to take them off and see if they were at least functioning by hand. At first i just I just hooked up a longer hose to each and blew into them. The rear actuator moved nicely. The from wouldnt move but ever so slightly till i was blue in the face, lol. So i took off the front actuator and found it wasnt the actuator but the valve. So after using some penetrating oil and rotating the valve back and fourth a million times, i got it free'd up but still not perfect. So i thought i could remove the valve. But as usual and not knowing, i got the bolt and screw holding it on off, pulled it out just alittle and had a grooved washer come out that ill be darned, i couldnt get back in, and didnt know where or how. So i left it out. Ran the car then figured out it was the washer that goes in a groove in the backside to hold the valve from moving in or out on the actuator, lol. So the next day i took it back apart, got the washer back in, and then the valve worked perfectly. I guess have that washer removed and giving it a day of driving to rotate alittle free'er, that oil did its job and it works just fine now.

RotaryRocket88

iTrader: (7)

Try what? I just explained to you how the S5 system works.

Typically what happens is deposits build up on the sleeve inside the intake port, and that can cause it to stop moving freely. If you can free it up without taking the LIM off, that's great, but it may still not quite be as smooth as it once was. Just something to consider if you're ever taking things apart in that area.

Aaron Cake

iTrader: (1)

Since exhaust backpressure is proportional to engine load, it stands to reason that backpressure is low when engine load is low (such as free revving).

While you may be able to get the actuators to twitch, or even move a bit by putting the engine under a bit of load by free revving, it is not a proper test like actually driving the engine under load or applying 2PSI of pressure directly to the actuators (FSM test). It's best to smear some grease on the actuator piston, drive the car at wide open throttle from 2000 RPM to about 4500 RPM in 2nd gear, then check to make sure the grease has moved. That's a definitive test.

Riggs

I've had to temporarily run without my split air pipe on my S5 which is otherwise stock. Will this affect the air pump's ability to actuate the 6PI?

cab91089

iTrader: (3)

For a Series 5, no. The 5th and 6th ports are opened by a solenoid via the air pump. Opening of the ports on a Series 5 has nothing to do with backpressure in the exhaust like the Series 4. I also am running without the split air pipe on my Series 5 Convertible and my ports work.

gerald m

Or you could do what I did couple years back and used a vacuum switch and activated a GM lumbar support compressor bought from Princess Auto for around 12.00 (( about the size of a c cell battery )) . the ports opened in 1.5 seconds after activation and worked perfect every time . have since moved on to soon be opening them with turbo manifold pressure , but it worked fine . For those on a budget it's a good mod . if the ecu (( which I know zip about ))sends out a signal all you would need is a relay to the little compressor . Just something to chew on .