VDI Solenoid?
Since I don't remember off the top of my head which solenoid does what, if that is the one for the VDI valve, the consequence of not having it working is that you will lose power above 5500 rpm (or whatever rpm it is) when the valve is supposed to open. If you wire the VDI valve open as a temporary solution so you have full top end power, then you'll have less power below 5500 rpm which is where you drive most of the time.
Should be easy to find one really really cheap. I actually just went and looked through my stuff, I unfortunately threw mine away a while back. They all go bye bye if you eliminate your emissions / rat nest.
Since I'm about to do just that, I've been wondering what the consequences are. Now that I've realized that the VDI runs off the air pump (I think), removing those solenoids and the air pump means no VDI. Do people with the S5 who've removed the emissions/airpump just live without the VDI?
My logic is that when you remove the rats nest and air pump in the name of a cleaner looking and more simplistic engine bay, you are also removing a big part of your usable powerband just so you can get those traits. I will never again remove all of that stuff from the engine. I've been there and it looks nice and is easy to clean but your powerband will suffer noticably from not having everything working properly. The reality is that doing all of that isn't going to make you faster. The opposite is actually true.
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6PI is the brown solenoid. It's on the vac diagram on page F1-7. There are also only 2 kinds of emissions solenoids. You can substitute some of the other ones for your broken 6PI solenoid, so your aux. ports will work until you get a replacement. If you look at the bank of solenoids, you'll see 6PI, VDI (white) & relief (blue) all have the filter facing the driver's side of the bay. These 3 (along with S4 EGR solenoids (yellow)) can be interchanged.
this is interesting I think. I pulled out my solenoid cluster last night, from my S5 NA and started wiping the grime off them to compare to the FSM, Instead of the plastic being color coded, all of my solenoids are black and each one has a little round colored sticker on top. Cheap! I was able to see three of the five part numbers and they are all the same and I'm guessing that the other two are as well. You can almost certainly interchange these things.
Building off what RotaryRocket88 was saying, the VDI solenoid (as well as 6PI, Relief, and s4 EGR) all work like this:
For VDI and 6PI, when the solenoid is de-energized any pressure in the actuator will be vented to atmosphere through the filter. When the solenoid is energized (normally by the factory computer but you could use an rpm switch if needed) pressurized air from the airpump will flow through the solenoid and to the respective actuator.
For relief and EGR it works the same way except it supplies manifold vacuum. When manifold vacuum is supplied to the relief valve on the ACV the secondary air vents back out to the air cleaner rather than flowing to the cat or exhaust ports. When manifold vacuum is supplied to the EGR valve a small amount of exhaust recirculates back into the intake manifold.
Interestingly enough, most aftermarket 3 port boost control solenoids (Greddy Profec S for example) work the same basic way. The boost controllers cycle the 3 port solenoid on and off to rapidly pressurize and then vent air to a wastegate.
For VDI and 6PI, when the solenoid is de-energized any pressure in the actuator will be vented to atmosphere through the filter. When the solenoid is energized (normally by the factory computer but you could use an rpm switch if needed) pressurized air from the airpump will flow through the solenoid and to the respective actuator.
For relief and EGR it works the same way except it supplies manifold vacuum. When manifold vacuum is supplied to the relief valve on the ACV the secondary air vents back out to the air cleaner rather than flowing to the cat or exhaust ports. When manifold vacuum is supplied to the EGR valve a small amount of exhaust recirculates back into the intake manifold.
Interestingly enough, most aftermarket 3 port boost control solenoids (Greddy Profec S for example) work the same basic way. The boost controllers cycle the 3 port solenoid on and off to rapidly pressurize and then vent air to a wastegate.
Building off what RotaryRocket88 was saying, the VDI solenoid (as well as 6PI, Relief, and s4 EGR) all work like this:
For VDI and 6PI, when the solenoid is de-energized any pressure in the actuator will be vented to atmosphere through the filter. When the solenoid is energized (normally by the factory computer but you could use an rpm switch if needed) pressurized air from the airpump will flow through the solenoid and to the respective actuator.
For relief and EGR it works the same way except it supplies manifold vacuum. When manifold vacuum is supplied to the relief valve on the ACV the secondary air vents back out to the air cleaner rather than flowing to the cat or exhaust ports. When manifold vacuum is supplied to the EGR valve a small amount of exhaust recirculates back into the intake manifold.
Interestingly enough, most aftermarket 3 port boost control solenoids (Greddy Profec S for example) work the same basic way. The boost controllers cycle the 3 port solenoid on and off to rapidly pressurize and then vent air to a wastegate.
For VDI and 6PI, when the solenoid is de-energized any pressure in the actuator will be vented to atmosphere through the filter. When the solenoid is energized (normally by the factory computer but you could use an rpm switch if needed) pressurized air from the airpump will flow through the solenoid and to the respective actuator.
For relief and EGR it works the same way except it supplies manifold vacuum. When manifold vacuum is supplied to the relief valve on the ACV the secondary air vents back out to the air cleaner rather than flowing to the cat or exhaust ports. When manifold vacuum is supplied to the EGR valve a small amount of exhaust recirculates back into the intake manifold.
Interestingly enough, most aftermarket 3 port boost control solenoids (Greddy Profec S for example) work the same basic way. The boost controllers cycle the 3 port solenoid on and off to rapidly pressurize and then vent air to a wastegate.
they really held nothing back for these cars.
i love it.
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alexdimen
3rd Generation Specific (1993-2002)
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Oct 23, 2015 01:50 PM
