bjw6259

89 NA, previous owner did an emissions delete/rats nest removal. Dealing with 15 mpg during my commute, and wanting to regain my low-end torque, I've decided to try and replace the air pump, aux ports and VDI. Had to buy new sleeves, actuators, and solenoids, and I finally think I have all the parts necessary to get this done.

One thing I keep noticing while searching around is people keep mentioning the use of RPM switches to get the aux ports open at 3800 and the VDI at 5200 rpm. I think the wires for the actuators on my car are all still there (looks like there's a bunch of colorful, unconnected connectors), so I assume those can be used to actuate the solenoids as they used to. Do people usually set about ripping those wires out during an emissions delete and that's why everyone is so hot and heavy for these RPM switches, or does an emissions removal somehow stop those connectors from putting out voltage at the right time?

I've just been poking around for a long time, and can't seem to figure out why you wouldn't just leave and use the original wires controlled by the ECU. It sounds like the main goal is usually to replace the air pump with some sort of electric pump to reduce engine drag, which can just as easily be done using those connectors and a relay. Or if the reason is to tidy up, sticking in 2 RPM switches and wiring everything up hardly seems any cleaner than using the old system...

Dak

I don't think having the aux ports and VDI not functioning would be the cause for that gas mileage. At least not if they are set to their high rpm setting. I regularly get around 20mpg and I've had my aux ports and VDI wired open for years. Pretty much since I put my header on in '99. I did not however mess with the rat's nest except for replacing all the stock vacuum lines with silicone. I did remove the air pump and air control valve but left the soleniods in place. Maybe there is something not quiet right with the rat's nest removal.

Dak

I think you need the rat's nest back in place for everything to function properly. The actuators don't have wires going to them only small hoses. They open from air pressure from the air pump on '89-'92 cars. The wires go to the solenoids which in turn control the air flow to the actuators based on whether the signal they are receiving has them open or closed. The air control valve(ACV) is integrated in this as well.The original rats nest's metal lines had two seperate systems. One was the vacuum lines for the engine. the other was the lines connecting the ACV, the solenoids and and the actuators for the aux ports and VDI with the ACV getting it's air pressure from the air pump. I would think that yes those connectors would be used to activate the solenoids as they used to once everything is connected as it used to be. Either by the stock rat's nest back in place or hoses of your own. I don't know if people usually set about ripping those wires out during an emissions delete or not but since the air pump and ACV is usually removed there is no longer any air pressure to open the actuators. That's why people use the rpm switches. To control whatever setup they are using to open the ports/VDI. I never thought about it before but seems to make sense to use those connectors and relays to control your system.
I would imagine a person could use just portion of the stock system that routes the air to the aux ports and VDI and seal off any lines that would have went to emissions stuff and use an electric pump for your air source.
Oh well, good luck. To be honest I've never missed them. I had a functioning system at first when I first put my header/presilencer on. I could tell a slight difference when I first removed them( below 3500rpm) but once I ditched the stock mufflers I got the bottom end I lost back. I've thought about making mine functional again but they've become stuck open and won't move any more.

bjw6259

Seems like my brakes might be dragging a bit (noticed it while replacing wheels today), so the ports might not be responsible. I've heard mixed opinions on whether aux ports and VDI affect gas mileage, guess it depends on the rest of your setup.

Surprising how many writeups there are on using RPM switches and electric air pumps. Seems like if you're gonna do an emissions delete, why not just have the ECU connector actuate a relay connected to a solenoid or linear actuator? Maybe that'll be my next move once I get them working the way they were originally intended.

hashman626

could you please tell me where you bought your sleeves and actuators?!