Phauss

iTrader: (3)

I have an '86 NA with a RB header and presilencer and a set of Bonez mufflers. After installing the header/presilencer and reattaching the exhaust back pressure pick-up line, I've noticed that my secondaries don't open up. This has been an issue for about a year now. I've been using this car as a daily driver since then (especially since buying an FD) and haven't had much reason to go over 4k RPM's except for the occassional highway entrance. I've had some time to work on the car lately and I'd eventually like to use it for autocrossing. I have replaced the spark plugs, checked the fuel injectors, and replaced the fuel filter all within the last two weeks (with increased overall performance since then) but the actuators still aren't doing their job.

I've done a lot of research into how to fix my back pressure issue and I've settled on using this thread as a guideline, along with many others: https://www.rx7club.com/2nd-generati...itches-907824/

I have some questions about it, though. Where on the VDI does this hook up? Where can I find those solenoids if I wanted to buy them (and do I still need the ones that I'm using right now with this mod?) The wires for the RPM switch that go to the diagnostic plugs: which one goes where? I'm having trouble figuring out where the rest of the wiring harness goes in the second image, but I'll try messaging the OP about that (I'm guessing some of it goes to the VDI solenoid plug.) Where does that plug for the relief valve go?

I'm pretty much asking for different locations under the hood. I've got a pretty good idea of how the whole thing works and I'd feel comfortable doing this myself, but I'm getting lost in a sea of emmissions equipment info, acronyms, and more theoretical 6-port operation threads than I ever asked for. Sorry if some of my questions sound dumb, but any help I can get would be much appreciated.

(I'm stationed in an area where I don't have immediate access to internet, but I'll check back here as often as I can.)

nicdchris

iTrader: (1)

Well, I would first take an air compressor and test the feed line to the actuators. I've seen actuators stick, i've seen the sleeves stick.

Phauss

iTrader: (3)

I tried manually moving the actuator arms and they move (could use some lubrication though.) I haven't thought of hooking up a compressor directly, so I'll give it a shot and report back here with the results.

Phauss

iTrader: (3)

I got some free time this weekend, so I took the car to the base hobby garage and did some work. I got the chance to rig my 12v air compressor to my back pressure pick up tube and after a couple seconds I heard the actuator arms snap down into position with the applied air pressure. I turned off the compressor immediately afterwards because the compressor sounded like it had to work harder once the actuators opened, as if there wasn't a relief valve to bleed excess psi, and I didn't want to damage the diaphrams. At least I know now for sure the actuators operate.

The main thing I was doing at the garage was replacing the fuel filter. When I blew remaining fuel through the exit tube of the filter, it came out orange on the other end. The exhaust note is much cleaner and fuel delivery has improved since replacing it, but the actuators still didn't open up once everything was put together.

I left the air pump on the car when I installed the RB header/presilencer, even though I received the block-off plate for air pump removal. Could that affect actuator operation?


Sorry for the blurry picture. Greasy hands, touch screen camera phone, you get the idea.

The Laser

Aren't S4 6 ports opened by exhaust backpressure, as opposed to the air pump on the S5s? Do the rods themselves move? Mine had small chunks of rubber in the tube and completely seized it. You could also consider this http://www.rotaryresurrection.com/2n...elec6port.html

RotaryRocket88

iTrader: (7)

You don't have VDI. That's for an S5. You have the 6PI system, which has a small tube for the actuators right along side the split air pipe. It connects to it via vacuum hose.

They're just emissions solenoids from the rack. You can buy them on the forum/ebay for $5 or steal one from your EGR system (if you don't have to smog the car).

The wiring is for the RPM switches. If you buy one, it will have directions. All it needs is power, ground and a tach signal. The B/W wire on the diagnostic plug has switched power. A multimeter will tell you that.

S4s do not have any solenoids on the emissions rack that run the aux. ports. That's on S5s, which is what my setup duplicated. For an S4 you just need 1 RPM switch, 1 emissions solenoid and a modified stock air pump/electric air pump. Mount wherever you like, connect the switch to the solenoid, run air to the solenoid from an air pump, and connect the solenoid output to the aux. port actuator hardline.

The relief dump on the ACV has a large silencer tube that runs to a plastic muffler near the washer fluid tank. The plug w/ a hole went in the plastic piece that's ~8-10 in. from the ACV.

RotaryRocket88

iTrader: (7)

Your actuators don't work because the exhaust has too little backpressure. This happens all the time.

This block off plate is likely for the ACV, which was necessary in my setup along with the stock air pump. You either need to put them back on the car, or go with an electric pump. Lumbar support pumps from driver seats have been used.

Phauss

iTrader: (3)

Sorry for the late reply.

Yep! I hooked up the compressor to make sure the rods move, and they do. The many questions I asked in my OP refered to mimicking S5 port actuation by using RPM switches and air from the air pump.

I have heard about an emissions delete mod to clean up the rats nest under the UIM, but I haven't found a clear write up of how to do this on the forums, mostly because that's not what my objective was. If I can get a solenoid out of it to use for this project, would it be safe to assume that Aaron Cake has a how-to on his site?

I found a thread or two on this forum using google that give the schematics for a DIY RPM switch. It would be cheaper and the purpose of each wire is clearly defined in the schematic. The only question I'd have is if any relay would work for it. Here's an image of the schematic from one of the threads:

(Thread:https://www.rx7club.com/2nd-generati...e-pics-745906/)

That simplifies things greatly for me. I had a pretty convoluted picture of the whole setup in my head until reading this.

Thanks again for the help. I have read many of your posts in multiple different threads and have found all of them useful. I'll get started on this the first chance I get (and hopefully get some clearer pictures this time, haha!) I'll post progress as it comes along.