This weekend i began my air pump auxilary port activation project for my 1987 N/A base, because i will be installing a straight pipe soon. Our approach was similar to that of this guide: https://www.rx7club.com/2nd-gen-archive-72/how-air-pump-auxilary-port-activation-330310/, but we have come to a problem. After adjusting the dump valve to start activating the port actuator and open the ports at about 3800 rpm, we found that the ports would open for 1-2 seconds and then close again, even when holding the rpms over 4k. This testing was done with the car in neutral, but upon driving the car it still felt like the ports were not opening, or would only open briefly. Has anyone had the same problem or have any suggestions as to what would be causing this?

 

i'm assuming since the actuators and everything else isn't exactly new, you have leakage somewhere. it's kind of hard to fix this without getting new parts. the only thing i could recommend is just closing off the dump valve more until you get them to stay open. downside of this is that your ports will open a little early.

another thing i could recommend, and would actually be a better solution, is to get an RPM switch and an appropriate solenoid. this way you can set the switch to activate the solenoid at 3800 RPM, and have as much air going through the solenoid as you need.
a switch like this should work: http://store.summitracing.com/partde...5&autoview=sku

and as for the solenoid, just a simple solenoid that allows air through when it gets +12V. a lot of the stock solenoids do this.
hope that makes sense. if you have any questions let me know.

 

Ya we considered that a leak might be the problem, so while the engine was off we attatched a pump to the actuator hose and simply pumped up enough pressure to activate the actuator and then it stayed open, without closing. But the solenoid is a definite possibility. Thanks, and let me know if you have any other ideas as to what the problem may be. Also this motor has about 75k miles on it and is very clean.

 

any ideas at all?

 

Do you have good gaskets for your auxilary port actuators? The stock airpump will create enough air if you don't have a hole in the line. The only place it could be leaking is at the actuator themselves. Call up Mazdatrix and tell them you need two auxilary port actuator gaskets. I've bought them myself. They are like $10 shipped, maybe less.

 

well, air pressure is a funny thing in this instance. i am willing to bet that the initial pressure needed to open the actuators is not enough to keep them open. that is why i mentioned you could try closing the dump valve more. the drawback here is that your ports will open a little early. it's either that or try replacing the parts (gaskets, actuators, etc.) or go with another setup.
this is the reason that Mazda went with the electric solenoid setup for the S5, and eventually on the RX8 everything is electric

 

ya ive done the bit with closing the dump valve more, and even using a smaller nipple to receive less air from the air pump so that i could close the dump valve almost all the way. i still end up with the same anomaly.

 

then you must have a leak somewhere. try closing the dump valve completely and see what that does.