okay, I was failing emissions with horrible HC and CO readings, in both idle, and cruise, i found a connection problem with the the sensor on the passenger strut tower as well as replacing the cat. This allowed the car to pass fine at cruise, but fail exactly the same on idle, except for lowering the CO readings to half of what it had been before, 8.1 now 4.0. The CO still needs to come down alot and the HC's are reading 960, down from 961 on before putting new cat on and fixing sensor.
I am supposing this is just a sensor problem ?? I have replaced the Throttle sensor with one off a car that had recently passed emissions fine, and had the same results. also I replaced that electrical piece underneat the stock air box, also replaced the air flow sensor.
all of these replacements were taken off a car that had passed emissions.

Okay, other symptoms, I have bad gas mileage, Strictly freeway, EZ driving, i got 16.6, in town i avg 12-13. My idle isnt great, it wavers around, then holds after about 20 seconds (only wavers 100rpms tho). Also when i give it some gas in neutral and then let go, the rpms go up , come down a bit, holds for a sec, then drops again, then holds, then comes back to idle.
Any Ideas?

 

Forgot to add, i have EGR blocked off, and its a 86 NA rx7.

 

your gas mileage is fine. Rotaries are thirsty engines

 

i heard that if you pour some alcohol into your tank just before you test it helps you pass emmisions since it burns really clean. I don't remember what kind but it is worth a shot.

 

First of all, do a full tuneup. Change plugs, wires, filters, oil, etc.

Now, adjust the TPS (search for info). Check for vacuum leaks. Test the ACV valve and check the temp sensor on the water pump housing. The Haynes manual has all these procedures on it.

As a last resort, adjust the idle air mixture screw on the shock tower (passenger side).

 

buy this stuff called guarantee pass deq.. u can find it at shucks.. it works wonders!

 

Thanks all, for the advice. I had already tried everything you guys said except for using the GUARANTEE PASS stuff, which will be a last resort. I also have not checked the ACV valve, I see no point in checking this because all it does is allow air to pass through the line to the 5/6 port stuff, why would that cause a problem at idle? I know that my ports work fine, i have checked them with putting grease on the shaft and after driving it above 3800rpm the grease has been moved. I also feel the boost given.
So if i dont need to check this ACV valve, then all that is left is adjusting the idle air fuel mix, which is where exactly? and how do i know if i am runnin it too lean etc. Any instructions you guys got for me?
thanks alot,
Luke