there seems to be some confusion as to how the airpump/ air control valve system / cats function on the mazda rotary cars. we'll look at each part seperately.



egr: the s4's have it, it is used during cruising only, it is off at idle and high load. it is also small, and will have little effect on the idle of the car when tested the "normal" way



air pump: it pumps air into the acv



air control valve: its job is to take the air pump air and distribute it. between idle and 2500-3200 (it varies car to car), the air pump air is supplied to the exhaust ports. over 3200 rpms it is vented out to the atmosphere. there is certain conditions when air is supplied to the main cat, but i'm not sure when they dont specifiy in the books. the acv is run with 2 vacuum diaphrams, 2 solenoids, the ecu and you guessed it the TPS. if the tps is bad the acv will not work right.



tps: important smog part, it runs the acv



main cat: the cat is responsible for cleaning up the exhaust gas/airpump air mix. it basically uses heat to do so. in order for the main cat to work correctly it need the correct amount of unburned gas/burned gas, the cats like to be a little on the rich side, if its too lean it wont "turn on"





mike

 

Thanks!

 

good info mike

 

yes i agree

 

but removing your emissions stuff doesn not include removing the TPS, correct?

 

No it doesn't. The ECU still needs the TPS.

 

that's what I thought, just clarifying