Possible to run air pump w/o ACV?
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Joined: Mar 2013
Posts: 38
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From: Japan
Possible to run air pump w/o ACV?
The single turbo set up im doing involves pulling off the air pump, but keeping minimal lines on so I can throw it on for a day to pass emissions. The thing is that i'd like to remove as much unneccessary bits under the UIM as possible to keep things simple. The ACV seems unneccesary if the air pump is only going to be on for 5 minutes every 2 yrs to pass emissions.
As far as my understanding goes, the ACV is there to activate/deactivate the pump since it is only on until 3800 rpm. Would it be possible to remove the ACV, but still have the air pump on there, rendering it running 100% of the time ... basically running a line directly from the air pump to the cat?
As far as my understanding goes, the ACV is there to activate/deactivate the pump since it is only on until 3800 rpm. Would it be possible to remove the ACV, but still have the air pump on there, rendering it running 100% of the time ... basically running a line directly from the air pump to the cat?
Thread Starter
Junior Member
Joined: Mar 2013
Posts: 38
Likes: 0
From: Japan
Well, I had the same problem recently, went non-sequential with a standalone ecu so the ACV valve had to go, but the car still needed to pass an emissions test.
The solution of routing the air pump to the cat might work, but it isn't ideal. Check out this topic:
https://www.rx7club.com/3rd-generati...blems-1011866/
It clearly shows that most of the time air from the air pump is directed to the air ports in the exhaust channels in the rotor housings, NOT the cat. It's only partly directed to the cat in certain conditions. What I did was remove the stock ACV and machine an aluminium piece that fits where the ACV valve went which directs about 90% of the air to the air port, and about 10% of the air to the cat. If your interested I can make a picture of the part I machined.
Nice part about this is that because the ACV replacement piece is underneath the UIM everything still looks 100% stock, and emission values are similar to a stock setup aswell.
This worked very well, the car still passes emmissions just fine. I'm using the standalone ecu to switch the air pump on and off, which works fine! If your on a standalone ecu, remember to switch the air pump off at all times during tuning (or when the ecu is autotuning), the airpump throws the wideband AF reading off a LOT.
The solution of routing the air pump to the cat might work, but it isn't ideal. Check out this topic:
https://www.rx7club.com/3rd-generati...blems-1011866/
It clearly shows that most of the time air from the air pump is directed to the air ports in the exhaust channels in the rotor housings, NOT the cat. It's only partly directed to the cat in certain conditions. What I did was remove the stock ACV and machine an aluminium piece that fits where the ACV valve went which directs about 90% of the air to the air port, and about 10% of the air to the cat. If your interested I can make a picture of the part I machined.
Nice part about this is that because the ACV replacement piece is underneath the UIM everything still looks 100% stock, and emission values are similar to a stock setup aswell.
This worked very well, the car still passes emmissions just fine. I'm using the standalone ecu to switch the air pump on and off, which works fine! If your on a standalone ecu, remember to switch the air pump off at all times during tuning (or when the ecu is autotuning), the airpump throws the wideband AF reading off a LOT.
Well, I had the same problem recently, went non-sequential with a standalone ecu so the ACV valve had to go, but the car still needed to pass an emissions test.
The solution of routing the air pump to the cat might work, but it isn't ideal. Check out this topic:
https://www.rx7club.com/3rd-generati...blems-1011866/
It clearly shows that most of the time air from the air pump is directed to the air ports in the exhaust channels in the rotor housings, NOT the cat. It's only partly directed to the cat in certain conditions. What I did was remove the stock ACV and machine an aluminium piece that fits where the ACV valve went which directs about 90% of the air to the air port, and about 10% of the air to the cat. If your interested I can make a picture of the part I machined.
Nice part about this is that because the ACV replacement piece is underneath the UIM everything still looks 100% stock, and emission values are similar to a stock setup aswell.
This worked very well, the car still passes emmissions just fine. I'm using the standalone ecu to switch the air pump on and off, which works fine! If your on a standalone ecu, remember to switch the air pump off at all times during tuning (or when the ecu is autotuning), the airpump throws the wideband AF reading off a LOT.
The solution of routing the air pump to the cat might work, but it isn't ideal. Check out this topic:
https://www.rx7club.com/3rd-generati...blems-1011866/
It clearly shows that most of the time air from the air pump is directed to the air ports in the exhaust channels in the rotor housings, NOT the cat. It's only partly directed to the cat in certain conditions. What I did was remove the stock ACV and machine an aluminium piece that fits where the ACV valve went which directs about 90% of the air to the air port, and about 10% of the air to the cat. If your interested I can make a picture of the part I machined.
Nice part about this is that because the ACV replacement piece is underneath the UIM everything still looks 100% stock, and emission values are similar to a stock setup aswell.
This worked very well, the car still passes emmissions just fine. I'm using the standalone ecu to switch the air pump on and off, which works fine! If your on a standalone ecu, remember to switch the air pump off at all times during tuning (or when the ecu is autotuning), the airpump throws the wideband AF reading off a LOT.
could you send me a pic of what you did?
Joined: Mar 2001
Posts: 31,835
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From: https://www2.mazda.com/en/100th/
Well, I had the same problem recently, went non-sequential with a standalone ecu so the ACV valve had to go, but the car still needed to pass an emissions test.
The solution of routing the air pump to the cat might work, but it isn't ideal. Check out this topic:
https://www.rx7club.com/3rd-generati...blems-1011866/
It clearly shows that most of the time air from the air pump is directed to the air ports in the exhaust channels in the rotor housings, NOT the cat. It's only partly directed to the cat in certain conditions. What I did was remove the stock ACV and machine an aluminium piece that fits where the ACV valve went which directs about 90% of the air to the air port, and about 10% of the air to the cat. If your interested I can make a picture of the part I machined.
Nice part about this is that because the ACV replacement piece is underneath the UIM everything still looks 100% stock, and emission values are similar to a stock setup aswell.
This worked very well, the car still passes emmissions just fine. I'm using the standalone ecu to switch the air pump on and off, which works fine! If your on a standalone ecu, remember to switch the air pump off at all times during tuning (or when the ecu is autotuning), the airpump throws the wideband AF reading off a LOT.
The solution of routing the air pump to the cat might work, but it isn't ideal. Check out this topic:
https://www.rx7club.com/3rd-generati...blems-1011866/
It clearly shows that most of the time air from the air pump is directed to the air ports in the exhaust channels in the rotor housings, NOT the cat. It's only partly directed to the cat in certain conditions. What I did was remove the stock ACV and machine an aluminium piece that fits where the ACV valve went which directs about 90% of the air to the air port, and about 10% of the air to the cat. If your interested I can make a picture of the part I machined.
Nice part about this is that because the ACV replacement piece is underneath the UIM everything still looks 100% stock, and emission values are similar to a stock setup aswell.
This worked very well, the car still passes emmissions just fine. I'm using the standalone ecu to switch the air pump on and off, which works fine! If your on a standalone ecu, remember to switch the air pump off at all times during tuning (or when the ecu is autotuning), the airpump throws the wideband AF reading off a LOT.
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