Can you pass emisions with no air pump?
#1
~~~~~~~~~~~~~~~~~~~~~~~
Thread Starter
Join Date: May 2001
Location: Pittsburgh, PA
Posts: 1,594
Likes: 0
Received 0 Likes
on
0 Posts
Can you pass emisions with no air pump?
I swap my exhaust system once a year for the test and was wondering if just the stock cat is good enough to pass. My buddy who helps me out with the test only uses one tail pipe, so that helps alot. I know the air pump saves the life of the cat but I only need it to work for one hour a year. So; what's the deal here?
#5
HAILERS
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 22 Likes
on
20 Posts
The acv does supply fresh air to the cat thru the split air pipe, but the acv does more than that. At idle the *switching diaphram* inside the acv has a vacuum on it. With a vacuum on it , fresh air is sent to the *port* air passage of the acv. That leads into the housings where it exits a half inch hole next to the rear exaust port and mixes with the exaust air for emissions purposes. Theres also the AAV inside the acv that opens , I believe , during high vacuum in the intake manifold, and when it opens lets fresh air into the intake(best I can tell by the diagram which is flaky) to prevent backfire. Some say the split air is used to cool the catalytic converter. Thats an explanation I have serious doubts about. Coulda left that last sentence off, but I thought I could provoke a better answer out of someone. And by the way, if you own a turbo with the original acv on it, I'll bet money that its a crispy critter and does not work. The turbo heat seems to eat those things alive.
#7
SOLD THE RX-7!
Join Date: Mar 2001
Location: Vancouver, BC, Canada
Posts: 7,451
Likes: 0
Received 0 Likes
on
0 Posts
the cat runs hoter with the air pump, that's it's job. the hoter the cat the lower the emissions, the air is not cooling the cat, it's mixing with the unburnt fuel and burning, burning causes heat.
yes running the air pump straight to the cat will work great as it will make the cat even hotter, but don't leave it for very long, the cat will get way to hot and melt. like stick it on before you go test, and remove it as soon as you get home.
yes running the air pump straight to the cat will work great as it will make the cat even hotter, but don't leave it for very long, the cat will get way to hot and melt. like stick it on before you go test, and remove it as soon as you get home.
Trending Topics
#8
Rotary Enthusiast
iTrader: (17)
Join Date: Feb 2001
Location: Pluto
Posts: 878
Likes: 0
Received 0 Likes
on
0 Posts
Hey Hailers you are dead right about the ACV,it's the switching valve diaphragm which usually fries first.There is a cheap solution--it is possible to make the switching valve and diaphragm from the N/A motor fit the turbo--about 10 mins worth of metal shaping.
As far as split air versus port air is concerned,according to Mazda,port air is supplied up to 3600rpm with middling throttle opening,with a heavier throttle opening air is switched to split air.Here in Ontario they use the ASM2525 emission test(25% load 2000-2500rpm)which means you have to make it on port air.As you say at idle it is all port air.
I haven't tried it but I would think hooking the air pump to the cat would be a recipe for disaster--kind of loke a cutting torch in there!
As far as split air versus port air is concerned,according to Mazda,port air is supplied up to 3600rpm with middling throttle opening,with a heavier throttle opening air is switched to split air.Here in Ontario they use the ASM2525 emission test(25% load 2000-2500rpm)which means you have to make it on port air.As you say at idle it is all port air.
I haven't tried it but I would think hooking the air pump to the cat would be a recipe for disaster--kind of loke a cutting torch in there!
#9
HAILERS
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 22 Likes
on
20 Posts
SixRotors....thanks for the tip on the switching diaphram. I've been more or less working on doing what you said except I've got a couple of acv off 82-83????? . There is a ear that I had to cut off on the first one I tried so it would fit. Unfortualtly that one has a minor leak in the diaphram so it didn't quite work out and I dropped that project right now. I'll be a little more motivated next Sept when emissions are due on the turbo.
And also thanks for the info on the purpose of the split air going to the catalytic converter. So its to aid in the catalyst in doing its job by adding some oxygen to the burning process. Sounds good to me.
And also thanks for the info on the purpose of the split air going to the catalytic converter. So its to aid in the catalyst in doing its job by adding some oxygen to the burning process. Sounds good to me.
Last edited by HAILERS; 01-17-02 at 04:42 PM.
#10
Junior Member
Join Date: Nov 2003
Location: Zelienolple, PA
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
One other note since your from the burgh also, under PA emmission laws, before the tail pipe test can be perfomed it must be visually inspected for all the components being there, to sum up no air pump = failed emissions inspection before the tail pipe test is performed.
Thread
Thread Starter
Forum
Replies
Last Post
Skeese
Adaptronic Engine Mgmt - AUS
65
03-28-17 03:30 PM
12abridgeport
1st Generation Specific (1979-1985)
2
08-17-15 06:28 PM