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Am I going to burn the valves?

2K views 9 replies 3 participants last post by  TNCowboyPRCA 
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#1 ·
On my '83, when the 400 was put in all of the original emissions stuff was put back on. I don't have cats anymore, but I've still got the air pump and related hardware connected to the exhaust manifolds. I was told that removing it and running it would burn the valves. Is there any truth to this?

I thought I'd done my research well enough and everyone else I talked to said they'd done it at some time or other.
 
#2 ·
You shouldnt hurt anything, its always been a popular but somewhat illegal thing to remove the "cats" and put in a "test pipe". As long as you dont have to pass emissions
 
#3 ·
there should be no real difference. unless there are other motor problems, running the A.I.R. system should not cause problems.

My question is, why run it at all? Your just robbing yourself of HP by running that air pump off the crank. There is a/should be a 1 way valve between the pump and exhaust. So long as that is working fine, you can just remove the pump. The exhaust will still be closed off, but for the tail pipe.

As a side note, if you buy a truck with the A.I.R pump ceased and the belt removed, don't just replace the pump. Replace the one way as well. Often people replace pump after pump not realizing that the one way valve is bad and is the cause of pump failure.
 
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#4 ·
From all of the posts I've read at CK5 and elsewhere, everyone agrees it's safe to take off. The air pump in-and-of-itself doesn't rob that much power at all, removing it is for uncluttering purposes. Like me. So I will also be removing the tubes off the manifolds, those are my main gripe. I wouldn't mind finding a set of manifolds (not headers) without the holes in them. I also see a few things in the way the vacuum hoses are routed in general that I will tinker with. Things that have over the years have been done...with a certain amount of creativity.

The thing was, when I brought this up with my dad (previous and original owner of truck) he said that his mechanic told him the pump was necessary. Otherwise my dad himself would've removed it long time ago; he too doesn't like unnecessary crap hanging off the engine.
 
#5 ·
you should be fine without it. i have a car, pump is dead but still there. no issues. if you were running rich, you would have a problem. that adds extra air to the unburned fuel heating up the manifold.

there is a chance those lines into the manifold are pipe thread, or another standard thread. so, you can put things in there to clog them up. i've seen it done. there may even be a GM part number for it. b/c not all cars/trucks used those A.I.R pumps, and they may have manifolds in common.
 
#8 ·
question, i dont have the AIR system and only standard manifolds. alabama no longer has emission laws and i dont live in the city limits back home so i cut the cats. that left 4 o2 sensors homeless. 2 were pre-cat, and two were after the cats, somethin i read said i need to place o2 simulators on the back two and just leave the first two routed in the normal places. is this true, will the mpg suffer? right now ive got all 4 unconnected and no lights have flashed up.
 
#9 ·
you do need them. you should have got some kind of light. it should be triggered, unless for some other reason the computer does not go from closed to open loop.

my guess, and it is only a guess, is that the 02s are there to trigger some kind of SES light if the cats stop working. i can't think of any other reason to have them. again, just a guess. i'd remove the cats and just reinstall the 02s.

i really don't understand the o2 simulators. just because the computer needs them to work properly. i always figured GM engineers put them there for a reason, and there is not really a good reason to remove them.
 
#10 ·
from what i understand, the first one will be fine since it just knows that the air is dirtier goin into the cat, 02 sensor 2 needs to know the air is cleaner than when it entered, im guessin the o2 simulator would go on set number 2 after the cats. neither pre -set nor the after- set is connected, they just cut the wires and left them dangling, but no lights have come up. will this still affect mpg. they may have grounded the wires so that no light shows up but the computer still is affected.
 
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