elliminate AIR and pass emissions
Thread Starter
Racer
Joined: Sep 2004
Posts: 258
Likes: 0
From: Coram NY
elliminate AIR and pass emissions
With the installation of an MSD 6A in my 86, can I elliminate the AIR
system and be able to pass emissions (NY Long Island) I have
high CO readings.
Thanks,
Tom
system and be able to pass emissions (NY Long Island) I have
high CO readings.
Thanks,
Tom
Racer
Joined: May 2006
Posts: 293
Likes: 0
The MSD won't make one ounce of difference. High CO is because of a rich mixture. Spark isn't an issue. Even if you had high HCs, which is unburned fuel, the (any) ignition system isn't going to develop any more voltage than necessary to jump the plug gap. The stock HEI is capable of making more voltage than all but a heavily modified L98 could ever need.
Thread Starter
Racer
Joined: Sep 2004
Posts: 258
Likes: 0
From: Coram NY
The MSD won't make one ounce of difference. High CO is because of a rich mixture. Spark isn't an issue. Even if you had high HCs, which is unburned fuel, the (any) ignition system isn't going to develop any more voltage than necessary to jump the plug gap. The stock HEI is capable of making more voltage than all but a heavily modified L98 could ever need.
inspection and give me a better running car.
But I need to get through emissions, this is such a drag!
Tom
Team Owner
Joined: Aug 2000
Posts: 40,156
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From: San Pedro CA
Remove the AIR tubes to the exhaust manifolds. That should solve your problem.
MSD is only going to mask the problem. It sounds like the bad air valves are on all the time.
I have 1987 air valves if they will work for you. I don't remember how the 1986 system looks/works.
MSD is only going to mask the problem. It sounds like the bad air valves are on all the time.
I have 1987 air valves if they will work for you. I don't remember how the 1986 system looks/works.
Safety Car
Joined: Nov 2004
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From: The Pines South Jersey
the only difference should be the egr tube - the rest of the emissions stuff on top is the same
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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MSD will not affect whether it will pass if its in good tune already.
AIR only really affects the emissions out the pipe when the engine is cold.
AIR only really affects the emissions out the pipe when the engine is cold.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
correct, but if the valve is faulty, it could be pumping additional air into the exhaust, causing the computer to overly richen the mixture.
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Racer
Joined: May 2006
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Originally Posted by tdr1919
I was told by the shop doing my inspection that he has installed MSD units in cars failing High CO and the MSD helped the burn and these cars passed.
Thread Starter
Racer
Joined: Sep 2004
Posts: 258
Likes: 0
From: Coram NY
So if you are buying his scam story, why are you asking us? I gave you the straight scoop. There are an awful lot of cars that pass emissions without MSDs. If you have a diverter valve problem, make sure the A.I.R. air is not directed into the exhaust manifolds for the test. The MSD will do nothing to help your car to pass, unless the tester will "help" it pass after you spend that money with him.
I come to this forum for its valuable info, I merely stated what this mechanic told me. I am not contradicting you. I do all my own work, so he is only getting the Inspection money, I want to get through this inspection and and be out driving my car. If the MSD can help performance & gas mileage them I will be happy, but I have read where people have had reliability issues with the MSD.
Thank you,
Tom
Team Owner
Joined: Sep 2001
Posts: 62,119
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Then you will not be happy, because on a stock engine it wont do anything.
And yes, there have been several that have had reliability issues with the MSD boxes.
Thread Starter
Racer
Joined: Sep 2004
Posts: 258
Likes: 0
From: Coram NY
It sounds like you have first hand experience with the MSD box, and I am getting the impression that you do not like them, or is it that it is really only for a "modified" performance engine.
I kind of thought that it would be a building block for future improvements on the engine.
Your thoughts.
Tom
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
One ignition step you can take to clean up the exhaust is to do the cut-back spark plug mod, details on my site.
This will give a little more complete charge burn which also nets a little power gain.
This will give a little more complete charge burn which also nets a little power gain.
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
I was told by the shop doing my inspection that he has installed MSD units in cars failing High CO and the MSD helped the burn and these cars passed. As I found my AIR solenoids are bad (and it looks as if I can only ge them through GM) I believe this is pumping air into the exhaust and making the ECM richen the mixture. I thought the MSD along with stopping the AIR from being injected, would get me through
inspection and give me a better running car.
But I need to get through emissions, this is such a drag!
Tom
inspection and give me a better running car.
But I need to get through emissions, this is such a drag!
Tom
Racer
Joined: May 2006
Posts: 293
Likes: 0
Originally Posted by tdr1919
C4,
I come to this forum for its valuable info, I merely stated what this mechanic told me. I am not contradicting you.If the MSD can help performance & gas mileage them I will be happy, but I have read where people have had reliability issues with the MSD.
Thank you,
Tom
I come to this forum for its valuable info, I merely stated what this mechanic told me. I am not contradicting you.If the MSD can help performance & gas mileage them I will be happy, but I have read where people have had reliability issues with the MSD.
Thank you,
Tom
Reliability issues aside, a high performance ignition system isn't going to improve your emissions problems.
Just because a guy wears the uniform of a parts guy or a mechanic, doesn't necessarily mean that he knows how things work. HERE is a prime example.
Last edited by C4Techie; Feb 27, 2007 at 11:24 AM.