Failed Emissions Test...HELP!
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Instructor
Joined: Aug 2003
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From: Soddy Daisy TN
Failed Emissions Test...HELP!
Hey guys. 1985 Coupe. Tennesse, (Hamilton County), has started emissions testing this year and I failed my first try yesterday. I have a brand new cat installed and I have had the car on a scanner. I do not throw any codes and the car runs great. But the numbers yesterday were:
CO2-.59 with a limit of 1.20
HC- 2818 with a limit of 220. WOW!!!
When I showed this to my mechanic he said I should be blowing black smoke out of the pipes which I do not. I have an adjustable fuel reg and my pressure is set at 34- 35 pounds. I have 24# injectors with a mild cam and aluminum heads. Do I need to reduce my fuel pressure? If yes how low should I go? What else should I do to get the numbers down? And is it possible for my CO2 to be that low and HC that high? I don't trust the test since a friend of mine rolled in there in a S-10 pickup and it tested "0" emissions. How about that! Anyway I would sure appreciate some direction from some of the expers. Thanks, Troy.
CO2-.59 with a limit of 1.20
HC- 2818 with a limit of 220. WOW!!!
When I showed this to my mechanic he said I should be blowing black smoke out of the pipes which I do not. I have an adjustable fuel reg and my pressure is set at 34- 35 pounds. I have 24# injectors with a mild cam and aluminum heads. Do I need to reduce my fuel pressure? If yes how low should I go? What else should I do to get the numbers down? And is it possible for my CO2 to be that low and HC that high? I don't trust the test since a friend of mine rolled in there in a S-10 pickup and it tested "0" emissions. How about that! Anyway I would sure appreciate some direction from some of the expers. Thanks, Troy.
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
You need a scan tool to see what's up inside, ie what the ECM is seeing and what it it doing. If none is available, jumper ALDL pins A&B (upper right) with a paper clip, start the engine and watch the SES flashes. After a minute or so they should slow from 2Hz to 1Hz as the ECM goes into closed loop mode. If the A/F ratio is OK the On/Off durations should be of equal duration; longer On = rich & longer Off = lean.
Does your '85 still have all the emissions equipment?
Is the ECM throwing any codes?
How old is the main cat?
Does it have pre-cats in the front Y?
Does your '85 still have all the emissions equipment?
Is the ECM throwing any codes?
How old is the main cat?
Does it have pre-cats in the front Y?
Pro
Joined: Feb 2005
Posts: 632
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From: Harrisburg, PA 86 Vert w/ 89 wheels
Originally Posted by drumboytroy
Hey guys. 1985 Coupe. Tennesse, (Hamilton County), has started emissions testing this year and I failed my first try yesterday. I have a brand new cat installed and I have had the car on a scanner. I do not throw any codes and the car runs great. But the numbers yesterday were:
CO2-.59 with a limit of 1.20
HC- 2818 with a limit of 220. WOW!!!
When I showed this to my mechanic he said I should be blowing black smoke out of the pipes which I do not. I have an adjustable fuel reg and my pressure is set at 34- 35 pounds. I have 24# injectors with a mild cam and aluminum heads. Do I need to reduce my fuel pressure? If yes how low should I go? What else should I do to get the numbers down? And is it possible for my CO2 to be that low and HC that high? I don't trust the test since a friend of mine rolled in there in a S-10 pickup and it tested "0" emissions. How about that! Anyway I would sure appreciate some direction from some of the expers. Thanks, Troy.
CO2-.59 with a limit of 1.20
HC- 2818 with a limit of 220. WOW!!!
When I showed this to my mechanic he said I should be blowing black smoke out of the pipes which I do not. I have an adjustable fuel reg and my pressure is set at 34- 35 pounds. I have 24# injectors with a mild cam and aluminum heads. Do I need to reduce my fuel pressure? If yes how low should I go? What else should I do to get the numbers down? And is it possible for my CO2 to be that low and HC that high? I don't trust the test since a friend of mine rolled in there in a S-10 pickup and it tested "0" emissions. How about that! Anyway I would sure appreciate some direction from some of the expers. Thanks, Troy.
DAAMMMMMMMMMNNNNNNNN!!!!!!!!!!!!!
I was gonna get a summer home in Tennessee when I'm insanely rich and register all my cars there but my plan is going straight down the hole if they start taking inspection seriously.
You must know your state has a rep for lax inspections, right?
Race Director
Joined: Sep 2000
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From: The Top of Utah
Time for a new mechanic. Black smoke is a sign of a very rich mixture. If the test results are to be believed, your A/F mixture is good. Your CO2 tells you that. You can confirm by readings from your scanner. HCs (Hydro-Carbons) are UNburned fuel. That is an amazingly high number. Oil that needs to be changed and cause high HCs. Gasoline that is diluted in the oil can have vapors enter the combustion process through the PCV valve. Any misfire can cause high HCs. Bad plugs, wires, EGR valve, even a lean mixture and cause misfires. There are any number of other sources of unburned fuel.
RACE ON!!!
RACE ON!!!
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by drumboytroy
Does your '85 still have all the emissions equipment? NO
Is the ECM throwing any codes? NO
How old is the main cat? Brand New
Does it have pre-cats in the front Y? NO
Is the ECM throwing any codes? NO
How old is the main cat? Brand New
Does it have pre-cats in the front Y? NO
RACE ON!!!
Thread Starter
Instructor
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From: Soddy Daisy TN
Yes I am aware of that and there are a lot of pissed off people now because of the changes. There is a lot of political BS here in Chattanooga. I understand that all of the plots of land that al the emission stations are built on here in Hamilton County are owned by the last Mayor of the city. (That's the word around town...don't have proof yet. Also another strange thing is that the emissions testing facilities ONLY ACCEPT CASH! $10 for the test in cash and nothing larger than a 20 dollar bill allowed. Sounds like funny business to me. I thought this was done by the EPA. Never heard of a Govt. agency dealing only in cash except in the 3rd world countries.
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Thread Starter
Instructor
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From: Soddy Daisy TN
Originally Posted by 65Z01
What emissions equipment is missing?
If the AIR system has been eliminated you may need to replace it and hook it up to the cat to help with HCs.
If the AIR system has been eliminated you may need to replace it and hook it up to the cat to help with HCs.
I have removed all of the AIR systm and the hedders on the car now do not have provisions for the air system or the cat. Now that i have all of these nice new upgrades on my car over the last 3 years they start emissions tests. All the old stuff is long gone.
Thread Starter
Instructor
Joined: Aug 2003
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From: Soddy Daisy TN
Originally Posted by CFI-EFI
Time for a new mechanic. Black smoke is a sign of a very rich mixture. If the test results are to be believed, your A/F mixture is good. Your CO2 tells you that. You can confirm by readings from your scanner. HCs (Hydro-Carbons) are UNburned fuel. That is an amazingly high number. Oil that needs to be changed and cause high HCs. Gasoline that is diluted in the oil can have vapors enter the combustion process through the PCV valve. Any misfire can cause high HCs. Bad plugs, wires, EGR valve, even a lean mixture and cause misfires. There are any number of other sources of unburned fuel.
RACE ON!!!
RACE ON!!!
Race Director
Joined: Sep 2000
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From: The Top of Utah
Certificates and accolades aside, A rich mixture still causes high CO2 readings. HCs are unburned fuel. I'm surprised if a "Mater Mechanic and Tecnician" isn't aware of that.
I wasn't suggesting that you didn't maintain your car. I was merely listing some of the common causes of high HC readings. If your car is so well maintained, why did it fail? My old '78 GMC with a 400 quadrajet carbed engine, no cats, no smog pump, and no EGR, passes YOUR test.
RACE ON!!!
I wasn't suggesting that you didn't maintain your car. I was merely listing some of the common causes of high HC readings. If your car is so well maintained, why did it fail? My old '78 GMC with a 400 quadrajet carbed engine, no cats, no smog pump, and no EGR, passes YOUR test.
RACE ON!!!
Thread Starter
Instructor
Joined: Aug 2003
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From: Soddy Daisy TN
Originally Posted by CFI-EFI
Certificates and accolades aside, A rich mixture still causes high CO2 readings. HCs are unburned fuel. I'm surprised if a "Mater Mechanic and Tecnician" isn't aware of that.
I wasn't suggesting that you didn't maintain your car. I was merely listing some of the common causes of high HC readings. If your car is so well maintained, why did it fail? My old '78 GMC with a 400 quadrajet carbed engine, no cats, no smog pump, and no EGR, passes YOUR test.
RACE ON!!!
I wasn't suggesting that you didn't maintain your car. I was merely listing some of the common causes of high HC readings. If your car is so well maintained, why did it fail? My old '78 GMC with a 400 quadrajet carbed engine, no cats, no smog pump, and no EGR, passes YOUR test.
RACE ON!!!
My point exactly! I can't answer that question yet. Thanks man.
Le Mans Master
Joined: Dec 2000
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From: San Diego, Ca
Can't imagine it's running very well with those HC's - are you sure on the #? With that much unburned fuel it's hardly making all the power it can. I'd guess that the ECM thinks it's lean, so it's adding fuel. A scan would help tell the story, but since you eliminated the smog pump, I'd make sure the headers are sealed up nice and tight - if they're sucking air, the O2 will be lean and the ECM will add fuel. Ditto for vacuum, runner, plenum leaks and everything else that CFI-EFI has mentioned. I'm also suspect of the 24 lb injectors squirting at 34 psi - too little fuel and it sets the stage for a lean miss. Did you log any data before you made the changes? Always nice to have something to compare, but if you don't, I'd hook up a scanner and see where the BLM's are now.
Thread Starter
Instructor
Joined: Aug 2003
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From: Soddy Daisy TN
Originally Posted by SunCr
Can't imagine it's running very well with those HC's - are you sure on the #? With that much unburned fuel it's hardly making all the power it can. I'd guess that the ECM thinks it's lean, so it's adding fuel. A scan would help tell the story, but since you eliminated the smog pump, I'd make sure the headers are sealed up nice and tight - if they're sucking air, the O2 will be lean and the ECM will add fuel. Ditto for vacuum, runner, plenum leaks and everything else that CFI-EFI has mentioned. I'm also suspect of the 24 lb injectors squirting at 34 psi - too little fuel and it sets the stage for a lean miss. Did you log any data before you made the changes? Always nice to have something to compare, but if you don't, I'd hook up a scanner and see where the BLM's are now.
I just made an appointment for Saturday to get her scanned. And suprisingly she runs pretty strong. Maybe when all this smoke clears and we get her right, she'll be even stronger. Thanks man.
Race Director
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From: The Top of Utah
Originally Posted by drumboytroy
My point exactly! I can't answer that question yet. Thanks man.
RACE ON!!!
Race Director
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From: N. Alabama
Originally Posted by illinest
DAAMMMMMMMMMNNNNNNNN!!!!!!!!!!!!!
I was gonna get a summer home in Tennessee when I'm insanely rich and register all my cars there but my plan is going straight down the hole if they start taking inspection seriously.
You must know your state has a rep for lax inspections, right?
I was gonna get a summer home in Tennessee when I'm insanely rich and register all my cars there but my plan is going straight down the hole if they start taking inspection seriously.
You must know your state has a rep for lax inspections, right?
Melting Slicks
Joined: Nov 2002
Posts: 2,471
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From: 1993 Quasar Blue 'vert Scottsdale AZ
Originally Posted by illinest
DAAMMMMMMMMMNNNNNNNN!!!!!!!!!!!!!
I was gonna get a summer home in Tennessee when I'm insanely rich and register all my cars there but my plan is going straight down the hole if they start taking inspection seriously.
You must know your state has a rep for lax inspections, right?
I was gonna get a summer home in Tennessee when I'm insanely rich and register all my cars there but my plan is going straight down the hole if they start taking inspection seriously.
You must know your state has a rep for lax inspections, right?
