failed smog again
Thread Starter
Instructor
Joined: Jul 2011
Posts: 110
Likes: 0
From: Weaverville California
failed smog again
I replaced the opti spark, plug wires and plugs on my 93 LT1. It failed smog with high CO%. I ended up having the injectors rebuilt and they found one stuck open, dumping lots of fuel. So I reinstalled them and thought it was good to go. The car failed smog again this time higher CO%. It seems there is a miss in the engine, could this be bad cats. Any ideas will help. I also did a datalog and bought a burn2 and chip, I cant get the file to open. This sucks
Thread Starter
Instructor
Joined: Jul 2011
Posts: 110
Likes: 0
From: Weaverville California
I have removed all of the mods that I know of 52mm throttle body with stock 48 mm, adjustable fuel pressure reg with stock. I thought there may be a cam but the map kpa does not indicate that. It failed at idle only. Dont know about the egr valve.
Team Owner
Joined: Aug 2005
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From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
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http://forums.corvetteforum.com/c4-t...wont-smog.html
I think your hot cam may be too much for California smog levels. Last time I smogged Betty Boop she barely pass and that one is stock.
I think your hot cam may be too much for California smog levels. Last time I smogged Betty Boop she barely pass and that one is stock.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
Ask the smog station what the max idle rpm can be. It's usually 1000 rpm. Burn a new chip with the idle speed set to 925. That should get you to pass. Go home, reinstall the prior chip and enjoy the drive.
Team Owner
Joined: Aug 2005
Posts: 34,988
Likes: 515
From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09 thru '20
This was The Ghost's smog two years ago. I'm not sure if there is a RPM limit.
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Melting Slicks
Joined: Jan 2009
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From: folsom california
In your previous thread, your idle RPM was 709; great for the street but which seems way low for a smog test; my car normally idles around 750 rpm, but for the at idle portion of the test, the smog tech stepped on the accelerator and held it at 1293 rpm (measured CO at 1293 rpm = 0.19%); The Ghost was tested at 1265 rpm. Did your car fail at idle, and if so, at what rpm was your (@ idle) retest done ?
Team Owner
Joined: Aug 2005
Posts: 34,988
Likes: 515
From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09 thru '20
In your previous thread, your idle RPM was 709; great for the street but which seems way low for a smog test; my car normally idles around 750 rpm, but for the at idle portion of the test, the smog tech stepped on the accelerator and held it at 1293 rpm (measured CO at 1293 rpm = 0.19%); The Ghost was tested at 1265 rpm. Did your car fail at idle, and if so, at what rpm was your (@ idle) retest done ?
