Corvette Running Rich
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
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From: Houston Texas
Corvette Running Rich
My god has it been a while!! Well lets start with this, over the last few months I dropped the exhaust, gutted the precats, replaced the main cat (magnaflow), replaced the 02 sensor, and welded in a pair of cutouts (ill post pics tomorrow or so). Well thats pretty much it. Tomorrow should be the big day that everything is bolted togeather and it sees the road. I have started it a few times in the garage (never really more then a few minutes) and I can smell a heavy scent of gas as if it rich (it is fairly cold at this point in time down here).
So here are my questions.
1. does it seem like im running rich? or the car just hasnt reached optimum temp.
2. Prior to the list of fixes the car was jerking violently at idle (in 1st gear, clutch out), almost hunting up and down for proper idle after running for a while. Im hoping it was just running hot due to a bad cat. Is it possiable?
3. Is there any harm done with disconnecting the air line that runs to the main cat? from what I hear that have delete kits all togeather for that air line.
I really hope you guys be understanding about all the questions, im just trying to get this car running. All help is appreciated. BTW its an 1989 corvette.
So here are my questions.
1. does it seem like im running rich? or the car just hasnt reached optimum temp.
2. Prior to the list of fixes the car was jerking violently at idle (in 1st gear, clutch out), almost hunting up and down for proper idle after running for a while. Im hoping it was just running hot due to a bad cat. Is it possiable?
3. Is there any harm done with disconnecting the air line that runs to the main cat? from what I hear that have delete kits all togeather for that air line.
I really hope you guys be understanding about all the questions, im just trying to get this car running. All help is appreciated. BTW its an 1989 corvette.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Get 'er fired up to closed loop temp and see if the symptom goes away.
The air line to the cat helps to heat it up. Shouldn't be a factor once she's hot.
The air line to the cat helps to heat it up. Shouldn't be a factor once she's hot.
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
dont think the pics of the cutouts made it through, but here is a link.
http://img838.imageshack.us/g/img0001gd.jpg/
http://img838.imageshack.us/g/img0001gd.jpg/
Drifting
Joined: Oct 2003
Posts: 1,594
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From: CALGARY ab
they do run rich when cold,, have you thought of removing the entire smog/egr stuff? it easy to do.. : check this out
JUST INSTALLED AIR PUMP ELIMINATOR
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Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
good job!! well done
they do run rich when cold,, have you thought of removing the entire smog/egr stuff? it easy to do.. : check this out
JUST INSTALLED AIR PUMP ELIMINATOR
they do run rich when cold,, have you thought of removing the entire smog/egr stuff? it easy to do.. : check this out
JUST INSTALLED AIR PUMP ELIMINATOR
..WW
Last edited by WW7; Jan 23, 2011 at 08:24 AM.
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
Hey I have another question back to the air pump deal, whats its purpose? Does it pump air into the cat so you can pass inspection, cause this year it took him twice as longe to get it to pass. The guy had to restart 2 or 3 times, and that was with that line unhooked.
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
good job!! well done
they do run rich when cold,, have you thought of removing the entire smog/egr stuff? it easy to do.. : check this out
JUST INSTALLED AIR PUMP ELIMINATOR
they do run rich when cold,, have you thought of removing the entire smog/egr stuff? it easy to do.. : check this out
JUST INSTALLED AIR PUMP ELIMINATOR
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Hey I have another question back to the air pump deal, whats its purpose? Does it pump air into the cat so you can pass inspection, cause this year it took him twice as longe to get it to pass. The guy had to restart 2 or 3 times, and that was with that line unhooked.
I would suspect the running rich problem is related to your new set up on the exhaust. If the O2s are not heating as before, and the ECM expected certain conditions per the original exhaust, it may be adjusting the A/F ratio to rich. A tune may be required to adjust the fuel trim (BLM) numbers in relation to the new exhaust system.
Thread Starter
Instructor
Joined: Dec 2009
Posts: 236
Likes: 0
From: Houston Texas
All these air pumps and its associated pluming is to cut down emissions when the engine is cold. When it gets hot on my 94 the electric air pump does not even run. So when it's hot it should not be a factor as JrRifleCoach indicated. I don’t know the exact pluming of the 89 but there is probably a system that shuts down the pump action.
I would suspect the running rich problem is related to your new set up on the exhaust. If the O2s are not heating as before, and the ECM expected certain conditions per the original exhaust, it may be adjusting the A/F ratio to rich. A tune may be required to adjust the fuel trim (BLM) numbers in relation to the new exhaust system.
I would suspect the running rich problem is related to your new set up on the exhaust. If the O2s are not heating as before, and the ECM expected certain conditions per the original exhaust, it may be adjusting the A/F ratio to rich. A tune may be required to adjust the fuel trim (BLM) numbers in relation to the new exhaust system.
Race Director
Joined: Apr 2003
Posts: 17,699
Likes: 1,667
From: moraga ca
Hey I have another question back to the air pump deal, whats its purpose? Does it pump air into the cat so you can pass inspection, cause this year it took him twice as longe to get it to pass. The guy had to restart 2 or 3 times, and that was with that line unhooked.
