Notices
Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

Exhaust backfires, running rich, poor mileage....come in! (AIR removal)

 
Old 05-29-2005, 10:38 PM
  #1  
Teching In
Thread Starter
 
Join Date: Oct 2002
Location: San Antonio, TX
Posts: 22
Default Exhaust backfires, running rich, poor mileage....come in! (AIR removal)

Guys,

I've wanted to remove the AIR system in my car for quite a while, so I decided to tackle the job this weekend. I had read this article in preparation for the job. It explains how to remove all the major components, but doesn't go into details about what to do with vaccum lines and other small parts. I took pictures of the process, so whenever you try this, you won't be as lost as I was. Without further delay, here they are:



























I should add that I was having some serious backfires through the exhaust. I suspected the AIR system may have something to do with it, but couldn't confirm. Upon removal, I found out one of the check valves was not sealing at all. They are supposed to be a one-way valve, but the passenger's side was not sealing either way. This in turn allowed fresh air to enter the manifold causing shotgun-like backfires. This problem was also tricking the O2 sensor on that bank into believing the engine was running lean, therefore advising the PCM to dump more fuel, which showed up in my last oil analysis.....it was 1.8%.....normal is 0.5% or less. My gas mileage has also been somewhat crappy lately, so this fix should definitely restore mileage back to normal.
If you are having backfires and seem to be running very rich for no apparent reason, check your check valves....they could be bad.

Hope this is of help to someone.

Rick
Last_Z is offline  
Old 05-29-2005, 11:30 PM
  #2  
TECH Enthusiast
 
Schwindj's Avatar
 
Join Date: Apr 2005
Location: Houston/Lubbock
Posts: 594
Default

where are the check valves and what exactly do they do?
Schwindj is offline  
Old 05-29-2005, 11:37 PM
  #3  
Teching In
Thread Starter
 
Join Date: Oct 2002
Location: San Antonio, TX
Posts: 22
Default

Look at picture #4. See where the nuts are on the pipe? The black saucer shaped thing? Inside there! The valves are basically one-way flaps, which allow air to go from the pump into the manifolds, but not back to the pump. I had one that wasn't sealing at all. That leak was wrecking havoc with my air/fuel ratio and causing real bad backfires.
Last_Z is offline  
Old 05-30-2005, 12:15 AM
  #4  
Teching In
 
Join Date: May 2005
Posts: 12
Default

I don't understand your problem, your car is running now right?
thatcamaroguy is offline  
Old 05-30-2005, 09:37 AM
  #5  
Teching In
Thread Starter
 
Join Date: Oct 2002
Location: San Antonio, TX
Posts: 22
Default

Originally Posted by thatcamaroguy
I don't understand your problem, your car is running now right?
Yes, the car is now running right!

The problem WAS horrible backfires through the exhaust along with an extremely rich condition. The car was running so rich that I had almost 2% fuel in my oil last time I did a Used Oil Analysis! What caused that was an open pathway (or basically a massive leak) in the exhaust system. Exhaust gases and fresh air was moving back and forth between the intake lid and the exhaust manifolds. In fact, I disconnected the hose from the lid and there was suction or vaccum, but the AIR pump was off. You simply cannot have unchecked air moving at will between intake and exhaust.
Simply put,the check valves will eventually burn up or wear out and give you lots of headaches. People who install headers get this problem almost right away; but as I found out, it isn't limited to headers only......they'll wear out on a 100% stock car as well.

Rick
Last_Z is offline  
Old 05-30-2005, 11:47 AM
  #6  
TECH Enthusiast
iTrader: (4)
 
General Jack's Avatar
 
Join Date: Mar 2002
Location: Austin, TX
Posts: 516
Default

Great post. I think my AIR pump motor might be crapping out. I may just remove the whole thing.
General Jack is offline  
Old 05-30-2005, 01:13 PM
  #7  
11 Second Club
iTrader: (19)
 
99Hawk262's Avatar
 
Join Date: Jan 2005
Location: Little Rock
Posts: 2,491
Default

That's odd......I removed my A.I.R. system on my '99 and it didn't look anything like that. My air pump was bigger and rounder, and I didn't have all that stuff behind the intake manifold. The two hoses that ran down to the manifolds were connected into one hose that ran along the driver side fender well and down to the pump. I pulled it all out and there was nothing to cap off. My car picked up 3 MPG with the header install and it runs great, so I doubt I have any vacuum leaks. Is this normal for a '99 car?
99Hawk262 is offline  
Old 05-30-2005, 01:18 PM
  #8  
Teching In
Thread Starter
 
Join Date: Oct 2002
Location: San Antonio, TX
Posts: 22
Default

Hmmmm, maybe they changed the system to what I had. Anyone has any info on this? A change could also explain why the article I linked in my first post is so incomplete......at least to those who have the same system I had.
Most likely a change!!
Last_Z is offline  
Old 06-30-2005, 10:09 AM
  #9  
TECH Fanatic
 
Join Date: Mar 2003
Location: La Porte, TX
Posts: 1,839
Default

Yes the AIR system was changed in 00' But your writeup is still pretty good. Anyone with a 98-99 should still be able to follow your directions. The only differences are as listed above.
WS6snake-eater is offline  
Old 06-30-2005, 11:38 AM
  #10  
Staging Lane
 
neonblack's Avatar
 
Join Date: Feb 2005
Location: Chicago
Posts: 82
Default

Pardon my ignorance, but what exactly does the AIR system do? Is it beneficial to remove it, performance wise?

Thanks
neonblack is offline  
Old 06-30-2005, 02:21 PM
  #11  
TECH Addict
iTrader: (2)
 
slowpoke96z28's Avatar
 
Join Date: May 2005
Location: cedar hill, tx
Posts: 2,065
Default

it is designed to provide fesh air for the catalytic converter to use to catalyze the hydrocarbons that didn't get burned in the chamber. if you don't have cats any more, its just extra weight.
slowpoke96z28 is offline  
Old 06-30-2005, 04:22 PM
  #12  
TECH Regular
iTrader: (2)
 
USMARINE1108's Avatar
 
Join Date: Apr 2005
Location: Beaufort SC
Posts: 461
Default

that's a outstanding write up!
USMARINE1108 is offline  
Old 07-01-2005, 07:12 PM
  #13  
TECH Resident
 
Tranzaman00's Avatar
 
Join Date: Jul 2004
Location: It's hard work to look this good
Posts: 813
Default

this is great, you don't know how much I appreciate this. I have been dealing with this backfire problem for over 2 years, I just had a dyno tune using ls1 edit and stii could not figure out the problem. After reading this I took out the air pump and all backfires gone plus the car runs better. Thanks a bunch.
Tranzaman00 is offline  
Old 07-02-2005, 05:32 PM
  #14  
gwj
TECH Addict
 
Join Date: Nov 2001
Location: Live Oak, FL - in the woods where the creatures lurk.
Posts: 2,003
Default

Very well done! I evidently missed this when it was posted. I was going to do this about 100K miles back, LOL.
gwj is offline  
Old 07-02-2005, 07:41 PM
  #15  
TECH Fanatic
iTrader: (4)
 
JBIRD02's Avatar
 
Join Date: Jul 2003
Location: Orange Park/ Jacksonville, FL
Posts: 1,075
Default

great write up!!! now if I may...how the hell did you get that 15mm bolt off the back of the driver's side cyl head??!!! I can get a wrench on it, but cant turn it, any tips/tricks would be greatly appreciated. So far all I have done is remove the check valves and made my own block off plates. Thanks!
JBIRD02 is offline  
Old 07-02-2005, 09:18 PM
  #16  
TECH Addict
iTrader: (49)
 
HavATampa's Avatar
 
Join Date: Aug 2003
Location: Louisiana
Posts: 2,128
Default

Very good write up Rick. I have a 2000 and also removed the AIR a few years ago using the link you posted. Supposedly this model year had the extra crap that the other models didn't have and can be confusing. Thanks for clearing it up! Anybody know the official name for this part that mounts by the coils? I never removed it. Just plugged the line.

HavATampa is offline  
Old 07-02-2005, 09:38 PM
  #17  
TECH Fanatic
iTrader: (17)
 
jimmypop13's Avatar
 
Join Date: Nov 2001
Location: SPRING, TX
Posts: 1,387
Default

I wonder how long it takes for the check valves to die. I've had my car almost 4 years, 43,000 miles and most with headers and AIR restrictor plates(make the hole smaller, dont totally block off) and havn't had any problems yet.
jimmypop13 is offline  
Old 07-03-2005, 01:30 AM
  #18  
TECH Senior Member
iTrader: (6)
 
WILWAXU's Avatar
 
Join Date: Nov 2001
Location: San Diego, CA
Posts: 14,378
Default

Good job!

Great pic's!
WILWAXU is offline  
Old 07-03-2005, 11:34 PM
  #19  
TECH Fanatic
iTrader: (7)
 
Zymosis's Avatar
 
Join Date: Jan 2005
Location: Lincoln, NE
Posts: 1,309
Default

That was a great post man, I was going to do that this week, now it makes life 100x easier.
Zymosis is offline  
Old 07-04-2005, 12:18 AM
  #20  
jrp
SN95 Director
iTrader: (16)
 
jrp's Avatar
 
Join Date: Jul 2003
Location: Valencia, Ca
Posts: 10,754
Default

good stuff, added to the exhaust guide
jrp is offline  

Thread Tools
Search this Thread
Quick Reply: Exhaust backfires, running rich, poor mileage....come in! (AIR removal)


About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: