2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Backfire question

Thread Tools
 
Search this Thread
 
Old 05-19-06, 09:57 AM
  #1  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
Backfire question

I know this has always been a question here but someone told me yesterday that it was bad, well my car backfires in every gear after around 5.5k when I let it go or shift. Its a 90 gtu with no cat (Im pretty shure theres my problem).
Old 05-19-06, 10:02 AM
  #2  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
Ohh and I knew I had another question, its Idleing like crap too, it idles at 300 and it goes up and down all the time.
Old 05-19-06, 10:08 AM
  #3  
King of the Loop

 
BklynRX7's Avatar
 
Join Date: Apr 2004
Location: brooklyn, New York
Posts: 2,620
Likes: 0
Received 1 Like on 1 Post
Arrow

Who told you it was a problem?? Someone who doesnt know anything about rotaries?
Old 05-19-06, 10:19 AM
  #4  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
the guy drives an fb but I dont think he knows alot, my dad told me it was cool but sometimes I dont trust my dad too much cause he only works on fd's, but I guess is ok then right?
Old 05-19-06, 10:20 AM
  #5  
Senior Member

 
synesthete's Avatar
 
Join Date: Aug 2005
Location: Portland. OR
Posts: 303
Likes: 0
Received 0 Likes on 0 Posts
It's pretty normal for a little afterburn on aftermarket exhaust. I have a bonez cat and mine will do it when i get above 6k or so. The guys with no cat and headers, and fart can mufflers will actually pop flames, and apparently they dont mind this.

The idle problem may be that its just set to low. 750 is the normal idle speed, so if yours is around 300 you need to raise it up.
Old 05-19-06, 10:22 AM
  #6  
He who smokes bitches

 
cool_as_crap's Avatar
 
Join Date: Jun 2005
Location: El Dorado County
Posts: 3,452
Received 0 Likes on 0 Posts
5.5k sounds kinda low actually. i have no cat and i dont backfire unless i take it up to 7.5
Old 05-19-06, 10:25 AM
  #7  
Rotaries confuse me

iTrader: (7)
 
My5ABaby's Avatar
 
Join Date: May 2006
Location: Murfreesboro, TN
Posts: 4,219
Likes: 0
Received 3 Likes on 3 Posts
How hot does the exhaust have to be for it to shoot flames? As in, will it only work after/during hard driving?
Old 05-19-06, 10:28 AM
  #8  
ALLyourRX7areBELONGtoUS

 
1987_Gxl's Avatar
 
Join Date: Apr 2004
Location: Shoreline,WA
Posts: 357
Likes: 0
Received 0 Likes on 0 Posts
my pops if i redline in first.... wondering if my cats have been gutted or not.
I'm fairly certain that my 13b may also have a streetport of some kind, and is a rebuild

Last edited by 1987_Gxl; 05-19-06 at 10:31 AM.
Old 05-19-06, 10:30 AM
  #9  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
yeah I have an hks ex. and no cat, so thats cool, yeah my dad told me about actually adjusting my idle too (sorry I ask u guys before doing anything even if I know), Is that Ive just been with rotarys for like a year 1/2, my dad's been with them forever but then again he's blown a bunch of engines so I guess thats why I havent trusted him alot with my car cause Ive seen those engines blow since I was little (sorry for telling u my life). well thanks
Old 05-19-06, 10:32 AM
  #10  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
ohh and yeah it actually does it at around 6k I went out and checked.
Old 05-19-06, 10:39 AM
  #11  
rotorhead

iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 16,182
Received 429 Likes on 263 Posts
is your A/C on or off when it's idling like this?
Old 05-19-06, 10:41 AM
  #12  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
I dont even have it connected, it does go down when I move the stearing wheel (power stearing) and when I hit the break.
Old 05-19-06, 10:53 AM
  #13  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
Originally Posted by RxRolla
I know this has always been a question here but someone told me yesterday that it was bad, well my car backfires in every gear after around 5.5k when I let it go or shift. Its a 90 gtu with no cat (Im pretty shure theres my problem).
That's normal. The car runs momemtarily rich when the throttle snaps shut before the ECU catches up. It becomes more apparent with an open exhaust and if the car is out of tune.

Ohh and I knew I had another question, its Idleing like crap too, it idles at 300 and it goes up and down all the time.
That's a problem. Most likely a bad or dirty BAC valve, vacuum leak, or a combination of the two.
Old 05-19-06, 10:57 AM
  #14  
Rotary Enthusiast

 
jono20's Avatar
 
Join Date: May 2005
Location: Vernon, BC
Posts: 1,135
Likes: 0
Received 0 Likes on 0 Posts
I have no emmissions anything, header, straight resonator and straight single 3" exhaust. I pop as low as 3500 some times and I can blow flames at 5500
Old 05-19-06, 10:58 AM
  #15  
Full Member

Thread Starter
iTrader: (1)
 
RxRolla's Avatar
 
Join Date: Apr 2006
Location: San Antonio
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
thanks Ill check
Old 05-19-06, 11:24 AM
  #16  
King of the Loop

 
BklynRX7's Avatar
 
Join Date: Apr 2004
Location: brooklyn, New York
Posts: 2,620
Likes: 0
Received 1 Like on 1 Post
Arrow

Originally Posted by synesthete
The guys with no cat and headers, and fart can mufflers will actually pop flames, and apparently they dont mind this.

.
Not only do i not mind it, I actually enjoy it quite a bit. hmmmmmmm pop, hmmmmmmmmmmm pop POP pop POP
Old 05-19-06, 11:37 AM
  #17  
ALLyourRX7areBELONGtoUS

 
1987_Gxl's Avatar
 
Join Date: Apr 2004
Location: Shoreline,WA
Posts: 357
Likes: 0
Received 0 Likes on 0 Posts
it scares people on the sidewalk LOL
Old 06-23-06, 11:06 PM
  #18  
FD pro licensed driver

iTrader: (3)
 
TweakGames's Avatar
 
Join Date: Feb 2006
Location: Renton/Bellevue/Seattle WA
Posts: 2,897
Likes: 0
Received 2 Likes on 2 Posts
Hello. I just connected my air pump and my car pops every time I shift at somewhat high RPM, is the only way to get rid of this pop to disconnect the air pump again? I dont like the pop at all, to me it sounds like the car is broken. I like a nice smooth ride myself.
Old 06-23-06, 11:18 PM
  #19  
Now With 10th AE Fun!

iTrader: (1)
 
1SWEET7's Avatar
 
Join Date: Jun 2005
Location: CA
Posts: 1,869
Likes: 0
Received 0 Likes on 0 Posts
Oh the backfire is great you gotta love spitting a flame out the back. I don't really get it anymore with my new exhaust that only collects right before the muffler. I did get a really loud one the other night though. I used to be able to spit pretty good flames out the rear with a cat replacement pipe and stock exhaust.

EDIT: Here is a vid. http://videos.streetfire.net/search/...01F7A72C90.htm

Last edited by 1SWEET7; 06-23-06 at 11:30 PM.
Old 06-23-06, 11:21 PM
  #20  
tom port.. AKA streetport

iTrader: (6)
 
88rxn/a's Avatar
 
Join Date: Jan 2005
Location: ludlow, pa
Posts: 4,659
Likes: 0
Received 0 Likes on 0 Posts
bbrrraaaAAAAAAAA POP..
you doesnt like it!!
Old 06-24-06, 12:32 AM
  #21  
FD pro licensed driver

iTrader: (3)
 
TweakGames's Avatar
 
Join Date: Feb 2006
Location: Renton/Bellevue/Seattle WA
Posts: 2,897
Likes: 0
Received 2 Likes on 2 Posts
no I think it sounds VERY VERY cheap. If someone knows how I Can fix the poping let me know. I really dont want to have to take off the air pump, it really mellows out my exaust. (instead of so ricey) and seemed to have fixed my idle issue.
Old 06-24-06, 01:51 AM
  #22  
There were no survivors

 
EJayCe996's Avatar
 
Join Date: Aug 2004
Location: Grand Prairie, Texas
Posts: 2,475
Likes: 0
Received 1 Like on 1 Post
Originally Posted by Aaron Cake
That's normal. The car runs momemtarily rich when the throttle snaps shut before the ECU catches up. It becomes more apparent with an open exhaust and if the car is out of tune.
I think you missed this part that Aaron mentioned, TweakGames. While you're on a stock ECU with no piggyback, there is almost no way around a rotary backfiring, it is the partial nature of the beast. Stock ecu maps are RICH. If you don't have a cat then you shouldn't have the airpump on anyway. You're just feeding oxygen to fire, in a manner of speaking, at that point. If you still have a cat, then you need the airpump else you'll just end up destroying it. My car used to pop pretty good when all of the stock equipment was still attached. I had found out, when I moved up to a header and high flow cat, that my precat had blown out and into my main cat. My main cat had a nice circular chunk of its innards partially displaced. So if you still have the stock cat, I would suggest you inspect your cat to make sure it is not damaged like mine was. With my high flow, my backfires are no longer pops, usually, but just a subdued gurgling.
Old 06-24-06, 10:28 AM
  #23  
tom port.. AKA streetport

iTrader: (6)
 
88rxn/a's Avatar
 
Join Date: Jan 2005
Location: ludlow, pa
Posts: 4,659
Likes: 0
Received 0 Likes on 0 Posts
I REPEAT!!! HOW COULD YOU NOT LIKE THIS!!

for the record...this is not my picture!
Old 06-24-06, 01:42 PM
  #24  
yes,thats me \/

iTrader: (1)
 
cdaleracer669's Avatar
 
Join Date: Mar 2006
Location: Eaton, CO
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
i have been able to tune out alot of the popping with adjusting the TPS and the screw by the AFM by turning it to leaner. a misadjusted TPS will make it pop alot more than necessary, and that screw by the AFM seems to have alot to do with it also (on my car at least). mine still shoots flames at high RPM's tho
Old 06-24-06, 02:04 PM
  #25  
Junior Member

 
spoolin7's Avatar
 
Join Date: Aug 2004
Location: Oakland,Ca
Posts: 25
Likes: 0
Received 0 Likes on 0 Posts
every since i installed the rebuild I can't seem to shoot flames the way I use to

I'm still on a stock ecu with no obvious sound of back fire.


Quick Reply: Backfire question



All times are GMT -5. The time now is 11:07 AM.