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

She's Moaning but never gets to peak

Thread Tools
 
Search this Thread
 
Old Apr 10, 2008 | 11:44 AM
  #1  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
She's Moaning but never gets to peak

I've got an 88' vert, N/A. Recently I noticed that under load ( hills) a throaty moan was developing under the hood. Overall did'nt appear to be a problem , was kind of sexy. Then a bit later I noticed a loss of power under load. Time marched on & now the loss of power is extreme, I can barely get it up my driveway. Step on the gas & she will howl up to 4 grand & then start to choke & approach a stall. She idles O.K. & seems to be ok up to 2K revs, after that she moans. My training says look for the simplest or most recently changed.

* I've checked the plugs, seem to be ok slightly carbonized but nothing unusual. Cleaned them up & reinstalled.
* Removed the K&N air filter, fired it up-no change except louder howling!
o Suspecting I may have lost an injector, I checked the plug connectors. Seem to be functional & connected.


My guess is that it's a fuel delivery or massive vacumn leak problem. I can't locate any blown hoses or whistle noises. What's your take on what to check next.
Reply
Old Apr 10, 2008 | 11:47 AM
  #2  
Delicious's Avatar
Banned. I got OWNED!!!
 
Joined: Oct 2007
Posts: 420
Likes: 0
From: Manteca, CA
check your apex seals, ha
Reply
Old Apr 10, 2008 | 11:57 AM
  #3  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
Hey, c'mon, I already took one zanex this a.m. & now you've got me feeling all depressed again. This is one of ATKIN"S finest rebuilds only 35K on this puppy. Tell me it aint so.
Reply
Old Apr 10, 2008 | 12:14 PM
  #4  
Mankdrake 2661's Avatar
Mazda goes MMMMMMMM
Tenured Member: 20 Years
iTrader: (8)
 
Joined: Oct 2004
Posts: 1,002
Likes: 1
From: Collinsville, IL
clogged cat...........

If it was a vacuum leak it would idle funny if at all.
Reply
Old Apr 10, 2008 | 12:41 PM
  #5  
Rotorious7's Avatar
Senior Member
Tenured Member 20 Years
iTrader: (1)
 
Joined: Dec 2001
Posts: 488
Likes: 0
From: Atlanta, GA
sounds like my ex wife
Reply
Old Apr 10, 2008 | 01:02 PM
  #6  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
clogged cat? that might explain why it came on gradually. Is there a fast & dirty way to check. All of the exhaust is new, with the exception of the cat. If I can gauge by the intake air she seems to be breathing fine. I was leaning towards a fuel delivery problem. Enough to idle & feed the engine to 2K but not enough when you ask for power under load...
Reply
Old Apr 10, 2008 | 01:30 PM
  #7  
TehMonkay's Avatar
Back in the game
Tenured Member 10 Years
iTrader: (-1)
 
Joined: Nov 2005
Posts: 2,456
Likes: 2
From: Louisville KY
Does it have the stock main and primary cats? If so, I suggest getting those replaced ASAP, I think most of them are done by 130K. You only need one though, if you have a header get a 2.5" cat instead of the stock size though, otherwise just get a new pipe from the manifold to a replacement cat with an air injection port.

Shouldnt cost too much if you order the cat online yourself.
Reply
Old Apr 10, 2008 | 01:53 PM
  #8  
Mankdrake 2661's Avatar
Mazda goes MMMMMMMM
Tenured Member: 20 Years
iTrader: (8)
 
Joined: Oct 2004
Posts: 1,002
Likes: 1
From: Collinsville, IL
Originally Posted by RXinator
clogged cat? that might explain why it came on gradually. Is there a fast & dirty way to check. All of the exhaust is new, with the exception of the cat. If I can gauge by the intake air she seems to be breathing fine. I was leaning towards a fuel delivery problem. Enough to idle & feed the engine to 2K but not enough when you ask for power under load...
Unbolt the cat, get your ear plugs and go for a drive! Or just look down the inlet of the first cat and see what's there.
Reply
Old Apr 10, 2008 | 09:04 PM
  #9  
Dr-Zine's Avatar
Full Member
Tenured Member 10 Years
iTrader: (1)
 
Joined: Jul 2004
Posts: 89
Likes: 1
From: Minneapolis
Check your tps. Similar thing is happening to me right now, but not as extreme. In my case, the tps wont hold the correct adjustment (the 2 LED thingy). I can set it to spec then go for a drive. She will pull normaly full power for a few moments, then go out of adjustment and bog out and nearly stall.

It might be worth a shot checking that out.
Reply
Old Apr 10, 2008 | 10:29 PM
  #10  
Project88Turbo's Avatar
Stock boost FTW!
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (22)
 
Joined: Nov 2004
Posts: 1,139
Likes: 114
From: Berlin, MD
My first RX-7 started making a really sweet sound like the one you described when I had just got it. I couldn't drive it on the street so I started it every so often and revved it up. My friend and I were saying "This thing sounds AWESOME!!" About 2 minutes later, the exhaust behind the main converter just FELL off and it became incredibly loud...

Vince
Reply
Old Apr 10, 2008 | 10:37 PM
  #11  
greenscar66's Avatar
Junior Member
 
Joined: Apr 2008
Posts: 11
Likes: 0
From: Cambridge, OH
clogged catalytic and/or problems with secondaries.
Reply
Old Jun 1, 2008 | 07:52 PM
  #12  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
I recently quiered the forum " she's moanin". Loss of power eventually led to no start at all. Adjusted the Throttle position, no go, then I dropped the cats and bingo shes up & running. My question is what do I look for to determine that the cat has clogged. I got the rear cat down today & it looks fine, nice grid of material, lots of small holes no sign of it being plugged. I'll get the primary down next & take a look. If I decide to tunnel it out should I do both, primary & secondary? If the primary is toast, should I just do that one. I've been told that the engines won't perform properly without back pressure of the cats on line, is that true? Whats the best tool to use to perform the deed of coring out the cats? .......lee
Reply
Old Jun 1, 2008 | 10:53 PM
  #13  
SpikeDerailed's Avatar
This sh*t burns oil!
Tenured Member: 15 Years
iTrader: (7)
 
Joined: Oct 2006
Posts: 1,239
Likes: 5
From: Charlotte, NC - USA
Originally Posted by RXinator
I recently quiered the forum " she's moanin". Loss of power eventually led to no start at all. Adjusted the Throttle position, no go, then I dropped the cats and bingo shes up & running. My question is what do I look for to determine that the cat has clogged. I got the rear cat down today & it looks fine, nice grid of material, lots of small holes no sign of it being plugged. I'll get the primary down next & take a look. If I decide to tunnel it out should I do both, primary & secondary? If the primary is toast, should I just do that one. I've been told that the engines won't perform properly without back pressure of the cats on line, is that true? Whats the best tool to use to perform the deed of coring out the cats? .......lee
My engine performs fine without any cats, although a little less low rpm power(in exchange for a little more top end). On my other cars I used a big *** pry bar to break through the material.
Reply
Old Jun 1, 2008 | 11:12 PM
  #14  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
Done, done, & done for now Cleared the cats front two looked clogged, the third looked pretty clear. Bolted her up and same crap. So off comes the 3rd cat , tunneled it out & we're sailing. Alls back to normal with the exception of a backfire coming off 1st & 2ond. That I'll live with for a while. Anyone got an answer as to weather the rotary is designed for the backpressure of the cats. Maybe that would esplain the backfiring.
THANK YOU ALL FOR THE HELP & SUPPORT, SPREAD THE LOVE
Reply
Old Jun 1, 2008 | 11:26 PM
  #15  
onehalfasia's Avatar
Full Member
Tenured Member 05 Years
iTrader: (5)
 
Joined: May 2006
Posts: 196
Likes: 0
From: spokane
i think you need a new battery...son
Reply
Old Jun 2, 2008 | 01:16 AM
  #16  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
Can't say I get your drift, pardner
Reply
Old Jun 2, 2008 | 10:53 AM
  #17  
SpikeDerailed's Avatar
This sh*t burns oil!
Tenured Member: 15 Years
iTrader: (7)
 
Joined: Oct 2006
Posts: 1,239
Likes: 5
From: Charlotte, NC - USA
Originally Posted by RXinator
I recently quiered the forum " she's moanin". Loss of power eventually led to no start at all. Adjusted the Throttle position, no go, then I dropped the cats and bingo shes up & running. My question is what do I look for to determine that the cat has clogged. I got the rear cat down today & it looks fine, nice grid of material, lots of small holes no sign of it being plugged. I'll get the primary down next & take a look. If I decide to tunnel it out should I do both, primary & secondary? If the primary is toast, should I just do that one. I've been told that the engines won't perform properly without back pressure of the cats on line, is that true? Whats the best tool to use to perform the deed of coring out the cats? .......lee
My engine performs fine without any cats, although a little less low rpm power(in exchange for a little more top end). On my other cars I used a big *** pry bar to break through the material.
Reply
Old Jun 2, 2008 | 02:35 PM
  #18  
SaabGuy's Avatar
Rotary Freak
Tenured Member: 20 Years
 
Joined: Oct 2001
Posts: 1,515
Likes: 1
From: Atlanta, GA
FYI, I had a similar circumstance of groaning and moaning from the clutch/fan after I upgraded the radiator. The fan shrowd was sooo close to the fan that it was rubbing bigtime. The replacment radiator was about an inch wider and consiquently the fan shrowd was closer to the fan.
Reply
Old Jun 2, 2008 | 10:54 PM
  #19  
RXinator's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 29
Likes: 0
From: Sebastopol CA
Well we beat this one up pretty good....problem solved for now, but anyone have suggestions for replacement cats. I don't like the way it growls now with all the cats bored out. I also miss the low end torque. I assume I only have to replace the one primary cat with the air inlet. Any expertise on exhaust replacement. All exhaust after the cats is new high flow duals. ........rxinator
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Shainiac
Single Turbo RX-7's
12
Jul 17, 2019 02:20 PM
24seven_dada
3rd Generation Specific (1993-2002)
20
Nov 10, 2018 12:03 PM
cto_2
Introduce yourself
19
May 8, 2018 08:15 AM
gxl90rx7
Haltech Forum
6
Jun 30, 2017 11:30 PM
ZacMan
Build Threads
4
Sep 19, 2015 09:20 PM




All times are GMT -5. The time now is 09:30 AM.