1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

extremly rough idle with smooth acc

Thread Tools
 
Search this Thread
 
Old Oct 25, 2007 | 07:19 PM
  #1  
thafox's Avatar
Thread Starter
nother rican witha rotary
Tenured Member 10 Years
 
Joined: Mar 2002
Posts: 1,034
Likes: 0
From: S.Otown
Exclamation extremly rough idle with smooth acc

ok,i looked on the -se idle problem site and found something similar but not exactly like my problem, i was just driving home from work 2day and as i came to a stop it felt like the whole car was shaking and it was idling round 700-800 i tap the throttle a bit to take it up 100rpm and it's smooth, still have all the power and everything, it's just a very rough idle and idk where to look first, tune up was done not to long ago, has about 200520miles (i know i know everyones' gonna say time 4 a rebuild, but that's not exactly what i'd like to hear right about now lol lacking in the funds dept right about now and this is my daily) i dont really do much other than drive it normaly everyday shift round 3k and this happened when i was just driving listening to the radio like normal, no ac on or anything else just the radio
Reply
Old Oct 25, 2007 | 07:25 PM
  #2  
Rx-7Doctor's Avatar
Lives on the Forum
Tenured Member 10 Years
iTrader: (13)
 
Joined: Jul 2004
Posts: 10,584
Likes: 12
From: Oregon
Has the sound of the engine changed at all?
Any loss of power?
Reply
Old Oct 25, 2007 | 07:29 PM
  #3  
thafox's Avatar
Thread Starter
nother rican witha rotary
Tenured Member 10 Years
 
Joined: Mar 2002
Posts: 1,034
Likes: 0
From: S.Otown
Originally Posted by rx7doctor
Has the sound of the engine changed at all?
Any loss of power?
no loss of power...yes diff sound of the engine just when it's idling rough but when i tap the throttle a bit it sounds normal
Reply
Old Oct 25, 2007 | 07:52 PM
  #4  
Rx-7Doctor's Avatar
Lives on the Forum
Tenured Member 10 Years
iTrader: (13)
 
Joined: Jul 2004
Posts: 10,584
Likes: 12
From: Oregon
Perform a compression test.

Could be vacuum leak, check all hoses and the air intake hose connections especially where the 2 pieces of the hose join together.
Reply
Old Oct 26, 2007 | 06:36 AM
  #5  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Yeah, time for a compression check. Driving casually all the time like that, you might have built up enough carbon to cause an apex seal to stick. A can of Seafoam through a partial (1/8 - 1/4) tank of gas could correct that, if that is the issue...
Reply
Old Oct 26, 2007 | 07:21 AM
  #6  
85 FB's Avatar
7-less
Tenured Member 05 Years
 
Joined: Dec 2005
Posts: 2,053
Likes: 0
From: No. Virginia, USA
What about steaming the engine with a spray bottle full of water through the vacuum hose of the brake booster? Would that also work?
Reply
Old Oct 26, 2007 | 12:01 PM
  #7  
bliffle's Avatar
Rotary Freak
Tenured Member 10 Years
 
Joined: Sep 2002
Posts: 2,815
Likes: 0
From: SF BayArea
I've found that all my rotarys run smoother once I start adding 6-8oz. of MMO to every fillup of gas. Better than the radical de-carb treatments.
Reply
Old Oct 26, 2007 | 12:35 PM
  #8  
thafox's Avatar
Thread Starter
nother rican witha rotary
Tenured Member 10 Years
 
Joined: Mar 2002
Posts: 1,034
Likes: 0
From: S.Otown
Ok wtf....its not doin it anymore since this morning....I started it up 1st time this morning and it was back 2 normal ever since....and I've been driving pretty much all day
Reply
Old Oct 26, 2007 | 12:37 PM
  #9  
85 FB's Avatar
7-less
Tenured Member 05 Years
 
Joined: Dec 2005
Posts: 2,053
Likes: 0
From: No. Virginia, USA
Any change in weather in your area? My car is a bit finicky when it gets really cold sometimes.
Reply
Old Oct 26, 2007 | 06:44 PM
  #10  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,833
Likes: 3,232
From: https://www2.mazda.com/en/100th/
Originally Posted by thafox
Ok wtf....its not doin it anymore since this morning....I started it up 1st time this morning and it was back 2 normal ever since....and I've been driving pretty much all day
sticking bac valve maybe, or a vacuum leak. the big air duct hoses, since one end is on the car and the others on the motor, can leak intermittantly
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
HalifaxFD
Canadian Forum
126
May 9, 2016 07:06 PM
The1Sun
New Member RX-7 Technical
5
Sep 15, 2015 04:45 PM
firzen
2nd Generation Specific (1986-1992)
9
Sep 15, 2015 12:04 PM
RotaryBobby
1st Generation Specific (1979-1985)
1
Sep 10, 2015 01:33 PM
The1Sun
1st Generation Specific (1979-1985)
0
Sep 7, 2015 10:21 PM




All times are GMT -5. The time now is 05:26 PM.