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

Need Help: Rough Idling, Hard Acceleration & Car Shaking Like Hell

Thread Tools
 
Search this Thread
 
Old 03-25-10, 03:24 AM
  #1  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Need Help: Rough Idling, Hard Acceleration & Car Shaking Like Hell

Done :
  1. ghetto compression test
  2. ignition coil
  3. igniter
  4. vacuum/hose leak
  5. fuel pump

could it be :
  1. AVC & PCV problem?
  2. water leaks to housing?
  3. carb problem?

it's 1982 S2, 12A
will post the video later
Old 03-25-10, 04:01 AM
  #2  
backyard tuner

iTrader: (1)
 
Paradox's Avatar
 
Join Date: Sep 2002
Location: BC, Canada
Posts: 1,265
Likes: 0
Received 0 Likes on 0 Posts
did you do the fuel filter too?
Old 03-25-10, 07:51 AM
  #3  
Have RX-7, will restore


iTrader: (91)
 
mazdaverx713b's Avatar
 
Join Date: Oct 2003
Location: Ohio
Posts: 21,710
Received 1,051 Likes on 891 Posts
fuel filter is a prime suspect. also inspect the plugs for wear and corrosion. check the resistance of each plug wire and ensure they aren't arching. if what we've both mentioned is checked properly, including compression, its time for a carb rebuild.
Old 03-25-10, 11:22 AM
  #4  
1st-Class Engine Janitor

iTrader: (15)
 
DivinDriver's Avatar
 
Join Date: Jun 2008
Location: Chino Hills, CA
Posts: 8,376
Received 26 Likes on 24 Posts
Check dizzy cap and rotor condition, too.
Old 03-25-10, 12:17 PM
  #5  
Dreamin of drivin my 7!
iTrader: (18)
 
installer67's Avatar
 
Join Date: Feb 2009
Location: Seabeck, Washington
Posts: 1,073
Likes: 0
Received 1 Like on 1 Post
Possibly bad fuel as well, water etc. in tank.
Old 03-25-10, 04:54 PM
  #6  
Old Fart Young at Heart

iTrader: (6)
 
trochoid's Avatar
 
Join Date: Apr 2004
Location: St Joe MO
Posts: 15,145
Likes: 0
Received 7 Likes on 7 Posts
What was the result of the ghetto compression test? While the engine is idling, pull 1 plug wire off at a time and note any changes in idle. If you find 1 wire that doesn't change the idle, inspect all of that part of the ignition system from the plug back to the dizzy rotor.
Old 03-25-10, 09:03 PM
  #7  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by DivinDriver
Check dizzy cap and rotor condition, too.
Both replaced with new one. Any chance the pickup coil got problem? when i crank there are sparks at both T & L plugs, but i'm not sure if it is adequate enough to burn the fuel.
Old 03-25-10, 09:11 PM
  #8  
Junior Member
 
Zackqw's Avatar
 
Join Date: Mar 2010
Location: Washington
Posts: 46
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 2kilo2
Both replaced with new one. Any chance the pickup coil got problem? when i crank there are sparks at both T & L plugs, but i'm not sure if it is adequate enough to burn the fuel.
actually i just had the same problem with my car.. 79 (not sure what kind) 13B.. it had REALLY bad gas in it.. check ur spark plugs if they are falled then replace them and get a can or 2 of this stuff called SeaFoam.. works greak.. add about 6 gal of gas... should burn pretty well.. if it still idls funny.. replace the fuel filter...(might be 2 on ur car there is on mine) thats my suggestion
Old 03-25-10, 11:46 PM
  #9  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by trochoid
What was the result of the ghetto compression test? While the engine is idling, pull 1 plug wire off at a time and note any changes in idle. If you find 1 wire that doesn't change the idle, inspect all of that part of the ignition system from the plug back to the dizzy rotor.
I got strong pulses from both rotors. I remember last week i've done that but forgot to note which plugs changes the idle when unplugged.

Originally Posted by Zackqw
actually i just had the same problem with my car.. 79 (not sure what kind) 13B.. it had REALLY bad gas in it.. check ur spark plugs if they are falled then replace them and get a can or 2 of this stuff called SeaFoam.. works greak.. add about 6 gal of gas... should burn pretty well.. if it still idls funny.. replace the fuel filter...(might be 2 on ur car there is on mine) thats my suggestion
Spark plugs seems fine, but not sure it had correct timings. i believe Seafoam only sold in US & Canada, not in my country (asia region), the best i have is MMO, i don't know if it is a substitute for seafoam. have stock it a lot since i realized that the MOP malfunction (few mths after i bought it from ex-owner + some searches in the forum).

Originally Posted by installer67
Possibly bad fuel as well, water etc. in tank.
Might be. I remember in the early 80's we only have RON87 & RON91 for our cars here. not sure which fuel is better as i stick with RON87 fuel.

Last year the radiator fins corroded & gone bad, i send it to the radiator shop to recore with new 3 row type. My mistake is i don't replace the water pump that time (coz of tight budget). Everytime i run 140km/h+ the engine temp starting to rise from normal temp to 110-130 degree celsius. Well engine overheat is bad for rotaries, but hopefully this is not in my case.

Last edited by mar3; 03-26-10 at 01:02 AM. Reason: Merged back-to-back posts...
Old 03-26-10, 12:10 AM
  #10  
My 7 is my girlfriend.

iTrader: (5)
 
orion84gsl's Avatar
 
Join Date: Feb 2006
Location: London, Ontario, Canada
Posts: 3,162
Likes: 0
Received 1 Like on 1 Post
Check your fuel filter first and foremost. It's a cheap and easy fix if it's the problem and just good maintenance even if it isn't the problem. The stock filters can clog up quickly and your symptoms sound like a clogged filter.
Old 03-26-10, 12:11 AM
  #11  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Sorry guys for my bad english. I'm not that good in english. Hopefully you all understand the words i type here.

Originally Posted by orion84gsl
Check your fuel filter first and foremost. It's a cheap and easy fix if it's the problem and just good maintenance even if it isn't the problem. The stock filters can clog up quickly and your symptoms sound like a clogged filter.
Will do it ASAP. FYI, every time i filled in the gas i always mixed it with MMO or 2 stroke oil in the tank. I hope those MMO/2T oil is the reason the fuel filter clog up. I got no other way to run premix except by filling it in the tank.

Last edited by mar3; 03-26-10 at 01:02 AM. Reason: Merged back-to-back posts...
Old 03-26-10, 06:02 AM
  #12  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Just replaced the fuel filter, still no improvement. it must be something else.
Old 03-26-10, 10:39 AM
  #13  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
today i got chance to drive the car, max speed 100km @around 2500rpm for about 70km destination, water temp rise to 110 degree celsius which is not normal, coolant reservoir drying up (i filled up the radiator & reservoir before i drive).

possibility :

worn out water pump & inadequate air sucks to the intake which leads to carburetor Air/Fuel mixture problem (time to rebuild)?
Old 03-26-10, 10:19 PM
  #14  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
bump anyone?
Old 03-28-10, 11:18 PM
  #15  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
http://www.facebook.com/video/video.php?v=1258211581534
Old 03-29-10, 01:35 AM
  #16  
Junior Member
Thread Starter
 
2kilo2's Avatar
 
Join Date: Jun 2008
Location: Brunei
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
nevermind, the rear rotor lost compression today. thanks for the help & suggestions.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bb6guy
Old School and Other Rotary
10
10-01-18 08:07 AM
alphawolff
1st Generation Specific (1979-1985)
17
11-17-15 05:57 PM
rotor_veux
2nd Generation Specific (1986-1992)
10
08-23-15 09:06 PM
bb6guy
3rd Generation Specific (1993-2002)
3
08-12-15 03:29 PM



Quick Reply: Need Help: Rough Idling, Hard Acceleration & Car Shaking Like Hell



All times are GMT -5. The time now is 07:59 AM.