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

No compression in 1 rotor

Thread Tools
 
Search this Thread
 
Old Mar 1, 2005 | 10:44 AM
  #1  
UnknowingBuddha's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Apr 2004
Posts: 5
Likes: 0
From: St. Thomas, Ontario
Question No compression in 1 rotor

This car I bought sat for 8 months, and it starts, but has no power and shows zero compression on one rotor (the front one). I am assuming I need to have it rebuilt? Someone told me it would likely be one of the seals (apex or other) have dislodged.

Can anyone shed some light on this?

T.
Reply
Old Mar 1, 2005 | 10:50 AM
  #2  
fong's Avatar
Rotary Enthusiast
iTrader: (77)
 
Joined: Oct 2001
Posts: 1,197
Likes: 3
From: Maryland
you already got the correct information: no compression = rebuild

good luck with that
Reply
Old Mar 1, 2005 | 02:50 PM
  #3  
YearsOfDecay's Avatar
Locust of the apocalypse
Tenured Member 05 Years
 
Joined: Apr 2003
Posts: 2,553
Likes: 2
From: Directly above the center of the earth (York, PA)
what happenes is that as the motor sits without being started, the carbon deposits and oil sludge in the apex seal grooves can harden, thus freezing the apex seal and letting compression get by.
Reply
Old Mar 1, 2005 | 02:52 PM
  #4  
bcool's Avatar
Rest In Peace Dave
Tenured Member 15 Years
 
Joined: Feb 2004
Posts: 1,347
Likes: 1
From: Idaho
you'd figure it would free up if its been running.
Reply
Old Mar 1, 2005 | 03:00 PM
  #5  
fong's Avatar
Rotary Enthusiast
iTrader: (77)
 
Joined: Oct 2001
Posts: 1,197
Likes: 3
From: Maryland
Smile different case

Originally Posted by YearsOfDecay
what happenes is that as the motor sits without being started, the carbon deposits and oil sludge in the apex seal grooves can harden, thus freezing the apex seal and letting compression get by.
didn't you see in his note, he said that he started the car, but runs no power?

if car sits for long time, can use ATF to restore the compression. but after the car starts, runs, if still no power(compression), then rebuild is the only way to go, or sell the car.
Reply
Old Mar 1, 2005 | 11:03 PM
  #6  
UnknowingBuddha's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Apr 2004
Posts: 5
Likes: 0
From: St. Thomas, Ontario
I think it's a good call to at least *try* the ATF trick first. I'll Google it tonight and refresh my memory on what to do. Maybe when there's less than a foot of snow on the thing I'll be able to get near the engine!

Thanks guys, for your help.
Reply
Old Mar 1, 2005 | 11:28 PM
  #7  
Senior Member
Tenured Member 05 Years
 
Joined: Sep 2003
Posts: 355
Likes: 0
From: Berthier, Quebec
hummmmmmm guys... From what i've read since a year on this forum is that : YOUR ENGINE CANNOT RUN ON ONE ROTOR

and then, this guy arrives and it doesn't only runs, it starts!!!

so it's possible to have the car start with one rotor? :s
Reply
Old Mar 1, 2005 | 11:50 PM
  #8  
UnknowingBuddha's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Apr 2004
Posts: 5
Likes: 0
From: St. Thomas, Ontario
Yes - the car does run. It starts up, and although it won't idle, you can keep it running with your foot on the accelerator a bit. It sounds a bit like a broken lawnmower though!

I understand you need compression on both sides to run properly. Thanks for your reply.
Reply
Old Mar 2, 2005 | 12:20 AM
  #9  
ddub's Avatar
i am legendary
Tenured Member 05 Years
 
Joined: Sep 2003
Posts: 8,478
Likes: 1
From: Kirkland, WA
Originally Posted by TII '87
hummmmmmm guys... From what i've read since a year on this forum is that : YOUR ENGINE CANNOT RUN ON ONE ROTOR

and then, this guy arrives and it doesn't only runs, it starts!!!

so it's possible to have the car start with one rotor? :s
Yes it can "run" on one rotor. It will drive like ****, wont idle worth crap, and will have no power, but it can run.
Reply
Old Mar 2, 2005 | 01:05 AM
  #10  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
you can try various methods to try and pop the seals loose but it may or may not work, first i would try pumping a bit of 2 stroke oil(a tablespoon or so) into the leading plug hole on the #1 rotor and crank the engine for about 10 revolutions and let it sit for a few hours then fire it up, spray some top end cleaner into the front upper vacuum hose while trying to keep the engine running, this may or may not work. and the leading cause of sticking seals is rust, not easy to break free once it has set in...
Reply
Old Mar 2, 2005 | 03:10 AM
  #11  
topaz's Avatar
Greek Geek
Tenured Member 15 Years
 
Joined: Oct 2003
Posts: 264
Likes: 1
From: Greece - Athens [www.RX7.gr]
Remove spark from the "0" rotor. Inject mineral oil with a syringe. At the gazoline depozit, you might wanna add some octane booster product. Insert the plugs back at position.

Pray.

Try to start the motor regularly. If you are damn lucky, the added oil will make the carbon etc to get away from the stack apex seal. The motor will run a bit rough, and thats why you add octane booster product, just in case.
Of course if the trick works, you will have to change ASAP oil and you might wanna clean the chambers with other prosedures. (de-carbon with water)
Reply
Old Mar 2, 2005 | 04:05 AM
  #12  
5252's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Feb 2005
Posts: 137
Likes: 0
From: Sweet Home Alabama!!!
Pour about a shot or so in the spark plug hole and be sure you pull the fuses for the fuel, there is two. Pour a shot or so (maybe a tad less) in there and you can even go on and spin the engine (with a socket on the pully, dont do it with the key lol) and pour some on all three sides of the rotor. Let it set over night (for about 24 hours or so) then try to start it (WITH THE 2 FUEL FUSES OUT). You should do it at night, cause when you go to start it, there will be a HUUUUUUUUGGEEEEE cloud of smoke, like people will think your house in on fire lol. oh yeah, you need to have the spark plug and the spark plug wire back on the engine lol.

If that dont fee up the carbon ("carbon lock"), you will have to have it rebuilt, the kit is about $1000 and you might need new or at least some low mileage rotor housings, which is another $4-800.

GOOD LUCK WITH IT!!! I hope some of this is helpful for you.

Oh yeah--- When you do your compression test, be sure you listen for 3 pulses, cause there is three compression points on the rotor. It will be in a beat so to speak, if you know what I mean...

3 compression pulses, like--- [pf, pf, pf,] not [pf,,, pf, pf,] or [pf,,,,,, pf,,,,,, pf] or [pf, pf,,, pf,] LOL ha ha i dont know if that really helps any lol but if you can play any instruments and can read music, I think you will understand it lol.
Reply
Old Mar 2, 2005 | 05:40 AM
  #13  
SpAm@FC's Avatar
Senior Member
Tenured Member 15 Years
iTrader: (4)
 
Joined: Jun 2003
Posts: 734
Likes: 1
From: Austria
@5252

only 4 info...

if you crank your engine with a socket an without plugs you should here every half turn a "plop"...

on 3 full rotations you should hear 6 pops... if you only hear 4 pops you have blown 1 apex... if you hear 2 pops you have blowed one apex in the front and one in the rear housing! if you hear 3 pops you have killed at least 2 apex or all three apex in one housing
Reply
Old Mar 2, 2005 | 08:56 AM
  #14  
drft_180sx's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Feb 2004
Posts: 702
Likes: 0
From: NYC/Stony Brook Univ.
^^Sorry to thread jack....but what if you get 5 pops??? My car has been sitting around cause i thought i blew an apex seal...

FRONT_________REAR
..Pop
.............................Pop
..Pop
.............................Pop
..Pop
.............................Silence!!

Repeat cycle....

Last edited by drft_180sx; Mar 2, 2005 at 08:59 AM.
Reply
Old Mar 2, 2005 | 12:40 PM
  #15  
drft_180sx's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Feb 2004
Posts: 702
Likes: 0
From: NYC/Stony Brook Univ.
bump?
Reply
Old Mar 2, 2005 | 11:41 PM
  #16  
5252's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Feb 2005
Posts: 137
Likes: 0
From: Sweet Home Alabama!!!
Originally Posted by SpAm@FC
@5252

only 4 info...

if you crank your engine with a socket an without plugs you should here every half turn a "plop"...

on 3 full rotations you should hear 6 pops... if you only hear 4 pops you have blown 1 apex... if you hear 2 pops you have blowed one apex in the front and one in the rear housing! if you hear 3 pops you have killed at least 2 apex or all three apex in one housing
I meant 3 pulses per housing, cause when your doing a compression test, your only testin one housing lol. If there is only two pulses you have 1 bad seal, in that housing, 1 pulse you have two bad seals, and so on.

and i only meant to turn it over with a socket while pouring the ATF in, so he will know when the rotor has truned enough for him to pour in more.

Last edited by 5252; Mar 2, 2005 at 11:50 PM.
Reply
Old Mar 2, 2005 | 11:56 PM
  #17  
5252's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Feb 2005
Posts: 137
Likes: 0
From: Sweet Home Alabama!!!
Originally Posted by drft_180sx
^^Sorry to thread jack....but what if you get 5 pops??? My car has been sitting around cause i thought i blew an apex seal...

FRONT_________REAR
..Pop
.............................Pop
..Pop
.............................Pop
..Pop
.............................Silence!!

Repeat cycle....
one of the compression points in your rear housing has no compression lol. It sounds like you just have one apex seal on the rear rotor thats carbon locked. Have you done a compression test? If so, whats the compression for the other pulses?

Try the "ATF trick" as i descrided before. You should have 3 pulses per rotor for every revolution of the E shaft.
Reply
Old Mar 3, 2005 | 07:42 AM
  #18  
fong's Avatar
Rotary Enthusiast
iTrader: (77)
 
Joined: Oct 2001
Posts: 1,197
Likes: 3
From: Maryland
so far, there are 3 methods to try to restore the lost front compression. ATF, mineral oil, and 2 stroke oil? would someone summerize the pros and cons for each? or which is better than the others two?
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ZacMan
Build Threads
4
Sep 19, 2015 09:20 PM
Monsterbox
Adaptronic Engine Mgmt - AUS
5
Sep 11, 2015 03:29 PM
ZaqAtaq
New Member RX-7 Technical
2
Sep 5, 2015 08:57 PM




All times are GMT -5. The time now is 04:45 PM.