New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

No Idle Rx7 Gsl 1981

Thread Tools
 
Search this Thread
 
Old May 18, 2011 | 05:05 PM
  #1  
Cullen26's Avatar
Thread Starter
Junior Member
 
Joined: May 2011
Posts: 6
Likes: 0
From: Wheaton Mn
No Idle Rx7 Gsl 1981

Hi everyone I just joined the rx7 club

My rx7 will start up and run with the choke on and run roughly but when it warms up

and the choke turns its self off and the car dies
Reply
Old May 19, 2011 | 11:08 AM
  #2  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Good reading on carb adjustments: www.sterlingmetalworks.com




.
Reply
Old Jun 7, 2011 | 02:38 PM
  #3  
Cullen26's Avatar
Thread Starter
Junior Member
 
Joined: May 2011
Posts: 6
Likes: 0
From: Wheaton Mn
Originally Posted by Kentetsu
Good reading on carb adjustments: www.sterlingmetalworks.com




.
Sorry I have not replied for a while I had a mechanic who has never worked on a rotary engine before rebuild the carburetor but maybe he did it wrong but it was having the same trouble before it got rebuilt.
Reply
Old Jun 7, 2011 | 05:11 PM
  #4  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Start looking into the ignition system. Begin by confirming that all spark plugs are sparking. Ignition issues often look like carb issues...
Reply
Old Jul 2, 2011 | 12:09 AM
  #5  
maxwellt91's Avatar
Maxwellt91
 
Joined: Jun 2011
Posts: 28
Likes: 0
From: Englewood, Colorado
I dont think it would be the ignition system because if it was the car would most likely not start at all with the choke on or off. Your idle speed or fuel mixture may not be set right. I would mess with your idle speed screw first and see if you can solve it
Reply
Old Oct 10, 2011 | 05:59 PM
  #6  
Cullen26's Avatar
Thread Starter
Junior Member
 
Joined: May 2011
Posts: 6
Likes: 0
From: Wheaton Mn
Now the car wont even stay on even if I try. It runs for about 10-30 seconds and dies. I try to keep it alive by pumping the gas pedal but it doesn't work I just here a air like sound that goes psst psst psst.

I took off the spark plugs and put Marvel Mystery Oil into the engine and let it sit for 24 hours.

I started it up making the biggest white cloud come out of my tailpipe. The car died a few times but after 5-10 minutes it was running a lot better and actually idled with

smoke coming out of the I think catalytic converter or exhaust manifold but after about another 10 minutes it would not idle but it did run.

So the next morning I try to start it up and I could not keep it running for a minute unless I pumped it 20 times. I also cleaned the spark plugs.

I checked through the window of the carburetor and it was empty

So I am now guessing this is a ventilation issue, Carburetor issue, or a vacuum leak I cannot find. I will maybe try to adjust the carb but my tachometer went out when I hit a bump.

Last edited by Cullen26; Oct 10, 2011 at 06:03 PM.
Reply
Old Oct 11, 2011 | 04:55 PM
  #7  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Could be the fuel pump, can you hear it running when you turn the key on?
Reply
Old Oct 11, 2011 | 04:58 PM
  #8  
Kentetsu's Avatar
Lives on the Forum
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 11,359
Likes: 14
From: Grand Rapids Michigan
Originally Posted by maxwellt91
I dont think it would be the ignition system because if it was the car would most likely not start at all with the choke on or off. Your idle speed or fuel mixture may not be set right. I would mess with your idle speed screw first and see if you can solve it

Wrong...

A freind and forum member Man in Black installed a new motor and came by to show me. The thing sounded like it was ported, but it wasn't. Ran like a raped ape, but felt funny at the top end. I looked it over and saw that he had leading and trailing reversed on the rear rotor.

A couple of years ago, after a fresh motor install, car was running fine but I was having a tough time eliminating spark knock at high rpms. That was my only indication of something wrong, and it was barely noticeable. Eventually found that my ignitors were running to the wrong coils, so leading and trailing were reversed. I actually won a few autocrosses like that.

So yeah, you can totally screw up the ignition wire routing and still have a car that runs "almost" right.
Reply
Old Oct 11, 2011 | 06:29 PM
  #9  
BASTARD's Avatar
®
Tenured Member: 20 Years
iTrader: (4)
 
Joined: Dec 2003
Posts: 2,282
Likes: 3
From: NorCal
First check that you are getting fuel...

always be careful when working with gas/fuel... always disconnect the ignition to keep it from sparking an explosion.


disconnect the fuel feed line line at the carb and place in a catch bottle

turn the key to the on position and see if fuel fills the catch bottle

if it doesnt fill the catch bottle, you have a fuel feed problem... bad pump, clogged line or filter or out of gas

if it does fill the bottle... then re-connect the fuel line and check float bowl levels, they should be in the middle of the sight glass (check both floats)

if no fuel in float bowl you will need to take the carb apart to verify the needle and seats are working

if you do have fuel in float bowls, then check accelerator pump, you should see fuel spraying into the primaries every time you actuate the throttle

if you dont see fuel spraying in, you either have crap in your carb or a bad accelerator pump... carb needs a rebuild with a quality rebuild kit from a mazda parts store like mazdatrix

if all of that checks out, check for vacuum leak... you probably have a vacuum leak from the joker who previously rebuilt and/or installed the carb.

.... you will need a new set of plugs as your old ones are surely fouled beyond foulness
Reply
Old Oct 12, 2011 | 06:20 PM
  #10  
Cullen26's Avatar
Thread Starter
Junior Member
 
Joined: May 2011
Posts: 6
Likes: 0
From: Wheaton Mn
Originally Posted by Kentetsu
Could be the fuel pump, can you hear it running when you turn the key on?
Its a new fuel pump and I can here it when the key is on
Reply
Old Oct 12, 2011 | 07:09 PM
  #11  
Cullen26's Avatar
Thread Starter
Junior Member
 
Joined: May 2011
Posts: 6
Likes: 0
From: Wheaton Mn
Originally Posted by BASTARD
First check that you are getting fuel...

always be careful when working with gas/fuel... always disconnect the ignition to keep it from sparking an explosion.


disconnect the fuel feed line line at the carb and place in a catch bottle

turn the key to the on position and see if fuel fills the catch bottle

if it doesnt fill the catch bottle, you have a fuel feed problem... bad pump, clogged line or filter or out of gas

if it does fill the bottle... then re-connect the fuel line and check float bowl levels, they should be in the middle of the sight glass (check both floats)

if no fuel in float bowl you will need to take the carb apart to verify the needle and seats are working

if you do have fuel in float bowls, then check accelerator pump, you should see fuel spraying into the primaries every time you actuate the throttle

if you dont see fuel spraying in, you either have crap in your carb or a bad accelerator pump... carb needs a rebuild with a quality rebuild kit from a mazda parts store like mazdatrix

if all of that checks out, check for vacuum leak... you probably have a vacuum leak from the joker who previously rebuilt and/or installed the carb.

.... you will need a new set of plugs as your old ones are surely fouled beyond foulness

So I tested the fuel line by putting it in a bottle and turning on the key and there was gas being pumped into the bottle.

The mechanic told me that the carb does have a broken accelerator pump

I know the spark plugs are fouled but I do clean them but I should probably get a new set.

How do I check both float levels? Can you see them both through the window on the carb?
I checked the window and it is usually very low
I could not get my car stared because my battery is a little weak but right now the level is below half.

Last thing what is a good way to check for vacuum leaks?
Reply
Old Jun 9, 2012 | 10:11 AM
  #12  
Cullen26's Avatar
Thread Starter
Junior Member
 
Joined: May 2011
Posts: 6
Likes: 0
From: Wheaton Mn
Many months late I've found the problem. It was just a pinched gas line. I also put on a different (used) carburetor but now it idles at 2000 and warms up at 4000 and when I turn it off it backfires like a 12 ga. any suggestions on what I should do?
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Kyo
2nd Generation Specific (1986-1992)
6
Apr 13, 2019 09:24 AM
smikels
Rtek Forum
4
May 12, 2016 12:34 AM
kenplevy
Introduce yourself
2
Sep 4, 2015 10:40 AM
ncds_fc
New Member RX-7 Technical
1
Aug 15, 2015 10:06 AM
KAL797
Test Area 51
0
Aug 11, 2015 03:47 PM




All times are GMT -5. The time now is 05:41 AM.