Mazda RX-7 Starting in the 1970s, the uniquely powered RX-7 helped put Mazda on the performance car map.

87 rx-7 n/a starts but won't run

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  #1  
Old 07-01-2008, 11:37 PM
dnelson's Avatar
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Default 87 rx-7 n/a starts but won't run

I was given an 87 n/a rx-7 that quit running. i don't have much history on it, just that it may be a new or rebuilt engine. it starts but will not run unless i spray starting fluid in the intake. ifound another post that talks about the air flow meter and the intake gaskets but have not checked yet. i also need to know about the apex seal, where it is and what happens when it goes out. the car has been sitting for at least two years so any other advice on getting it running would be greatly appriciated
 
  #2  
Old 07-02-2008, 04:31 AM
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Default RE: 87 rx-7 n/a starts but won't run

yeah, more than likely an apex seal. if it sat that long, one or more apex seals probably got stuck and destroyed.
 
  #3  
Old 07-02-2008, 08:20 AM
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Default RE: 87 rx-7 n/a starts but won't run

so what does this apex seal do and how hard is it to change? thanks
 
  #4  
Old 07-02-2008, 11:53 AM
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Default RE: 87 rx-7 n/a starts but won't run

The Apex Seal in a Rotary engine acts like a piston ring in a piston engine. It forms the seal between the Apex of the rotor & the housing. If you do have any bad Apex seals, you would be looking at a complete engine rebuild.
 
  #5  
Old 07-02-2008, 04:51 PM
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Default RE: 87 rx-7 n/a starts but won't run

so is there anything else i can check before i dig in to it? the air flow meter is not stuck and the intake gaskets look ok but that doesn't mean much. I've completely torn down and rebuilt a big truck motor but i'm feeling kinda helpless on this little thing. once again thanks for all your help!
 
  #6  
Old 07-02-2008, 07:24 PM
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Default RE: 87 rx-7 n/a starts but won't run


Rotary'sare a breed all their own and w/o the proper tools and training would not attempt a driveway repair, if I wuz U.
That said, why would it be an apex seal if the engine runs when starting fluid is applied, guys? It sounds more like a fuel delivery problem to me?
If it's been sitting and has old fuel that'll gum up a lot of things and cause a lot of running problems. Fuel is not that stable over the long haul.It begins to break down almost immediately in fact, and after a year (or even less) is useless.This will even happen to a piston engined car if allowed to sit too long. Believe me. I know from personal experience.
I would try purging and cleaning the fuel system COMPLETELY before going for a complete engine rebuild. Replace the fuel filter, clean out and completely dry the tank, fuel lines, purge valves, etc...

 
  #7  
Old 07-02-2008, 10:33 PM
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Default RE: 87 rx-7 n/a starts but won't run

cool, thank you, thank you all, i kinda thought it might be something like that, but i did drain the gas out of the tank and the lines. i'll do stome work and let you know what happen. meanwhile anybody needs to know anything about cat diesels i'll be glad to help!!! thanks again
 
  #8  
Old 07-03-2008, 07:22 AM
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Default RE: 87 rx-7 n/a starts but won'

Check to make sure that the AFM is is connected & that all vacuum hoses are also connected. These engines do not like vacuum leaks. Thanks.
 
  #9  
Old 07-05-2008, 06:39 PM
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Default RE: 87 rx-7 n/a starts but won'

ok guys, i've cleaned all the fuel lines out, replaced the fuel pump and the filter, and put in all new gas with an injector cleaner in it. it doesn't appear to have any vacuum leaks. i had it running on propane through the intake for about an hour and every time i would try and give it some throttle it would try and die. i've got fuel all the way through the system but it acts like the injectors are not fuctioning. is there a good place i can send them to get them cleaned and tested? also is it possible that the ecm is not working right? it does't seem like that would be the problem since it runs fairly well on propane. anyway, help if you can, thanks.
 
  #10  
Old 07-07-2008, 11:02 AM
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Default RE: 87 rx-7 n/a starts but won'

If it is running on ether & not on it's own, fuel delivery problem. Check the injectors, the pump & the wiring circuit. Also, check to make sure that the injectors are grounded correctly.
 


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