i just bought a 1984 rx7 12A, sometimes when its running it will just die, it fluds very easy, when i push the gas hard it kinda almost stalls then high revs.

what could the be?

 

ok, i am having pretty much the same deal as you, so i would like to see what's wrong here too.

 

well, i put in engine treament in the oil too for older engines. might have something to do with that since its rotary..i was told the gas tank had sludge in it(this could be gone not too sure he said put a cleaner in before he sold it to me). the carb used to get the grey sludge too had to rebuild the carb, so if you got any suggestion on that please, feel free to help

 

Step 1 address the general tune up items and get that tank cleaned out. Cap rotor wires plugs filter. If its got old gas in it drain the gas and put fresh in. Welcome. There is tons of info here on general tune up procedures and links to the manual.

 

No. 1
Change fuel filter!!! (underside in front of rear left wheel).
If it runs poorly still then the tank sludge is re-plugging it?
Lucky you, yours has a drain in the tank (not so my 1980). But unless you can get whats giving you grief OUT thru the drain, you'll need to pull the tank, have a rad shop chem-dunk and flush it - would advise then re-sealing tank with product like POR15's tank sealer kit. Otherwise insides that are shedding may just continue to do so...
Stu Aull
80GS
Alaska

 

i have a 1984 12 rx7 4b carb...its having trouble starting and if i can get it started it will run with the choke on for about a min the bog right down and shut off...to me it kinda sounds like theres build up in the carb but im not sure..
fluds easy too..
anyone know what my probleme is?

 

Idle mixture too rich, causing the plugs to foul?

 

okay i have a 84 12a...car wont start sometimes, turns over but wont fire up, ive changed sparkplugs and all stayed the same...so i thought maybe the fuel filters clogged, that was not my probleme so i have no clue what the problem is now...

when it dose start....keep in mind its hard to start...as long as you pumped gas before your started it will run for a minute or 2...if you keep pressing the throttle,then all a sudden it dies...
anyone have a clue on what this may be?

 

Check compression, timing, look for vacuum leaks.

Look at the FAQ at the top of the page for more information.

RXDad

 

Have you checked this hose?

https://www.rx7club.com/1st-generation-specific-1979-1985-18/hose-question-750125/

 

i just found out that it is the vaccum pressure thats causeing this probleme...im thinking maybe its a sencor anyone know how to find out?

 

i just went and looked at the afterburn hose, it seems to be fine

i also cant find anything in FAQ...its all about the forums nothing about engines...

 

You are looking in the wrong FAQ. You need to look ing the 1st gen FAQ.

https://www.rx7club.com/1st-generation-specific-1979-1985-18/1st-gen-rx-7-faq-page-237777/

 

Hey, i have a 84 12a 4bbs...im having starting/idle problemes. i have asked before i was told check vaccum hoses compression and do a tune up.. none fixed my probleme...im back at where i started

trouble starting...kinda starts when it wants...
if you start it...it idles at like 250rpm....not good...
you have to keep giving it gas or it will die...
it sometimes boggs down and dies?
it is not the afterburn hose, i have checked
compression is good

this is really starting to annoy me

 

Download the FSM and carb manual from the following link.

http://www.wankel.net/~krwright/cars/rx7/manuals.html

Follow the trouble shooting procedure, then get back to us with a better description of what's happening. In the mean time, what work/maintenance has been done, how old is the fuel filter, are the plugs fresh, are you using the choke, etc..

 

almost sounds like a shutter valve. mine has done that a few times. still sounds like vac to me

 

Did you check fuel pressure and volume flow.

I wish I could get my idle down to 250, are you sure you don't mean 2500

 

fuel filter, change it, less than $5!!

when my shutter went kaput! it made an annoying buzz, and would back fire when deaccelerating.

 

i am sure its 250 rpm and not 2500, fuel pressure is fine, its gotta be a vac probleme thats the only thing else i can think of, new plugs and yes im useing the choke...

 

the carb has been rebuilt, looks brand new...it ran fine until about a month ago..fuel filter is unknown...i have not changed it.

 

Try pulling the plugs after it stalls out.

If they are wet. Try holding a grill/ fireplace lighter to the wet plugs.

hint - gas burns/ coolant/oil won't

 

Alright....

If your engine idles at 250 rpms, then you probably don't have a vacuum leak...

Have you tried adjusting the idle speed? It should idle at about 850, so if you fix that issue you might solve the rest of it too...






.

 

i just replced wire plugs rotor cap ir filter and since it wont idle i held the choke at 1500rpm and checked to see if there was air going into the shutter vaulve and there was no air being sucked

 

i have either a vac leak or shutter vavlue is gone or something..

my car is hard to start wont idle, batorageckfires when decellerating and makes a weird noise sometimes when trying to start almost like a really low squeeking

new wire plugs cap rotor air filter engine treatment new oil and new coolants after i flushed them thats all ive done to the car since it has came out of storage..

 

You can't have a vacuum leak and idle around 250 rpm. Vacuum leaks cause a high idle that cannot be brought down. period. Backfiring on decel can be caused by a a bad decel valve, exhaust leaks, timing may be off or carb is running lean.

Download the carb manual and go through the troubleshooting section step by. You're not providing enough info to diagnose your problem. If you have haven't changed the fuel filter yet, do so or quit wasting everyone's time. If changing the filter shows no improvement, there may be a restriction somewhere in the fuel supply system or the carb may need rebuilt. Start with draining the the tank, cleaning/blowing out the lines and the internal filter screens. 1 screen is at the end of pickup tube inside the tank, 1 under each banjo bolt in the supply lines to the carb and 1 under each needle/seat.

If this car has sat for an extended period of time, a carb rebuild is pretty much mandatory. If you need the carb rebuilt, PM me. I may be a butthead, but I do do good work.
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