mikexj1020

I bought an 85 Rx7 that has not been registered since '99. The last time it was started was 3 years ago. I got the gas tank boiled out and sealed, new fuel pump and fuel filter. I haven't changed the spark plugs or tune up anything yet.

The car will start if you pump the gas pedal a few times. Once its running with your foot on the gas or the choke out it runs really good. It doesnt miss and it will rev to 7 grand. As long as my foot is just slightly touching the gas it will stay running and again it runs amazing.

Now I am looking into rebuilding the carburetor. I did spray starting fluid all over the engine when it was running and didnt rev up any. What else could be a culprit to this problem. The PO didnt know how to work on cars and I doubt the carburetor settings were changed but who knows. What could I adjust or look into.

Thanks in advance!

-Mike

Krathion

Mine sat here for about 6 years same problem it could possibly be a vacuum leak but i doubt it. Its probably in need of a rebuild its kind of a daunting experience but after when its running good you will be glad for the effort autozone sells a kit wich is recommended by a few people on this forum its called the GP sorenson kit I believe. Alternatively as a stopgap fix run some carb/injector cleaner in your gas and a couple cans of spray cleaner through the carb while its running you may be able to get your jets to loosen up with a couple light taps on the side of the carb with a hammer just be gentle and good luck

mikexj1020

Okay thats sounds like a good idea. It couldnt hurt I suppose. I bought the haynes manual online today for this car, I have read some quick write ups about rebuilding the carburetor but I wish there was a pic intensive one. ...Maybe ill make one if I do the rebuild. It seems intimidating but everyone says its not that hard just alot of work. The motor runs so good and I have only let it run for a minute or two max and should prolly run it for like a good 10-15 minutes and see how it is from there.

DivinDriver

iTrader: (15)

Most likely your idle circuit in the carb is gummed up. You can try hosing it out with carb cleaner spray, or running seafoam through it, but
if it's really gummed bad, a rebuild is the only way to set it right.

Keys to a painless carb rebuild are:

Attention to details; document everything, keep track of all the little bits, read instructions first.
Cleanliness; you can't get the thing too clean.
Patience; don't rush. Don't mess with your float levels at all unless you prove they are off. Expect it to flood a couple times with new needles until they break in.

It's not that hard. It will reward careful work and punish sloppiness, though.

74RX4

iTrader: (10)

Check this hose carefully.

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

mikexj1020

- Thanks 74RX4 I will be looking into that tonight when I get home.

- DivinDriver Does the carb rebuild kits come with instructions? Like an exploted view of everything? I think I could be able to do it but easier said then done. I dont really know anything about carbs I knows theres jets, floats, and a whole bunch of stuff going on.

I cannot believe how good the car runs when my foot is on the gas just a little bit or choke pulled out. It runs strong but just wont stay running lol.

Thanks

DivinDriver

iTrader: (15)

They do, but the Mazda Carb Manual you can download from here in the forums is far, far superior.

Covers tons of theory and explains how things actually work in the carb, too. Highly recommended reading! https://www.rx7club.com/1st-generation-specific-1979-1985-18/download-copy-your-year-fsm-click-thread-get-link-894736/

It could be just that your idle settings are messed up; I'd check them out before diving into a full rebuild. There are detailed threads on the subject hereabouts.

mikexj1020

Thanks for posting that thread however the link http://rx7.foxed.ca/ isnt working. I dont think its b.c of the proxy set at my job. If you can access it let me know maybe i can only check from home.

Thanks

patmac6075

iTrader: (26)

What he said^^^

Have you tried raising your idle by turning the idle adjustment screw?

mikexj1020

No I have not, I dont know what screws to adjust. Im still researching that. Dont you have to adjust the idle screw and another one at the same time?

mikexj1020

http://www.ausrotary.com/viewtopic.php?f=4&t=139171

Okay so I see there is the idle screw and air adjust screw. How should I go about adjusting them. I know you all think I am noob which I am with this carb stuff.

Thanks again guys!

RX-7 Chris

iTrader: (19)

This should work for you:

http://foxed.ca/foxed/index.php?page=rx7manual

mikexj1020

yeah somthing with the proxy at my job has it blocked i got it on my iphone so should work at home

Thanks again!

DivinDriver

iTrader: (15)

First step of adjusting those screws is make sure you know how to put them back where you started.

Mark position, then turn them in to (lightly) seat closed, while counting turns. Then put them back to square one before you start adjustments. Will save you much hair-pulling if you lose track of position mid-changes.

mikexj1020

Okay so not much progress on tuning the carb. I found the throttle adjust screw. Unscrewed it left 1 full 360 degree turn and no changes, didnt have much time and so much crap in the way. However I was curious if the "butterfly flap" for the primary jets is suppose to be open all the time and if could seize? I added a photo for reference. Also the solenoid connected to the linkage on the opposite side moves, but the linkage doesnt. However I am unsure if its suppose to even move.

Also which direction do i need to turn the throttle screw to run with a higher or lower idle?

Sorry for the noob questions but we gotta start somewhere.

Thanks!

patmac6075

iTrader: (26)

The "always open" one is the choke. It should be open unless of course you have the choke pulled out.
I believe the other thing circled is the Hot Start Assist....many people remove it, and for right now I don't think it's causing you any problems.
Finally, to raise the idle you should "tighten" the idle adjust screw. (Righty tighty...Lefty lucy)

mikexj1020

Okay well the always open choke stays in that position all the time whether the choke is out or not. However the choke seams to work because it will run with it out. Or it will run with my foot on the gas. When the car is running with the choke out and if it's like at 3000rpm I can lower I to 2000 or so by manually pushing the choke putton in, not all the way in or it stalls. (the butterfly flap never moves)
Now there is a motor by the master cylinder that goes off when the car is warm and I try to start it but I'm guessing the other end is stuck. That I beleive is the hot start assist.

I still have to pump the pedal to start it and leave my foot on the gas to keep it running or have choke out.

Also should I adjust the idle mixture screw with the no tamper shell on it or the throttle adjust screw which does not have a no tamper shell on it.

Thanks for all input!

patmac6075

iTrader: (26)

I believe the butterfly my not be hooked up correctly...what is happening when you pull the choke **** it is raising the idle speed (which it should be doing). So looks like you have a problem with the butterfly (but that's not affecting you right now).

the adjustment screw with the tamper-proof cover is the mixture screw You can leave this alone as well if all you need to do is raise the idle speed. The idle speed screw is to the right (not always easy to find). Me personally, I would give it three (3) complete turn (to the right) and then adjust down from there. Or you could play it safe and adjust one (1) turn at a time. Just keep careful track as DivinDriver said.

Have you read the manual? Much of what you're asking is covered.

mikexj1020

She idles now! Thanks everybody! The car overheated though so prolly needs a flush and a thermostat. Hasnt been changed in 12 years so its expected. Still needs a brake line and a few odd and ends and she will be on the road

Thanks! you guys are all very helpful

DivinDriver

iTrader: (15)

Congrats; you're on your way to a full-blown rotary addiction now.