hawley2373

My RX is a 1983 bone stock, 65K miles, auto trans. Was running like a clock. Left sitting for 2 weeks now 4bbl don't seem to be working and when they do open there is a delay in them closing which is a little scary when you dont have your foot in it and it wants to continue to accelerate.
Are the 4bbls opened mechanically or by vacuum? Any obvious things I can look for. Starts and runs great except for wide open. Thanks!

Rx-7Doctor

iTrader: (13)

If you are stating that the throttle is wanting to stay open then you need to inspect the throttle cable for binding.

The secondaries are vacuum operated so they should not be a factor.

hawley2373

I haven't had the air cleaner off yet but it does seem like the accl. is sticking but it doesnt act like the cable is binding. It feels smooth. When I go to wide open throttle the secondarys don't open every time but when they do come open and I let off there is a couple second delay before things slow down. I do plan to pull the air cleaner and give things a visual once over.

81gen1

i had this broblem, turned out to be my throttle return spring was weak, but my seccondaries were seised shut from sitting for about 10 years.

Rx-7Doctor

iTrader: (13)

Disconnect the choke cable and the throttle cable from the carburetor and open and close the throttle to verify the butterflies are not sticking.

hawley2373

Finally got a chance to look at my carb on Saturday. Though the more I drove it the better the thing started working. Pulled air breather and could not see where the choke or accl cable were binding. Both move in and out freely. I sprayed the inside and outside of the carb really good with carb cleaner and poured some Sea Foam in the gas tank. I would love to get that carb off to kit and to remove that tamper proof cap on the mixture screw. It looks like an act of congress to get the thing off. I can see the two mounting nuts on left side but I can't see nothing on the right. It almost looks like it would be worth money to take to a shop to have done. I guess I will do some reading up over the winter and do something in the spring. My car is getting layed down to rest today for the winter. I rented a garage to keep the nasty South Dakota winter off it. It sucks to think I won't be driving it for 5 months.

Rx-7Doctor

iTrader: (13)

This should help with the carburetor removal.

https://www.rx7club.com/1st-gen-archive-71/fuel-intake-10-minute-removall-nikki-carb-448284/

As far as the tamper proof mixture screw. There is no reason to touch the mixture setting.

hawley2373

Thanks for the link on carb removal. I'm hoping it wont be as difficult as it looks. I thought cleaning the carb was going to do it but the 4bbls still dont open consistanlty. As far as the mixture screw, I realize that has nothing to do with the 4bbls not working. I thought I could get the idle to smooth out just a little better.

hawley2373

This is maybe a few years late but I wanted to post this in case someone else runs into it. The vacuum port that feeds the secondary vacuum diaphragm was plugged with carbon. It would allow vacuum to get through to pull the secondaries open but then when you let off the throttle it took some time for the vacuum to bleed off because the port was blocked causing the secondaries to stay open.

Kentetsu

Wow, thanks for posting your solution. Even late, I'm sure it will help someone in the future.




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