Azederach

Hey all ! I just did my first nikki rebuild, had water from tank gum up the fuel, lots of white gunk. Cleaned and replaced all parts after blowing channels out, fixed new gaskets as they lacked a few holes. Reassembled. Started right up, won't drop below 1.2k. Been checking all vac lines. Pity there's no clear write up about locations for those. Takes forever to trace each one from FSM docs. The only other suspicion I have is that I attempted to pull the front sec butterfly because there was gunk and corrosion in the housing - and scored the edge a bit. Reassembled so it closes flush, but I don't know. I tried to cover the front secondary barrel to rule this out as my leak, but engine immediately dies. Opinions ?

Oh yeah, I also haven't got the hot start spring in yet, but forcing the throttle closed by hand doesn't help. I haven't adjusted the dashpot or idle speed screw, either. the throttle cable has been ruled out.

Benjamin4456

Secondary's being stuck open will often result in a rather uneven and high idle unless you have the mixture screw turned way out (baseline is 3.5 full turns from seated). It's definitely possible and I've had the issue myself after a Nikki rebuild as it can be difficult to get them to sit perfectly flush in there.

My honest suggestion is take it back off and separate the throttle body again as it's a sure fire test. Hold it up to a light so that you're looking through the butterflies. There should only be a very very tiny sliver of light leaking past the secondary butterflies. If the blades look like they're well sealed then that rules that out and back to vacuum leak hunting it is. The only other possible issue related to the secondaries would be if one of the linkages is tweaked and holding them open a hair, but this is rather unlikely.

There are also a number of routing diagrams for the rats nest available online. Just look up "[year] rx7 vacuum diagram" and some colorful photos should pop up (some may not be in color). They do vary year to year, as well as if it's a Cali or Federal model so keep that in mind.

Azederach

Thanks. Turns out I flooded it, probably by closing of the secondary barrels. My plugs are kind of black (and wet) and I have a burnt coil wire, my cap and rotor are worn, and my 1 1/2yo battery doesn't crank for more than a minute. Off to round up parts.

Azederach

I have the nice colorful vac diagram from the forums, but it doesn't tell me much about the passenger side of carb. took some figuring and research to remember where the alt. compensator, choke diaphragm, etc connected. Now I have photos of where all ends connect.

Likely I'll have it memorized soon...Until next time. I'm over 50 now.