ThirdPedalNirvana

(Stock Nikki California 1985 12A GSL RX-7, all emissions equipment intact and functioning)

For a while now, it's taken an absurd amount of force to pull my choke closed on a cold morning. I-Feel-Like-I'm-Going-To-Break-The-**** force. It doesn't take too much force to get the choke to close enough that the electromagnet holds it closed, but the last little bit where the mechanism props the throttle open on what I'm guessing is a fast-idle cam, this is very hard. On a cold morning, without the fast idle, the car just wants to stall, so I have to use both hands to pull until it engages the fast idle.

Except today, the fast idle decided not to disengage after the engine warmed up. I can pull and release the choke with ease, because it's not actuating the fast idle anymore. The car idles at 3000 rpm always. This is especially disconcerting going downhill, as I'm used to having the car in a gear where the engine is turning below 3000 rpm, and the fast-idle makes the car want to accelerate (so I'm fighting it with the brakes). Leaving the car in neutral is better, but I can feel there is less engine vacuum and therefore less power brake assist. And of course, sitting at stoplights at 3000 rpm is no fun, nor is my fuel consumption.

Trouble is, I don't know where to begin to look for a fast idle mechanism. Does anybody know the construction of the stock Nikki carb, and can tell me where I need to look or what I need to lubricate? I don't know where the fast idle mechanism lives or how it works. I can't even figure out how to actuate the throttle from within the engine compartment.

Seriously, anyone who knows their way around a Nikki can help me. Diagrams are a plus but even a written word description is a help.

t_g_farrell

iTrader: (1)

Carb manuals can be found here: Foxed.ca

The choke cable goes to the top of the carb and attaches to a lever near the rear side of the top plate that actuates the choke butterfly and has a connecting rod to the fast idle. You need to remove the air cleaner to see any of this. Try hitting the linkages on that side with a good dose of carb cleaner and then maybe some lube like WD40 or light machine oil. Work it back and forth with you hand until feels looser.

ThirdPedalNirvana

Thanks t_g_farrell!, I'll be sure to take a look at that.

Unfortunately, after I finished my lunch, I went to drive back to work and I'm pretty sure the engine is flooded. Cranks endlessly, doesn't even start to catch. Car was warm when I shut it off, but at 3100 rpm because of the fast idle, it has quite a bit of momentum and probably sucked down sufficient gas to flood itself.

Gonna ride back home tonight on an AAA truck. I have a feeling this car is going to stretch the limits of my AAA membership.

ThirdPedalNirvana

UPDATE

a few cap-fulls of ATF down the carb did the trick to unflood the engine and spared me a shameful ride on the back of the AAA truck. Anyone who owns a 12a should carry some ATF with them just in case. 2 caps down each primary throat, ignition on, pump the gas 5 times, hold it to the floor, & crank. She started so fast I was at 5000 rpm before I realized it and pulled off the throttle.

Regarding the mechanism, I got the air box off and played around with it. Nothing was broken. The choke cable had slack until I got a flat metal piece unstuck from a screw head and the choke popped open. The whole thing felt grimy and dirty so I hit it with a bunch of carb cleaner and it seems to have fixed my issues. Hopefully it was just dirty. If I had done anything more sophisticated I'd have taken pictures, but I literally just sprayed it with cleaner and worked the mechanism by hand.

Slow idle is up about 200 rpm higher than it used to be (1100 rpm instead of 900), but it's much better than being stuck on fast idle all the time.

So to fix this problem I needed... no tools at all. Spring clips on the air box lid, One wing nut holding the air box on, all 6 hoses on the bottom of the airbox are just pressed on. Can of carb cleaner. My RX-7 might break more often than my 300zx but it certainly doesn't take nearly as much effort to fix.

RotaryRoadkill

I just got my 7, with a leaky carb, rebuilt it myself fairly new to the rotary. The Nikki is really simple, nice to hear there are still running FB's around Cali If you do rebuild the carb, its very simple but I learned, the hard way it is much easier to install the intake/carb as a pre assembled unit, I removed them all piece by piece and changed the carb gaskets. It runs great now, Just need to fix my oil leak(s) The Nikki is very easy to tune as well just Idle and Mixture, just wondering does your car make the occasional "poot-poot" noise at low engine speeds? I seemed to be able to tune it out to run really smooth. After rebuilding the carb and tighening the throttle cable, the car is faster, because I have more pedal to put down. Now I can ding that buzzer

ThirdPedalNirvana

Yeah my car does occasionally "poot-poot" (which is a lovely way to describe the sound of a misfire, as opposed to the "pop-pop" of extra fuel being exploded in the exhaust reactor chamber on overrun) but much more so when it's cold out. Once I've gotten her warm and ripped up over the mountain, it's very rare.

RotaryRoadkill

We just got the car back together and running the other day, it wanted to fast idle at 3000 also, got the idle a little low right now, going to bring it up to 1000, I bogged it at a stop sign with a car behind me, and It hadnt quite warmed up yet. My first experience flooding the rotary, did just what my dad told me and it fired right up and burned out away from the sign
I think that the poot has something to do with being rich/lean in the cold or something. I have to fix the cars leaks, and it will be awesome. (Leaks Oil from everywhere ,and Coolant from the intake.) Just changed the Intake Gasket when I rebuilt the carb. So I have to take my intake back off and re-reseal it. Redoing the oil lines and the whole oil system(Pan Gasket etc.) trying to fix the oil leaks. Drove the car today and came back steaming oil smoke, so I won't be driving it alot until I fix it, planning to daily drive it once its sealed