Maxtanner1

So I probably brought this on myself and should just give up and take it into a shop that did tell me they would work on old rotaries. But basically I put a 1982 12A with a stock nikki carb that ran perfectly into a 1974 RX-3. In the RX-3 there is no wiring for the rat's nest solenoids, air pump, A/C, etc. so that was all removed and I followed the rat's nest removal pdf guide from RX7 club, plugging up what they said to and making block off plates. The port on the back of the carb that is supposed to go to the exhaust is still open, but i think that sends air, does not suck it in, and there's a port below that that's just as big that does take in air but was plugged by a hose and bolt the way I got it and it ran fine... Anywho the issue is that it runs decently with the choke pulled at full, half, and 25%, but as soon as I push the choke back in it just instantly dies, sometimes with a little backfire, but bam, just dead. I've also tried changing the air/fuel mixture but doesn't make any difference at either end of extremes (lean/rich). Then I can start it right back up again as long as the choke is pulled. So I'm thinking HUGE vacuum leak somewhere or fuel delivery. Anyone have any ideas of what to try next?

REBELDE

If you took distributor out. Check timing. Also check for spark in all 4 spark plug wires.

Maxtanner1

We never removed the distributor, but we did remove the cap. Would it be a spark problem if it works with the choke?

Maxtanner1

I should also mention that I can drive the car without the choke pulled as long as the rpms stay above about 2500

REBELDE

vaccum leak. BIG *** ONE.

Maxtanner1

Does the place where the air pump was attached suck in air? We put on a block off plate with some silicone, but i was under the impression that sent air to the pump, not the other way around. I know you can test with some carb cleaner, spraying around suspected areas, but doesn't the choke cut off the air intake all together, so even if I sprayed the cleaner to listen for a stutter, it wouldn't work right? Or am I not understanding the choke system correctly?

REBELDE

take a picture and i will tell you exactly what needs to be capped. Also the nikki must be converted to mechanical secondaries since they originally controlled by vaccum.

Maxtanner1

Maxtanner1

Please excuse the shotty plug work, I've just been trying so many different things to make it run right. Here you can see at the back there is the missing hose between the back of the carb and exhaust Which I didnt think mattered) and where the white golf tee is used to be connected to where the hose with the screw in it is near the bottom, but it was connected with this funky orange colored permeated connector. Also you can see at the back near the bottom there's a BIG hose plugged with a big bolt.

Maxtanner1

Here you can see the six little ports on the bottom of the carb, from left to right:

1-plugged properly
2-valves for distributor
3-bottom of little black valve (i forget the name)
4-top of little black valve
5-plugged properly
6-plugged properly
Then just to the right of all the little ones is a big one that has been plugged with what I had laying around
The thicker hose goes from the oil pipe vent to the little black valve, then the top of the carb.

The guide from rx7 club said something about two little metal vacuum lines that needed to be crimped but I cant find them for the life of me... Also which valves are the secondaries?