I haven't seen this problem discussed on my search of the threads. The car: '85 GSL-SE The problem: Once or twice a year engine cranks, no start, then smell of gas and flooding. If left for 24 hrs, will start sluggishly, catch. produce great cloud of white exhaust, then run smoothly, start promptly and no problem for 3 to 6 mo. Battery is good and cranks quickly, recent tune. After the third tow to the third mechanic with "nothing but flooding as the cause", Ken Durkee, Mazdas and more, Kent, WA, quickly identified the problem and inexpensively fixed it with a fuel pump cut out switch mounted on the dash. Now, when it occasionally won't start with flooding, I flip the switch, continue to crank for 15 to 30 seconds, it catches, switch on, and I am on my way. It is also a great anti-theft device.

 

Maybe you didn't search the right terms or the right section, but hot-start issues are very common on S4s (2nd gens), which share a lot in common with the EFI 13b in a GSL-SE. A fuel cut switch is a band-aid, but it can be effective. The real fix is adjustment of the starting fuel map, but that requires and ECU you can program.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/looking-car-has-hot-start-problems-499744/
https://www.rx7club.com/rtek-forum-168/starting-fuel-map-886098/

 

I think the most likely cause of your flooding after sitting for long periods of time is either a leaking fuel injector, or water seeping into the housings. A quick sniff of the white smoke would narrow this down...

If it is leaking injectors, then they can be removed and sent out for cleaning but its not cheap. However, the fuel cutout switch can get you by, just switch the pump off before shutting the car down. This will empty the fuel rail/injectors of fuel, so there is nothing to leak out of the injector(s).

If you have a slow water leak, then there is a product called Alumaseal which will become your new best friend.



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The GSL-SE is notorious for flooding after it's started up, then shut down without a proper warm up, as would happen when just moving it to another spot on the driveway. If I ever want to move mine, say, from the driveway onto the street, I'll drive it around a bit before parking it.

 

If you decide to send out your injectors for professional cleaning you should try Witch hunter. I haven't used them, yet, but members on this forum have said they are a good company to use and for all 4 injectors it only costs about $100, about $100 less than brand new ones. They even send you the flow test results from before and after the cleaning.

 

Dirty injectors will make the situation worse, but they're not the root cause. Mazda's start map is excessively rich under warm conditions, and it will flood from time to time. On lower compression rotors, or high-mileage engines that have lost some compression over the years, the problem will be even more prevalent.

I posted a link to an Rtek thread showing the map. I inject 3x less fuel under warm/hot conditions, and the engine never floods. If I put it back to stock, it floods occasionally.

 

Thanks for the help. You are right about the limited search. I looked only at 1st Gen. If the problem happened more than once or twice a year, it would be worth some serious attention, but the band-aid works very well, unless my plugs are fouled and need replacement

 

the white cloud sounds more like a coolant leak, may need to go to a zero pressure system, or try the alumaseal route mentioned above.

The root cause could be dirty and therefore leaking injectors too. The easiest flood fix isn't to cut the fuel pump, but the trailing spark ignitor. Pull the blue wire off the trailing ignition coil and it'll fire right up within a few seconds - then reconnect it and you're good to go. I added such a cutout on my GSL-SE and it worked perfectly, even though it was only a random flooding event.