charlie1

My 85 13b seems to run a little rough till warmed up. Is this typical of a rotary engine?
Steve

mar3

iTrader: (8)

In a word, no....you've got a vacuum leak somewhere is my first guess. If it was carbureted, I could guess more accurately, but the 13B is FI, so I defer to the GSL-SE and 2ndgen guru's on further "guessing"...


Mario III

JoeyMazda

To my knowledge, this is typical with rotary engines. I have the same problem during the winter. If you can its best to keep it in a garage or just let it warm up before driving.

mortiky

I'm sure that this condition is not ideal and can be remedied, especially if you are running a stock EFI setup as opposed to a carburated one. But, my 12a with DCOE 45 weber sidedraft carb doesn't do to good in the cold. Kind of hard to start as of recently on the mornings where the night before the temp. was freezing or below, I've been using a little spray of ether on the cold mornings to get that initial start, after that its fine. However, it does seems to run pretty rough for the first minute or two, its like it has to get to that minium temp where the fuel is really vaproizing in the manifold.

mar3

iTrader: (8)

Well, if the 2ndgen gurus are going to be silent, then here's a stock Nikki story. 195,000 miles, stock Nikki never rebuilt, car starts on first try even at 38 degrees F. I start it w/o the choke and set the choke after playing the gas pedal to get to 2500 rpm after seeing the oil pressure pass 30 psi on the gauges. I set the choke to 1100 rpm and the engine spins smooth as silk. I've set my choke rod different than factory specs, though, to compensate for the age of the engine.

All of the above is worthless info if the 13B is EFI, but it's just to prove that a rough idle when cold is not normal for the 12A unless the engine or the induction system has been modded a bit past the line.

charlie1

Wow, well OK, I think Im hearing it may be normal for EFI? Just purchased car, and it, only has 76,000 miles on it. It will be stored in the winter. But it's also the time I wanted to get the car in tip top shape for spring. Is it spring yet? It's an 85 GSL-SE and has never seen salt or rain and had the same owner since 86. Actually, it looks identical to the car on page 61 of the book Sports Car History RX-7. Rotary is new to me, but I'm anxious to learn. Hopefully some of the second generation guys will jump in.
Thanks so much,
Steve

Enthu

iTrader: (1)

if by rough you mean some of popping exhast sounds, i would check and adjust theTPS. The O2 sensor could be at fault as well. how old are and what condition are your spark plugs and wires in?

do you do alot of city driving? if so, try sea foaming! You should strongly consider replacing you water-thermo sensor too, as it about $ 20 and solved a similar issue for me on an S4.

mortiky

correct me if i'm wrong because i'm not super proficient with rotorys, but the O2 sensor doesn't have any effect on the fuel trim until the car has reached normal operating temp. and the computer is running in closed loop operation as opposed to open loop. in fact the O2 sensor doesn't even produce a signal until it reaches approx. 600 deg. F.

Enthu

iTrader: (1)

you would be correct, since it runs normal when warmed up. don't worry about the 02 then, as that wouldn't be at fault.