my 1989 rx7 smokes when started cold. the smoke gos away after a few minuts. it dosnt smoke when i take it up to 7 grand and it has no problem getting there. but it dose run ruff when first started. and its hard to start. playing with the gas helps but its wierd. the smoke smells like gas at first but then im not sure. could someone please help me figur out where this smoke is coming from and why my car is hard to start. thank you.

 

new the rotarys so im not even gonna try to help you haha but i have heard that smoke on a cold start is normal. as far as being hard to start and running rough im not sure. youll have to wait for one of the experts to reply

 

well thank u for shereing what u do know

 

If you are located in a colder area then sometimes the Cold weather start will kick in.
I know that Up here(Canada) my N/A had a tendency to smoke a touch on start up.
..
The roughness when first started could also be a fuel issue.I am thinking leaky injectors(slight leaking) causing a bit of fuel to enter the internals.Just enough so that you can still start up but a bit too much that it can effect it when cold.
(it's not a 100% diagnosis,but a guess that has merit!)

 

Also Im thinking it could be the oil control rings/seals. When they start to wear depending on their condition oil slowly seeps past (or fast but thats when they are basically gone) them causing the car to smoke alittle. Especially when the car is cold, the seals arent expanded letting more oil seep past and when you start the car the oil is heated and burned causing the car to smoke. Once it warms up the seals expand and the oil leaking is slowed down or stopped. Im not 100% on this either but sounds familiar.

 

Oil control rings would show "their age" at 7k...be a Fog show out back.(heh.I can still remember foggin an Old Farmer off the road with my Little N/A when I passed him!..lol!)
OP said it smelled like fuel so I am Guessing injectors.

 

Rotary engines have a tendency to smoke on start up in cold weather or if your engine is slightly flooded. If the smoking doesnt stop after a few minutes you have an issue. The rough idle is probably caused by the cold start system mine idles a little rough aswell but, rough idleing could be caused by one of a million things. Does it idle rough all the time?

-May i remind you that rotary engines can be tempromental probably have leaky injectortors or something of the sort. The gas smell is probably from the access fuel leaking in your engine and not quite being burned off.

-Justin

 

@misterstyx69, I was thinking either injectors like you said or oil control rings. I read the part where he thought it smelled like fuel but sometimes its hard to be sure just from the smell coming from smoke especially if its only for a few minutes. If it is the injectors that kind of sucks because now the upper intake, throttle body, and all have to be taken off just to get to them. I remember when I changed my injectors for the first time (I had the 3,800 rpm hesitation and suprisingly it was my injectors) I couldnt find the injectors that were on the block because they were completely hidden by the manifolds lol. All I had was the Haynes manual and they only show the pictures after the manifolds are off so I was confused. Now itd take me 2 hours at the most.

 

It sounds like a seal/gasket problem to me

 

A gasket leaking would contribute to a rough idle but it can also be a million things. Any of the vacuum lines can be added in to that too. It could be something as small as a pin hole making it nearly impossibe to find. The more I think about it the more I think misterstyx69 is right. An injector or your injectors are stuck open dumping too much fuel. The only thing that makes me doubt that is that if said injector/s was stuck open Id think it would smoke the entire time the car is running not just at start up.

 

it only runs rough for a few seconds right when it starts. and it only dose this if the engian isnt warmed up. another thing iv noticed is a replaced bar in the front of the motor. its connected to my throttle and something eles near the bottom of my motor. where its connected at the bottom is to a lever next to little gas lines (i think there gas lines). the bar is messed up. im not sure what the bottom lever dose. it pulls down agaist the trottle. and some times giving it gas will help it start. i thought that should atomaticly flood it.. ? .. how do i check to make sure its my injectors if that is the case? [ thanks to everyone that is responding ]

 

that bar,is the linkage to the Oil Metering Pump.(little oil lines NOT gas)
Make sure that when you open the throttle that it is allowing the OMP to function.
Look for a Thread on how to adjust that linkage.

 

ok. so iv done a bunch of work and found out its coolent getting into my combustion chamber. im not sure if its both rotors. my front rotor spark plugs are more fouled up tho. dose this mean an automatic rebuild?

 

whats up man, smoke could mean a number of different things. Heres a quickie list from what ive seen from mine/my buddies rotaries over the years as weve worn motors out.

1. Black/Dark Smoke = the motor is running way too rich
. Break out a Factory Service Manual and give her a good servicing/tune up!

2. Light/Blueish Smoke = the motor is starting to burn oil. Itll be ok for a while (one of my 1st gens did that for over a year before i sold it).

3. White/Light Smoke - the motor is burning water/coolant. Itll also have that "sweet" coolant smell like when you have a coolant leak under the hood from a leaky hose or something.

Being from So Cal I cant really comment on cold weather start up. It rarely gets into the 50s out here. Good Luck!!!

 

yea. but its deff coolent smoke and iv been told that the only way to get to that seal is to tear down the engine.

 

Is it not true that water can condense in the exhaust system at night, and cause some "Smoke" or steam to rise out the back of the car? I know one of the by-products of an exhaust system is water, so this might have something to do with it being weird at start up. The rough idle could also be caused by the engine not being warm yet, even with piston cars as they warm up and expand they run a little rough too... let us know what you find! GL

 

Is the car overheating? Coolant seal leaks would cause overheating if I'm not mistaken

 

My rx7 GTU sat for three months. I replaced the thermostat, hoses, and radiator. I started it up last night and it smoked a bit. Check engine light is also on. The smoke slowly disappeared but the check engine light is still on. It wasn't like that 3 months ago.