dabranco

iTrader: (3)

Hi, I have tried to search but could not find a link for both issues. I own a 1983 rx7 with a 12a I got the car with a badly hard wred fuel pump, this would cause the carb to over fill with gas, I have since replaced the fuel pump with a factory pump and it works great.
So my first problem is the smoke issue, nice and white like a big fluffy cloud, I did a cooling system pressure test and I only lose 1 pound over a 2-3 hour period so this is an indication of a leak but not enough to cause this amout of smoke. it also smells like gas as well but I am thinking since the carb wasover filled with gas it got the cats fuel soaked and that would cause my smoke issue any input would be greatful thanks.

GB7

iTrader: (1)

big fluffy cloud of white smoke = coolant seals most likely . If it stops once it's warm you might get by for a while [i had one that did that for over a year before pulled for a rebuild, however not recommended ]
as far as gas smell =IT'S A ROTARY
you should look for any leaks around carb or fuel lines,intake ect but the exhaust is always going to smell a little rich

dabranco

iTrader: (3)

I know a couple outside seals on the carb have a small leak and the floats do not hold fuel, was qouted as a rebuilt carb but I doubt it, the car sat for at least a few years in a barn.

So since it could be the coolant seals I take it just do a rebuild on it (depending on how the housings are) I may just get a remanned engine though.

Kentetsu

Before you decide to tear it down, run a search on "alumaseal". Saved me a rebuild...






.

RustyRacer

Does it do it when you first start up in the cold? It could be a leak, but it could also be the moisture in the fuel and exhaust being heated.

misterstyx69

iTrader: (142)

Compression test the engine before you spend all that money.
Why is Rebuild the only answer?..(unless it is Steve Austin we are talkin about ..then Ya.)

dabranco

iTrader: (3)

I am planning to thanks Ken I will try this
It does it when you first start it and gets worse the longer it runs. The cloud gets poofier and bigger
I am also planning on this before a tear down but my only concern is that I will do more damage then good letting it warm up. If the housings are good and rotors are good why risk the damage? Like I said it will be done since I have found out how to do a compression test with a normal compression tester.

Thanks for the ideas guys, I should be home around weds.

RustyRacer

Could be your intake manifold gasket, mine had a small tear in it when I first got it.

85rotarypower

Sounds like a coolant leak somewhere that is letting coolant into the engine. There are 2 possible causes for this. The first is a bad intake manifold gasket. The intake manifold on the 1st gen RX-7 is a "wet" type, meaning it has coolant in it. This is the first place I would check. There are 2 ports for the coolant to flow through on the intake manifold and a bad gasket here could leak coolant into the engine.

The second one is harder to deal with and relates more toward an overheating problem in the engines past. Due to the construction of the engine, being more or less like a sandwich, when the engine overheats the plates can warp. This generates small gaps between the plates that will leak coolant into the engine internals. To my knowledge, it is kinda random where these leaks can occur and a compression test may not show the leak. The bad part about this type of leak is that it isn't easily fixed if conventional stop leak additives don't work. It requires a complete tear down and close inspection of all the parts. If your lucky, any warpage can be taken care of with a mild lapping (to flatten the surfaces). If your unlucky, major parts will need replacing.

My advice, try some stop leak additives in the coolant first. Kentetsu mentioned alumaseal which I have heard works well. If that doesn't help, replace your intake manifold gasket and coolant passage o-rings. If that doesn't solve it, a rebuild or reman engine may be needed.

KansasCityREPU

iTrader: (9)

Check to see if the overflow is being presurized. Just pull the hose out and see if there is air coming out. If it is, there is an internal water seal leak where the combustion is pressurizing the cooling system. It will also cause steam (smoke) out the exhaust. If not then pull the intake/carb off and check the water seals in the intake.

Kentetsu

13Bs usually blow coolant seals in a manner which allows combustion gases to enter into the coolant system. This pressurizes the system, and makes it impossible for an addative to work.

12As usually blow in a manner which allows the coolant to escape into the combustion system, and then out the tail pipe. Because the direction the coolant is flowing in is now going the correct direction, an addative will work.

I haven't updated my figures lately, but last year we were like 85% success rate on 12As and about 20% on 13Bs.

When I installed my (bad) motor, it was fine until the thermostat opened. Then it was like the apocolypse! Had to shut it down because nobody could even drive down my road due to the visibility issue. After a lot of research I chose the Alumaseal, poured it in, and an hour later I was on the road symptom free. That was 3 years/30,000 miles ago. You can call me a firm believer.

dabranco

iTrader: (3)

I am very thankful for all the info of this site. I did look but when answers are anything from coolant seals to bad apex seals it makes it hard to narrow down. I will let you guys in on the info about my rx7, it is a 1984 12A 110,000 miles (from what I come to understand barely broke in) everything pretty much works, the car is from IOWA originally (i have orig. title). It is pretty clean as far as rust (will deal with that at a later time). I was told the carb was rebuilt but it doesn't look like it was ever removed (so a rebuild is needed there). It has sat for 6 years in a barn in Iowa before the guy I bought it off of got it. It does need work but not as bad as my 95 bronco...... heck the wifes 78 bronco needs less work done to it.

dabranco

iTrader: (3)

Well performed a compression test and here is the numbers. Front housing 65-70 PSI rear 60-65 PSI. This is using a cheap compression tester. The white smoke goes away once the engine is fully warmed up (all gauges work and are accurate but the fuel gauge). Carb needs a rebuild float hold no gas.

RustyRacer

Don't mess with the float settings. Check to make sure they don't leak but don't adjust them.

Sounds like its wearing nicely, mine is 48-52 PSI with 165k on it. If you're going to rebuild the carb, might as well take it all the way down to the engine and check your intake manifold gasket. Though Kentetsu offers a good way to possibly stop this, you could check and replace the gaskets.

Kentetsu

"One of the bowls will not hold fuel"

Is fuel getting into that float bowl at all? Or is it getting in, then running straight out?

Since the car sat for so long, the float needle could be stuck which would prevent fuel from getting into the bowl at all. Banging on the top of the carb might shake it loose.

dabranco

iTrader: (3)

Well I found a few vac leaks as well, AIR stuff so I am going to do a ratsness removal rebuild the carb as I found a couple of small gasket leaks. The car stays running and will run once it is warmed up just need to fix a few other issues as well.

Bertio

Gas smell is usually always from Carbs. You have gas just floating in the bowls. Make sure your cabin is sealed up tight.

dabranco

iTrader: (3)

Figure I would update this thread, so far the car is running smootherish, idle is high awaiting new header and savign for an intake setup. Coolant leak is ultra slow 1 PSI in a 24-48 hour period. I am also waiting for a new clutch kit as mine appears to be one its last legs.