Axel121176

I have just inherited a 1979 RX7 when I got it it had sever blockage in the fuel lines an they were all replaced. While waiting for a new gas tank we tried running the car off of a small canister of gas and the car started up fine and ran good. About one week later the new tank and lines were installed and the connections were made and the vehicle would not start. I disconnected the fuel line from the carburetor and then ran the pump and fuel was coming out just fine however when the lines are connected to the carburetor the fuel goes in the carburetor and right back out the return line with no fuel visible in the sight glass or anywhere else in the carburetor. I now a pretty decent amount about cars and how to fix them but I have never had a car with a carburetor. Help would be greatly appreciated.

mperformance

U got to take the carb apart...but it's not that difficult. For this problem you need not remove the carb from the engine...just the top cover. Seems like the needle valve in the carb is stuck. You will need then to reajust the bowl floats and clean the carb also...

should be ok after that...

Robert99v6

I think that the problem is that your rex has seen much better days, and who ever had it before you jacked it all up

jrc240sx

Wonder who that was?

MosesX605

Could be that your floats are stuck closed. Take the airhorn off the carb and replace the needles and seats.

Rx7carl

Yea when you pull the top off the carb, dont be surprised if theres a bunch o' trash in the bowls. Sounds like it was run with crap in the lines/tank which have now made it into the carb.

Axel121176

Thanks everyone the car started but is pouring out smoke badly but it now puts out smoke really bad. The car sat for about 2 years and I think that oil may have leaked into the cumbustion chambers while it was sitting. However it is burning really rich and again I do not know much about carburetors and am unsure how to adjust it. (FYI) Thanks for the previous help the needles were jammed in the seats due to a thick buildup. Replaced the needles and seats and the car started easily.

MosesX605

There aren't too many adjustments on the Nikki. Basically the only mixture control you have is for the idle circuit. There are two screws on the drivers side of the carb, one controls the idle speed, the other the idle mixture. They are stacked on atop of another on the '79 carb, about in the middle of the driver side, on the throttle body. The large screw is idle speed, the smaller is idle mixture. Adjusting those may clear up any rough/rich idle problems, but if the car is running rich throughout the powerband, there is another problem to fix.

Now that you know that the car runs, I'd take the whole carb off and soak the sucker in solvent to clean off all the ****. Make sure not to soak any of the electrical attachments on the carb! Get a full rebuild kit and replace all the gaskets, the accelerator pump, and make sure the floats are dead on. When holding the airhorn upside down, the flat top of the float should sit nearly parallel with the airhorn, at a height of 16 mm (+-0.5mm) from the gasket to the float. When the airhorn is held right side up, the point on the bottom of the float should be 51mm (+-0.5mm) from the gasket to the float. Remember that the black plastic spacer plate has gaskets integrated into it, so don't worry about any carb to manifold gaskets unless they match all the vaccuum holes perfectly.

The smoke could be due to many things. It's only worth being concerned about if it doesn't go away. There was probably alot of **** floating around the carb that is now being burned up in the motor, not to mention any deposits in the motor itself. My car smoked something fierce when it ran rich (mixed up jets will do that to you ), so I imagine that your problem is probably not due to any internal problems. Actually my neighbour would have called the smog police if we had any up here in Saskatchewan, he was glaring at me the whole time. :P

While you're doing startup maintenance, get a cap and rotor, four new spark plugs, new plug wires etc from the Mazda dealership. Don't get the generic cap and rotor, as the don't last long enough to justify the savings IMHO. Get a new fuel filter, because all the crap going through the motor will end up in your filter. Also check your battery connections for corrosion, as bad connections at the battery can cause all sorts of havok.

Good luck with the car. I hope this '79 will have a good home, there aren't too many SA's left.