Hitachi DCH 306 CARBURETOR PROBLEMS (1979 Datsun 210 A14)

[EdgarB310]

I have quite some time with this problem, the engine vibrates too besides emit a strong, foul smell raw gasoline (all this happens after the choke is fully open). This failure seems like a disconnected vacuum hose, plus a spark plug failure

My father and I e have disassembled and three times being only the first when I run in an "acceptable" we put new seals, nozzle and needle feed and still does not work properly (it acquired five years ago my B310 and I never caused these problems). loo and took it to a workshop and the result was worse. If you could help them greatly appreciate it!

 

-What e noticed is that the top of the carburetor is stained with what looks like a combination of gasoline and oil burning (in the photos not seen since a couple of days cleaning the carburetor to see if the fault would disappear)

-The fuel level is observed right through the small window is correct

-No vacuum hoses disconnected

-The spark plugs are new

-The spark plug wires are in good condition

-The distributor cap (electronic) is not cracked

 

 

 

 

 

 

 

[LeviGideon]

Check the base of the carb for leaks. Sometimes the mani or carb can get a little warped at the bottom and it won't get a good seal.

[LenRobertson]

Did you take the carb off the intake manifold and disassemble it completely? As LeviGideon said, the carb base gasket is one place for a vacuum leak. There are large screws holding the lower cast iron carb base to the upper carb body, with a gasket between. These screws can loosen up and cause problems. Sometimes you can grab the upper part of the carb and wiggle it if these screws get loose enough. Intake manifold to cylinder head gasket can fail. With the engine idling, spray carb cleaner around this gasket area and see if the engine sound changes (from carb cleaner being sucked in the leak). Vacuum hoses can crack at the ends where they push onto fittings. A few feet of new vacuum hose is pretty cheap, so worth just replacing all old hoses. The vacuum diaphragm on the distributor can rupture and cause a vacuum leak.

 

And the problem may not be a vacuum leak, but all those things are worth checking. You might watch the fuel level through the little window over a period of time at different engine speeds, to be sure there isn't a sticking float valve that only happens some of the time. Probably not, but possible. A jet or air bleed which has unscrewed inside the carb is another possibility. That is why I asked if the carb has been torn down completely.

 

I lust noticed in your pics you have all the original smog fittings. I think there are some vacuum servo thingies with diaphragms that could break and leak vacuum. Also the EGR valve - I can't remember exactly the symptoms of a sticky EGR valve, but I believe it can result in the engine running bad. Maybe do a search for EGR valve problems and see what it says.

 

Len