Hitachi Carb not pumping

[Cmac]

Looking for some assistance with a carb issue. I have the stock 1978 hitachi carb required to pass smog here in Ca. rebuilt with kit and now the issue is the cab does not pump fuel. I have fuel to the inlet of the carb and in the float bowl but have to use starter fluid or fuel dumped down the carb to get it started. Once the car has started and ran for a short time it will restart but if it sits for more that an hour or so it acts up again. Any Suggestions.

 

CM

[banzai510(hainz)]

is the accel pump working on the carb?

cycle the linkage and see if gas is being squirt in. If not then was the the ACELL PUMP DIAPHRAME INSTALLED wrong?

 

ALSO IS THE 12VOLT WIRE TO THE IDLE CUT OFF HOOKED BACK UP?

 

was this working before?

[RadioRedline]

so when you pump the gas the float does not fill up? how "apart" did you have the carb? 100%?

 

Radio

[Cmac]

I will check these items in a couple of hours. as for now all electrical is hooked up and when I move the linkage gas does not squirt out. As for the carb it was in a box of parts that came with the truck. 100% complete then 100% disassembled cleaned and put back together. Id have to say this was the worst carb I have ever had to rebuild ball bearings springs and crap all over the place. I wish I could just run the weber for smog and call it good.

[datzenmike]

Then it should work and was assembled incorrectly. The stock Hitachi is a great carb (when new or working) Yes it is complex but that's because it is designed for a specific application and has to be capable of meeting engine performance, economy and smog needs. The Weber is outside these requirements and can be made much simpler and performance oriented to fit a wide variety of engines. Most notice an improvement when swapping to a Weber but this is an unfair comparison as likely the reason for the swap is that the Hitachi is not functioning properly in the first place. It probably has 150-200K on it, plain worn out, has been rebuilt by home mechanics and parts left out or adjusted wrong, or swapped for another Hitachi not for that application. So yeah the Weber runs better. If you have a good running or well rebuilt Hitachi you wouldn't even think of getting a Weber, there would be no need. Yes they are simple and provide a margin of extra performance, but not economy. Webers can also be pretty picked over too so watch out for some piece of junk that was someone else's problem. If getting a Weber get a NEW direct replacement for your car with all linkages and adapter plate, proper hose connections and definitely an idle cut solenoid and electric choke heater. Looking at about $300 but saving $150 worth of headaches looking for missing linkage, gasket, adapter plate, air filter, wrong jets, worn out accelerator pump, stuck/non functioning choke.

 

 

The Hitachi? There are two ball bearings in the accelerator pump circuit that act as one way valves. One only allows gas in from the float chamber and prevents back flow on the pressure stroke of the pump. The other only lets gas out into the primary throttle bore and does not allow air to be sucked back in on the suction stroke of the pump.

[Cmac]

Turns out the accelerator pump was working took it out and ripped it putting it back in Argh. new one installed now. But on the back side of the float the spring / rod that attaches to the top plate of the carb was frozen. I freed it up and now the gas is pumping now and truck is running like a champ. Thanks for your help and suggestions.