hard to start

[Datsun R Fun]

today i took the ol datsun 620 for a drive, after buddy rebuilt my carb, idle is lil high need to readjust that. but the most troubling thing to me was sitting at the light and it idled lower and lower till it died, and when i got it to start i had to pump like crazy till it fired, then from there hold throttle down petal to the metal and it sputtered but slowly reved up all this while it was not in gear(underload).

 

i am thinking there is something up with fuel delivery, i wanted to ask you what you all thought I should check? 

 

so far i am thinking possible issues are, clogged fuel line maybe in tank, maybe weak fuel pump, or perhaps accelerator pump diaphragm since the kit did not have one?

 

would love to put some more miles on my dato.

[LenRobertson]

 If it is the stock Hitachi, look in the window on the front of the carb and see if the fuel level is where it is supposed to be. It is sometimes hard to see it. If you bounce up and down on the fender, you can see the gas sloshing in there. If you can drive it around the block until it starts acting weird, shut it off and check the level again. If the fuel pump or filter or line is bad, the fuel level will drop way down. If the fuel level stays up, I'd suspect a plugged or loose jet or something like that. Also, check the choke and be sure it is opening all the way.

 

Len

[datzenmike]

This

[devilsbullet]

check plugs, plug wires, and coil. my 510 was doing this, I thought it was carb problems too. I ended up having a bad coil and bad plug wires, but I didn't figure that out until I had replaced the hitachi with a weber and it was still acting funny.

[Dawa]

before you buy anything, make sure you check every existing thing.

 

ensure the throttle cable isnt lose. 

 

get back us in regards to what carb youre running so we can better assist you. 

ive never had to mess with the hitachi but have had my fair share of problems

with the weber 32/36. 

[darrel]

It could also be running too rich and flooding out. Check one of the plugs when it dies.

 

Lots of things to check, just take it one at a time.

[Datsun R Fun]

the truck is a 1979 620 , iirc it does not have the lil window, but when i get outside during daylight will look it over.

[banzai510(hainz)]

does is squirt gas in the main barel when you cycle the linkage????? if no then the acell pump is bad. or the bowl is empty and the needle valve is not letting gas in the carb.

 

this is a simple fix.

 

Most Stock Hitachi carbs are a Mother F. to rebuild w/o screwing them up.

 

I would just get qa weber DGV 5 a man.  or a 38/38 weber

[Datsun R Fun]

looked at truck should the window on carb have fuel visible think seen lil at bottom?  took for drive yesterday when came to light and let idle it would just bout die if i did not rev it. the one time it died it started right back up. noticed some thing odd, when i ran the inductive timing light on each of the 4 wires all flashed constantly other then the cylinder nearest fire wall, this is odd cause i not too long back replaced the rotor bug, and cap, and wires made sure all connections where tight as best as i could with the wires on cap and plug ends.

 

some one suggested loose accelerator cable. is there adjuster or do i just take up slack at end attaching to carb ?

 

as there any good way to test coil ?

 

accel pump seems operational.

[banzai510(hainz)]

the cable usually goes thru a plate and the cable housing is usually threaded with a nut and you adjust it there.

 

cqrb should have the sight glass about 3/4 full.

 

when having idle proplem I ck for loose intake and carb bolts

Idle mixture setting

plugged idle jet.\

 

if stock carb thes are nearing 40 year old and maybe also be dirty.

clean fuel filter or opn the old one up to ck condition. Of how rusty the tank is

[LenRobertson]

Two types of float bowl windows - small round window with a white dot etched into the glass, or a large rectangular window with a white etched line in the glass. The fuel level should be pretty close to this level. "...think seen lil at bottom?" makes me think your level may be way too low. Sticky needle valve above the float, plugged fuel filter, weak fuel pump, partially blocked fuel line. There is (maybe) a fine mesh screen inside the banjo fitting on top of the float chamber, the fitting where the rubber fuel line hooks to the carb. I say maybe cause often these have been thrown away.  Float level can be adjusted by bending the tabs on the float, but it seems unlikely it would get out of adjustment. I would be absolutely sure everything else is good before trying to adjust this.

 

I have fixed a bad idle by removing the idle mixture screw at the base of the carb (count the turns out so you can get it back to about the same position), spraying carb cleaner in the hole, then compressed air. But I've done this on other carbs and it didn't help, but it is quick and easy to do.

 

Len

 

 

 

[Datsun R Fun]

had some one look at my truck , when they hooked up multimeter, ya could see alternator was charging at 16.8-18 v at times, and when the voltage spiked relays in the really pack would make bad noises, and the idle would drop and truck would die with out throttle. so they gave me alternator  to install so gonna do that tomorrow, and see if it changes the truck into decent running and idling truck well as dash light not be on and not worry bout blowing up battery.

.

 

on other hand appears this hitachi carb is hosed, so guess i will be saving for a weber dgev kit.

[Datsunrider71]

That's happening to me as well my car shuts off at the lights and the idel is mah low on my 510 too I try to mess with the Mix Screw and the idel screw and nothing it just revs high now smh.. 0_o

[Datsunrider71]

 

Stupid Hitachi crab

[datzenmike]

Is it warmed up because the choke is on (still)

[Datsunrider71]

I have to have it a lol open or it will turn off on me