l18 engine stalling

[realdiehl]

i recently purchased a 1970 datsun 510 that was not running. i installed a new weber 32/36 carburator,flushed out the gas tank,new fuel lines,new fuel filter,fairly new fuel pump. i was able to get the car to start and run fairly smoothly but after about a minute in stalls and will not start back up until it sits about 10-15 minutes and then it will start back up and run again for another minute and then stall out again.i noticed that as it was trying to stall out if i put my hand over the carb and shut off the air supply it would try and stay running briefly before stalling. i also noticed extreme amounts of suction when i placed my hand over carb and not sure if that means anything or not.any help would be appreciated as this is me and my sons first project car so were trying to learn as we go.

[datzenmike]

Sounds like it might be flooding. Look down the carb while idling... can you see gas dripping or running down inside. The float may be set too high and the carb is overfilling.

[realdiehl]

No i dont see any gas down the carb while idling. Do you think it possible that the fuel pump is pumping to much fuel. Weber said in the manual to have a maximum of 3.5 psi fuel pressure and i believe the fuel pump puts out 3.5-4.5 psi

[datzenmike]

.i noticed that as it was trying to stall out if i put my hand over the carb and shut off the air supply it would try and stay running briefly before stalling.

 

I guess I missed this. It would indicate maybe running out of fuel. Well next time it quits, remove the top off the carb and see where the fuel level is. (the stock carb has a sight glass so you can see in) The weber doesn't and it would be nice to know if over full or empty.

[banzai510(hainz)]

It would indicate maybe running out of fuel.

 

MIke if its out of fuel you just cycle the linkage a few times to see if the accell pump is squirting gas in the main barrel. IF NO GAS squirting then you can assume the bowl is dry and not take the carb apart.

 

 

realdiehl;

No i dont see any gas down the carb while idling.

 

YOU WONT !!!!. THERES A IDLE JET CIRCUT. the brasss screw with the spring at the base of the carb. thats the idle adjustment. If wrong car wont idle.

[realdiehl]

If i cycle the linkage i do see gas squirting in the main barrel. Adjusting the air/fuel idle jet did not help it as far as it stalling out. Also it doesnt make a difference if it is idling or i keep the rpms up it will still stall out after about a minute. I also have a clear fuel filter and at the top of the filter i can see the gas swirling around.

[banzai510(hainz)]

soon as it stalls out cyle the linkage and see if gas in there. If Yes.

then go to the coil and feel if you think its HOT!!!!!!!!!!!!

Maybe your running a point coil with out a ballast resisitor.???????

 

 

when you think its going to die try taping on the carb right where the fuel hose goes in the carb body. there is a little needle valve that may get sticky and not let gas in. But i dont think its it as you said the accell pump works. Sometimes this valve can stay open to long and the float isnt engaging the needle valve right and let to much gas in thus flooding it out.

Youll have to look at the plugs. Sometimes if you rn the motor fast enough it will use more gas than needed and be Ok till you idle to much gas will go in thus FLOOD out. but youll be able to tell looking at the spark plugs

 

why dont you take photos of everything and post to see what you got.

 

take photo of fuel pump and distributor and coil area.carb ect......

[realdiehl]

I will try that and see what happens. My digital camera broke and all i have is my phone and i havent been able to figure out how to post pictures yet

[realdiehl]

Ok i was able to work on the car a little bit today. I was able to get the car to idle. While idling i checked the coil and it was hot. I ten went to put on the air cleaner and the car quite running. I then checked the accel pump and it squirted a strong stream into the main bowl. I wad able to get it started up again and adjusted the idle mixture screw out one turn and it started idling better but still not as good as with the air cleaner off. I was able to give it some throttle but as soon as i gave it alot it stumbled and died again. So now im not really sure what to do next. . . .

[realdiehl]

[datzenmike]

 

That matchbox is awfully close to the exhaust. Clocking the dizzy 90 degrees would put it in the air from the fan.

 

Maybe wrap the matchbox with some pink insulation and see if the problem goes away.

[realdiehl]

Ive heard people say that its hard to get the distributer back in. Is that what i need to do is pull it out and rotate it 90 degress. Will it mess up my timing or anything like that. Can you tell me the exact process to do that. Thank you for helping me try and dial this thing in

[datsunaholic]

You can't rotate it 90 degrees- they don't have enough adjustment. You can rotate it 180 degrees by unbolting the pedestal and bolting it down the other way. You will have to rearrange the plug wires though.

[datzenmike]

I was thinking dropping the spindle and turning it 90. The rotor would have to turn 90 to match it and drop in... then swap the plug wires one position clockwise.

[datsunaholic]

The problem, Mike, is the matchbox itself can't clock 90 degrees All moving the spindle does is moves the rotor, not the body. Turn the rotor 90 degrees, and change the wires, but the module STILL faces right at the manifold. It's limited by the 2-bolt base and the adjusting plates. You only have 2 positions, each with ~ 30 degrees or less of swing.

 

To fix it, you need different adjuster plate with the clamp groove 90 degrees clockwise of where it is... or basically the original setup. You get that rear-facing Matchbox by using a points base and adjustment plate. Or by having the adjuster plate upside-down, I've seen that too. Makes timing it hell though.

[datzenmike]

Yup.... Should have remembered this on my 710s. The vacuum advance can swings around and hit this emissions thermal switch in the thermostat housing. Had to remove it to get the timing set.

[realdiehl]

Well im really confused now. What is the approach i need to take to alleviate the matchbox pointing at the exhaust manifold

[realdiehl]

This is a close up of the base of distributer.

[datzenmike]

Even a small sheet metal heat shield will help. Try some aluminum foil first and see if the problem is heat.

[banzai510(hainz)]

spend 10$ and get a shorter + side batter cable.

 

clean up the wires to the distributor

I would make red wire to B

blk wire to C

 

whats that funky blu wire.??????????

 

that ground battery wire can also be shorten right to the head by the fuel pump. NO like what you go it thats hoky!!!!!! shorter cable will clesan this up nicely.

 

I seen macthboxes run as you have them in your photo here in washington and most were OK. I really dont know if the heat kills them but in texas man those might get HOT.

[datzenmike]

Heat usually makes most electronics act up but when they cool down that start working again. Most if not all matchboxes are facing the rad or turned so that the rad air blows on them.

[realdiehl]

The car is still stalling after about a minute of running. I pulled the top of the carburetor to look at the float and this is what i found. Is this a float level issue or is this a fuel pump issue.

[datsunaholic]

Could be either. Fuel pump is easy to check. Crank and see if fuel comes out. Could be a clogged filter too. Or lines.

[realdiehl]

I tried that and fuel came out of pump. How much fuel should come out. It didnt come gushing out or anything but it was a steady stream.

[banzai510(hainz)]

When I take the out put side of the fuel hose, Usaully the end where it hooks up to the carb

I will take it to more the passenger side and point in a sfae direction and when you startt the car the carb should be shooting out alot of gas.

 

But this would have been ez to figure out with out taking the carb off as the accell pump would not be working right now either.

 

I would have ck the output of the fuel pump right when it died.

Then see if iy shoot gas out. then hook it back up and then cycle the linakge to the carb and see if gas shoots in carb If not then. I would pour a little gas in the carb and see if it runs. if yes then I know its not a electrical system.

 

I know would pull the carb top off like you did or better yet right where the gas line goes in try tapping on there and maybe the needle valve is sticky and not letting gas in.

 

 

 

As for the steady stream statement. The pump sucks gas in then come out when you push on the pump. So it should pulsate soemwhat. Maybe not enough pressure to push the needle valve open but at idle a L motor doesnt need much gas.

 

PS the fuel pump should have like a 1/4 is less spacer between the head and the fuel pump. If not the arm can/will get bent.

 

 

then after all this fix those battery cables