truck wont stay running

[katfish]

good day wise ones  This is about my truck wont stay running just changed out carburetor, now it wont run unless igive it squirts of fuel  it seems its not getting to the bowl but the fuel line on the carburetor says its good  is it sucking air from somewhere? got me miffed appreciate your help (1971 521 )

[gene knight]

check to see if nuts that hold onto manifold are tight, does it have a spacer under carb?  is it a hitachi carb? if so  change it out for a weber 32/36

[datzenmike]

22 hours ago, katfish said:

good day wise ones  This is about my truck wont stay running just changed out carburetor, now it wont run unless igive it squirts of fuel  it seems its not getting to the bowl but the fuel line on the carburetor says its good  is it sucking air from somewhere? got me miffed appreciate your help (1971 521 )

 

 

 

What is the 'new' carburetor from? Does it have an idle cut solenoid? It's the hex shaped thing with the red wire.

 

[banzai510(hainz)]

if it only runs when pumping the gas that means the idle jet is plugged

 

more info is needed

put the choke ON. or make it come on by pulling the electrical wire if elelctric choke.  then see if runs better as the choke will enrich the circut and by pass the idle mixture.

 

soeme carbs have a idle cut off. which needs 12volts to let gas in the idle circut so best to have a close up photos and type of carb.

 

this is a simple fix

 

also it could be a loose carb to manifold creating a airleak at idle.  soem times over tighten the cheap carb adapters can crack those giving a airleak.

[katfish]

thanks im not sure about what a idle cut solenoid is  it has a manuel choke no wires on this carb it wont stay running with the gas pedal just me squirting fuel in the bowl  carb is snug to manifold  ill look for the name of the carb maXpeeding RODS is the name of the carb. didnt have an adapter just a gasket for the manifold 

[datzenmike]

You said you replaced it so thought it might have one if from a later vehicle.

 

On 4/7/2022 at 1:50 PM, katfish said:

good day wise ones  This is about my truck wont stay running just changed out carburetor, now it wont run unless igive it squirts of fuel  it seems its not getting to the bowl but the fuel line on the carburetor says its good  is it sucking air from somewhere? got me miffed appreciate your help (1971 521 )

 

1 hour ago, katfish said:

thanks im not sure about what a idle cut solenoid is  it has a manuel choke no wires on this carb it wont stay running with the gas pedal just me squirting fuel in the bowl  carb is snug to manifold  ill look for the name of the carb maXpeeding RODS is the name of the carb. didnt have an adapter just a gasket for the manifold 

 

A lot of unknowns with an after market carburetor. Can you post 4 or 5 pictures of it?

[katfish]

wow i have a new found respect not just for your  knowledge but anyone who can post pictures  on here  it had my daughter scratching her head sorry for some of the angles but just consider the source  anyway thanks for all the  help 

 

 

 

[Stoffregen Motorsports]

First off, that linkage aint gonna cut it. The right angle in the cable needs to be made into a straight line.

 

Second, it LOOKS like a stock carb, but obviously new. So that leaves two options, either A - a good quality reman or B - a cheap Chinese knockoff. Now I'm not someone who thinks all Chinese parts are garbage, but certainly a good amount of things that come from China or India, Pakistan, Taiwan, etc are immediately suspect.

 

You said it can run, but not at idle? Is that right? Does it run when you open the throttle? Or do you need to feed it fuel from a can? If it runs past idle, it's likely an adjustment, or maybe a vacuum leak. Have you tried adjusting the idle screw? There should also be an idle mixture screw that can take some adjustment. Generally about two turns out. I always give it another half turn out to compensate for the building heat when the hood is closed.

 

Was there anything else you changed around the same time? Ignition timing out of whack can do the same thing - not idle but run above idle.

Edited April 9, 2022 by Stoffregen Motorsports

[Stoffregen Motorsports]

I just noticed that big hose, the braided one coming off the manifold. Is that the PCV hose? If so, there's your vacuum leak.

[banzai510(hainz)]

36 minutes ago, Stoffregen Motorsports said:

Have you tried adjusting the idle screw? There should also be an idle mixture screw that can take some adjustment. Generally about two turns out.

what Stoff Motorsport says.

[NC85ST]

On 4/7/2022 at 4:50 PM, katfish said:

it seems its not getting to the bowl

So there is no fuel in the float bowl? If you don’t see fuel through the large sight glass, start working your way back to the fuel pump. It could be that the float is not adjusted correctly or there is a problem with the needle and seat or fuel inlet has an issue. All of this is based on the above statement.

[katfish]

thanks for all the reply's no fuel in the bowl, sight glass has fuel up to the fuel line, the braided hose is for the pvc that attaches to the bottom of breather the carburetor is from china  the linkage gave me fits i wanted it in a straight line but that was the only way to make it fit i have not adjusted any of the fuel or mixture screws So ill put the breather back on ,hook up  the pvc hose adjust the two screws on carburetor  its like the diaphragm is not priming the bowl. if not then ill check the float and the needle and seat,  to be continued  thanks for all the good info ill keep everyone posted  

[datzenmike]

On 4/9/2022 at 1:59 PM, Stoffregen Motorsports said:

I just noticed that big hose, the braided one coming off the manifold. Is that the PCV hose? If so, there's your vacuum leak.

 

 

The hose with the loop is the block vent to the PCV valve. The big braided one with the two hose clamps I can't see where they go. Katfish?????

 

 

 

All Chinese knock off carbs have LEVEL across the glass. Nissan just used a line so it works with any language.

[NC85ST]

So it’s not shooting fuel down the throat of the carburetor? Accelerator pump is bad or trash in the jet. As for the throttle cable, if you still have the original carburetor, take the throttle piece’s off of it and use them on the new carburetor. You can try swapping the accelerator pump as well. Why did you change the carburetor to begin with?

[datzenmike]

 

See if you can move that clip that holds the end of the throttle cable back to the bolt that holds the manual choke. That would get rid of some of the severe bend.

[katfish]

roger that on moving the clip on the throttle cable back where the manual choke is  my father in law had a electric carb on it with no wires hooked up i changed it out because it was doing the same thing as the new carb  so i thought the accelerator pump was bad because it wouldnt stay running  it was running until i removed the smog pump and blocked holes on manifold. appreciate your help and ideas !