The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 12-14-2021, 06:55 PM   #1
ellisjay2
Registered User
 
Join Date: Feb 2014
Location: marietta ga
Posts: 147
Carburetor runs on choke and no fuel squirting at nozzles

Have been having this problem I think of fuel starvation. On a cold start full choke engine will hit and run, until it begins to warm up and with manual choke, once I move choke open will die.Will idle at half choke. I also noticed fuel isn't squirting out nozzles in carb. Have a clear filter before carb half full of fuel, pressure gauge also showing 6psi of pressure. The carb is a Holley 4150 double pumper. Before this I had a flooding issue in both secondary and primary as fuel flooded out air vents, I replaced both needle and seats and flooding problem ceased. I adjusted both floats to where fuel is seen just below sight plugs as you shake engine and get trickle of flow....if I raise primary float anymore, flooding out air primary vent reoccurs. When opening air throttle it starves immediately. It sounds as if I need to pull carb and do some cleaning and break off fuel bowls...clean out venturies...

....This just started recently....sounds as if trash or so is getting involved..clear filter does show brownish particles...
Attached Images
   
__________________
: Eli540

86 gmc 2500 longbed Carb 5.7, rwd,
400 tranny.

Last edited by ellisjay2; 12-14-2021 at 07:10 PM.
ellisjay2 is offline   Reply With Quote
Old 12-15-2021, 12:20 PM   #2
truckin 79
Registered User
 
Join Date: Jun 2014
Location: CO
Posts: 749
Re: Carburetor runs on choke and no fuel squirting at nozzles

I am not claiming to be an expert here on carbs but have had experience with holleys. I had a nova 350 holley dp with manual choke and it was finicky on cold starts. I would get rid of the glass filter and go with some universal filter with paper element. Do you still have the original holley filters in the inlet bowls? I usually got rid of those as well once I put on a universal filter like below NAPA In-Line Fuel Filter (Auxiliary Replacement)
Part # 070FL33617. I feel those glass filters let a lot of crap through plus they can leak and we know what that could lead to. I think you are right carb might need to be rebuilt. What you could try though is pour some fuel/carb cleaner in primary and secondary vent tubes. If you are not getting fuel out of squinters then something is clogged. There is a phillips head screw that hold squinters down you can unscrew and see if some dirt/debris is present. I would start with getting rid of that glass filter though
__________________
79 Chevy 2wd BIG10 350 TH400
truckin 79 is offline   Reply With Quote
Old 12-15-2021, 03:24 PM   #3
ellisjay2
Registered User
 
Join Date: Feb 2014
Location: marietta ga
Posts: 147
Re: Carburetor runs on choke and no fuel squirting at nozzles

Yeah glass filter was what I used for time being after dropping motor in...truck is not drivable yet....not sure about filters in carb, but will pull nozzles, bowls and go from there....I'm thinking trash from tank got in some how....thank for feed back...
__________________
: Eli540

86 gmc 2500 longbed Carb 5.7, rwd,
400 tranny.
ellisjay2 is offline   Reply With Quote
Old 12-15-2021, 10:17 PM   #4
Pontiac1976
Registered User
 
Pontiac1976's Avatar
 
Join Date: Oct 2015
Location: Ottawa, Ontario, Canada
Posts: 766
Re: Carburetor runs on choke and no fuel squirting at nozzles

Hello. If your talking squitter's nozzles at the top under the choke flaps then they only squirt peddle movement. Now as said if your having dirt in the gas. I would take to carb off remove the bowls blow out the carb with carb clean. Is this a new carb or is it a used carb you got for your motor. It sound like you may have the floats set right now but if dirt in the gas bowls you may have to re set the floats again.
I would try to see what jets sizes are in the jet plates 68,70,72,74,76,78, front and back should be two of the same size IE: 68's FRT. 72's REAR. and I would set the carb to the basic set screws 2-1/2 turns out or close to that till you get it running ok then a big Vacuum Gauge is the best after to help set the carb.

Ok now the glass fuel filter I ran one for 2-1/2 year back in 1984-on my car I drove every day raced at the drag stripe. BUT the Best place for the glass or the Fram G3 Plastic see throw, is down by the frame by the fuel pump where cooler air is on it at all times put in inline to the in side of the fuel pump! I changed out to a FRAM G3 clear see throw filter 1986 much lighter easier to see when to change been using them ever motor now by the way it think it 3/8" fittings stock line 5/16".
__________________
1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed
Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change.
Pontiac1976 is offline   Reply With Quote
Old 12-17-2021, 02:23 AM   #5
ellisjay2
Registered User
 
Join Date: Feb 2014
Location: marietta ga
Posts: 147
Re: Carburetor runs on choke and no fuel squirting at nozzles

This is a temporary use of steel fuel line I had to bend to fit connection to Holley, if I switch to Edelbrock, will use different line. Once again truck is not being driven at this point.

Carb is used not brand new.
Attached Images
  
__________________
: Eli540

86 gmc 2500 longbed Carb 5.7, rwd,
400 tranny.
ellisjay2 is offline   Reply With Quote
Old 12-17-2021, 11:05 AM   #6
Rickysnickers
Senior Member

 
Join Date: Oct 2014
Location: Eagle, ID
Posts: 3,063
Re: Carburetor runs on choke and no fuel squirting at nozzles

Flipped your photos
Attached Images
  
Rickysnickers is offline   Reply With Quote
Old 12-18-2021, 03:35 PM   #7
Pontiac1976
Registered User
 
Pontiac1976's Avatar
 
Join Date: Oct 2015
Location: Ottawa, Ontario, Canada
Posts: 766
Re: Carburetor runs on choke and no fuel squirting at nozzles

From what I can see of the pic now. You do not have a double pumper unless you have two Accelerator Pumps on the carb. So you only basic 4150 front set screws and most likely no rear jet plate for jets unless some one add it.
So if no work part up grades to the carb the jets should be between 66-68 in the front. The Holley gasket if pretty new or been upgraded to re-usable one can be reused un less the rip or tear get gas soaked. So I would at less the front bowl off clean bowl and the main body with carb clean wear safety glass and the fuel filter too. Check adjust make sure clean put back together do not over tighten the screws the carb body is alloy,
just tighten to specks or lightly com pressed just so it does not leak. If you over tighten gaskets flatten out to soon start to leak soon then you can not snug the gaskets up later with out it leaking(need new gasket sooner). Once the carb is clean and the fuel filter start set screws as said if your timing pretty good it should start, then adjust get it smoother. Then fine tune with a big Vacuum Gauge.

Oh I forgot to tell you double check the power valve make sure it not blown or ripped on the back side of the front bowl the main jet plate. You may need a gasket renew kit the Holley card 4150.
__________________
1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed
Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change.

Last edited by Pontiac1976; 12-18-2021 at 04:07 PM.
Pontiac1976 is offline   Reply With Quote
Old 12-19-2021, 02:16 AM   #8
ellisjay2
Registered User
 
Join Date: Feb 2014
Location: marietta ga
Posts: 147
Re: Carburetor runs on choke and no fuel squirting at nozzles

Quote:
Originally Posted by Pontiac1976 View Post
From what I can see of the pic now. You do not have a double pumper unless you have two Accelerator Pumps on the carb. So you only basic 4150 front set screws and most likely no rear jet plate for jets unless some one add it.
So if no work part up grades to the carb the jets should be between 66-68 in the front. The Holley gasket if pretty new or been upgraded to re-usable one can be reused un less the rip or tear get gas soaked. So I would at less the front bowl off clean bowl and the main body with carb clean wear safety glass and the fuel filter too. Check adjust make sure clean put back together do not over tighten the screws the carb body is alloy,
just tighten to specks or lightly com pressed just so it does not leak. If you over tighten gaskets flatten out to soon start to leak soon then you can not snug the gaskets up later with out it leaking(need new gasket sooner). Once the carb is clean and the fuel filter start set screws as said if your timing pretty good it should start, then adjust get it smoother. Then fine tune with a big Vacuum Gauge.

Oh I forgot to tell you double check the power valve make sure it not blown or ripped on the back side of the front bowl the main jet plate. You may need a gasket renew kit the Holley card 4150.
It's a double pumper bro...I just didn't show other pump on secondary side...I'm taking both bowls off now and doing clean...repair...
Attached Images
  
__________________
: Eli540

86 gmc 2500 longbed Carb 5.7, rwd,
400 tranny.
ellisjay2 is offline   Reply With Quote
Old 12-19-2021, 03:23 AM   #9
ellisjay2
Registered User
 
Join Date: Feb 2014
Location: marietta ga
Posts: 147
Re: Carburetor runs on choke and no fuel squirting at nozzles

Status of carburetor starve for fuel...Holley 4150 double pumper...

So far have taken off carb bowls and looks typical I'm guessing, but has me wondering how this thing even ran to be as dirty... nozzle sprayers read .028


Primary metering block and bowl....
Attached Images
     
__________________
: Eli540

86 gmc 2500 longbed Carb 5.7, rwd,
400 tranny.
ellisjay2 is offline   Reply With Quote
Old 12-19-2021, 03:43 PM   #10
Pontiac1976
Registered User
 
Pontiac1976's Avatar
 
Join Date: Oct 2015
Location: Ottawa, Ontario, Canada
Posts: 766
Re: Carburetor runs on choke and no fuel squirting at nozzles

WowI never seen one that dirty bowl side plate. AED or Mr. Gasket kit for Holley has good prices some time on Gasket re-new kits your going to need it looks like all the gaskets way bad carb dunk cleaner. It's gone have to be soaked a few times. (shop around carb kit supplier's)
I would double check the floats to make sure they not leaking holding any gas in it that will mess up your fuel bowl level setting.
__________________
1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed
Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change.

Last edited by Pontiac1976; 12-19-2021 at 03:50 PM.
Pontiac1976 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:51 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com