CARBURETOR DATED

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,869
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Just a random thought but has anyone considered a drain-back issue?
I have drain back issues but i think mine are due to the diaphram on the fuel pump, the fuel lines are empty after a couple days. I put a fuel line check valve before my fuel nipple in the hose honestly no idea if its doing much or not but i thought it seemed to hold better

Cranking first, then a couple pumps, itll start everytime
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,464
Reaction score
8,737
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
wdym not possible?
Fuel comes in from the top,not the bottom it can't pull a siphon because it will suck air from the top of the float bowl.
 
Last edited:

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,464
Reaction score
8,737
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
I have drain back issues but i think mine are due to the diaphram on the fuel pump, the fuel lines are empty after a couple days. I put a fuel line check valve before my fuel nipple in the hose honestly no idea if its doing much or not but i thought it seemed to hold better

Cranking first, then a couple pumps, itll start everytime
The valves in the fuel pump should keep fuel in the main line. If you are running a 1406 and a 3 line pump it will probably never hold fuel long from the pump to the carb. It will drain through the return line as if there is the tiniest air leak,porosity of the fuel line,as soon as enough fuel evaporates to et the seat open a tiny amount, or if the needle and seat leak at all.With the 1406 and a return line the only thing keeping fuel in the feed line from draining through the return line is that it can't get any air, just like putting your finger on the end of a straw to hold liquid. Any air at all and your liquid runs out.Qjets with a return style pump had the needle and seat and a check valve in the fuel filter to keep fuel in the feed line. But your 1406 bowl should hold fuel to start the vehicle because the fuel bowl can't syphon.
 

boloboss

Full Access Member
Joined
May 6, 2023
Posts
72
Reaction score
19
Location
Houston Texas
First Name
Shuntel
Truck Year
1984
Truck Model
Chevy C10
Engine Size
v8 350 5.7 liz6er
...What is drain back issue?????
 

3 Ton

Junior Member
Joined
Oct 14, 2024
Posts
23
Reaction score
61
Location
Pacific Northwet
First Name
Fred
Truck Year
1978-79 78 body, 79 gearing
Truck Model
K-15 Suburban
Engine Size
350
AFB Carter has a working one way check valve in it. They work.
Ive gone thru a few brass check valves, they last about a year.
When working I have no leak off for a week. Now over the weekend.
 

boloboss

Full Access Member
Joined
May 6, 2023
Posts
72
Reaction score
19
Location
Houston Texas
First Name
Shuntel
Truck Year
1984
Truck Model
Chevy C10
Engine Size
v8 350 5.7 liz6er
@Ricko1966 thx man!
After 15 minutes of sitting. I noticed all the fuel has left the inline filter and the primary fuel filter. Any reason why.... or do you think it's vapor lock, fuel boil, carburetor getting too hot ,and maybe I need to block the heat shield on the intake, and also put a heat soap gasket under my carburetor????
 

MikeB

Full Access Member
Joined
Apr 4, 2014
Posts
1,775
Reaction score
1,005
Location
North Texas
First Name
Mike
Truck Year
1969
Truck Model
C10
Engine Size
355
About drain back: So you're saying there is a enough vacuum in the line to pull fuel up from the float bowl past the needle & seat? Wouldn't a vacuum in the line pull the needle even tighter up against the seat? On the other hand, I can see how heated fuel with 10% ethanol, just sitting in place, can evaporate out of the bowl vent ports.
 

boloboss

Full Access Member
Joined
May 6, 2023
Posts
72
Reaction score
19
Location
Houston Texas
First Name
Shuntel
Truck Year
1984
Truck Model
Chevy C10
Engine Size
v8 350 5.7 liz6er
What is this bracket called that the acceleration cable runs through
 

Attachments

  • PXL_20241105_181703627.jpg
    PXL_20241105_181703627.jpg
    157.2 KB · Views: 16

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,464
Reaction score
8,737
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
@Ricko1966 thx man!
After 15 minutes of sitting. I noticed all the fuel has left the inline filter and the primary fuel filter. Any reason why.... or do you think it's vapor lock, fuel boil, carburetor getting too hot ,and maybe I need to block the heat shield on the intake, and also put a heat soap gasket under my carburetor????
Do you have a 3 line fuel pump? I would assume so. Read a couple of posts back it's covered if it's 2 line you need a new fuel pump
 

boloboss

Full Access Member
Joined
May 6, 2023
Posts
72
Reaction score
19
Location
Houston Texas
First Name
Shuntel
Truck Year
1984
Truck Model
Chevy C10
Engine Size
v8 350 5.7 liz6er
@Ricko1966 so what is the issues with the two-line fuel pumps? So are you saying just get another two line fuel, And what's the best kind that you recommend to buy?
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,464
Reaction score
8,737
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
@Ricko1966 so what is the issues with the two-line fuel pumps? So are you saying just get another two line fuel, And what's the best kind that you recommend to buy?
Do you have a 2 line or a 3 line.?
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,464
Reaction score
8,737
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
If it's not holding fuel in the fuel line between the fuel pump and carbureator,I'd get a new fuel pump. But I can't recommend one because 99 percent of them now are junk,it's trial and error to get a good pump now. I hate to say this,but I'd call Facett, they make American made,ethanol resistant electric pumps. Their tech guy is good. I think they have a Posi Flo pump that will lift fuel 5 feet and is valved to prevent fuel from draining back. They don't sell to General Public,they will recommend you to Pegasus Racing to buy a pump. Their tech guy sucks,so don't talk to him. Get your recommendation from Facett,Measure distance from tank to existing fuel pump location.See what he says about putting a Posi Flo pump at that distance. If he says yep.Order it from Pegasus using Facetts recommendation. Then I'd mount it in the stock location with the lines you have and I'll give you wiring instructions. There is no other pump I'd recommend this with,most pumps are engineered to mounted close to the tank and below fuel level.I'm not certain I'd do this with the bad boy Facett pump. Ask the Facett tech guy. Now to complicate things further Facett it is just one brand of pump made by a different manufacturer,so you will need to Google who makes Facett fuel pumps and then look up the number for that company. Right here in the states with a tech guy that speaks fluent, English.If he says no,then we will regroup and come up with a plan.
 
Last edited:

Latest posts

Forum statistics

Threads
44,186
Posts
951,108
Members
36,310
Latest member
BLAKMAX
Top