Do I need an electric fuel pump!

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.

Barrett-FL

Junior Member
Joined
Nov 5, 2023
Posts
18
Reaction score
15
Location
Central Florida
First Name
Barrett
Truck Year
86
Truck Model
C10
Engine Size
350
I just purchased an 86 C10 with a 350 and it runs great and starts at the turn of the ignition…that is if I start it every day, however, if I let it sit for a couple days I have to crank and crank to get the fuel filter to fill up and get gas to the carb. Once the filter is full it will start perfectly but after a couple days of not being started the issue repeats.
Do I need to install and electric fuel pump to have it always start right away and not wear out my battery and starter?
Thanks for your help!
Barrett
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,446
Reaction score
8,679
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
You shouldn't need an electric pump,they didn't need them new. What carbureator and fuel pump do you have. Should be quadrajet and a 3 port mechanical pump. Check and post back
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,250
Reaction score
17,174
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
I just purchased an 86 C10 with a 350 and it runs great and starts at the turn of the ignition…that is if I start it every day, however, if I let it sit for a couple days I have to crank and crank to get the fuel filter to fill up and get gas to the carb. Once the filter is full it will start perfectly but after a couple days of not being started the issue repeats.
Do I need to install and electric fuel pump to have it always start right away and not wear out my battery and starter?
Thanks for your help!
Barrett
Nope. Mine does the same thing. It doesn't wear out the battery or starter, just give it the full press before turning the key, turn it over for a second or two, give one to two pumps, and do it again. If it doesn't start, only one more pump, and try a third time.

I may get blasted for it that way and suggesting here, but I hate dry rotating an engine, so I try to get the fuel in the carb quickly, and less rotating with the starter and faster firing
 

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
2,027
Reaction score
2,929
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
Think about it this way. How many new trucks would have been returned to the dealer if this was normal? GM did not install electric pumps; they didn't need it.

However if they sit for a few days fuel will evaporate from the carb. Could also be fuel leaking out of Q jet well plugs, weak pump, fuel drain back or choke issues.

All of my carb vehicles have extended cranking after sitting a few days, not horribly long may be 5-10 seconds. That's normal.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,250
Reaction score
17,174
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Think about it this way. How many new trucks would have been returned to the dealer if this was normal? GM did not install electric pumps; they didn't need it.

However if they sit for a few days fuel will evaporate from the carb. Could also be fuel leaking out of Q jet well plugs, weak pump, fuel drain back or choke issues.

All of my carb vehicles have extended cranking after sitting a few days, not horribly long may be 5-10 seconds. That's normal.
^^^^^^THIS^^^^^^
 

Copymutt

Full Access Member
Joined
Jan 17, 2020
Posts
222
Reaction score
673
Location
Colorado
First Name
Jim
Truck Year
74
Truck Model
K20
Engine Size
350
Common for carbs that sit for extended periods. Elec. pump as a primer will fix it. Or borrow that little squeeze bulb off one of your chain saws!
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,446
Reaction score
8,679
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
If it has a windowed needle and seat with a leaking needle and the incorrect or no fuel filter installed it will do this. It will bleed the bowl dry through the return line.
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,970
Reaction score
12,220
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
Doesn’t need an electric fuel pump. But not normal for sitting a few days or weeks or months. Needs a little carb work sounds like.
 

Barrett-FL

Junior Member
Joined
Nov 5, 2023
Posts
18
Reaction score
15
Location
Central Florida
First Name
Barrett
Truck Year
86
Truck Model
C10
Engine Size
350
Thank you all for your replies!

The carbonator and intake manifold are Edelbrock.

I was thinking of having the electric fuel pump as a primer as Copymutt suggested.

Not sure what a "widowed Needle" is.
 

Attachments

  • IMG_0603.jpg
    IMG_0603.jpg
    178.1 KB · Views: 38

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
2,451
Reaction score
3,819
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
Windowed style on the left, solid on the right.
 

Attachments

  • IMG_8597.jpeg
    IMG_8597.jpeg
    81.9 KB · Views: 33
  • IMG_8598.jpeg
    IMG_8598.jpeg
    61.4 KB · Views: 32

vintovka

Member
Joined
Feb 16, 2017
Posts
47
Reaction score
47
Location
or
First Name
vin
Truck Year
84
Truck Model
k10
Engine Size
350
Someone said running a electric BEFORE the mechanical affected the diaphragm in the latter. Not sure how it would work with electric after mechanical for start ups. Mine now starts fine with just the Mechanical and one pump before starting.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,446
Reaction score
8,679
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Someone said running a electric BEFORE the mechanical affected the diaphragm in the latter. Not sure how it would work with electric after mechanical for start ups. Mine now starts fine with just the Mechanical and one pump before starting.
Electric pump before the stock mechanical pump is just fine. If you use an electric pump,with no anti siphon valve or anti drain back valve the electric pump doesn't even need to run full time fuel will free flow through it. So a monetary contact switch,push the button,prime the system,release the button start your car. You do not want to mount an electric pump far from the tank ,and you want to keep it below fuel level. Pumps push better than they pull.When I mount one I angle the pump so the outlet is slightly higher than the inlet so the pump always has fuel in it,preventing dry starts. A facet 40106 would be a good choice as a primer pump. They are USA made and ethanol compatible,they are very noisy though so just use as a primer pump.
Edit, when running an electric pump solo, I blow through a factory pump on the engine block, no pushrod behind it. That way I can use all my factory hardlines,fuel supply, carbureator supply,and return. If running an electric pump,solo this way you may have to put a restrictor in the return line to keep from bypassing too much fuel.
 
Last edited:

Walstw01

Junior Member
Joined
Sep 28, 2023
Posts
15
Reaction score
34
Location
55314
First Name
Wade
Truck Year
1979
Truck Model
K25
Engine Size
355
Hmmm. I have the same problem. Fresh rebuild, edelbrock intake, Holley 4175 (quadrajet replacement) ... If I start it every day, fires up no problem. Wait a week before starting and ... Pump-Pump-crank-crank-crank-pump-pump-pump-crank-crank-crank ... etc. I know there is plenty of fuel in the bowl, because the last few times, before starting, I popped the hood and manually operated the throttle. Squirters squirt fuel. There is a clear external fuel filter and, as far as I can tell, the fuel is draining back through the (new) mechanical fuel pump. If the filter is full of fuel, truck starts right up. If filter is mostly empty, it takes several attempts to start.

I used to have a 69 Chevelle with a built 35o, Weiand intake and Holley double pumper. That thing could sit for 6 months and it would fire up on the second cranking revolution every time (in fact, my father-in-law used to brag to people about it).
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,446
Reaction score
8,679
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Hmmm. I have the same problem. Fresh rebuild, edelbrock intake, Holley 4175 (quadrajet replacement) ... If I start it every day, fires up no problem. Wait a week before starting and ... Pump-Pump-crank-crank-crank-pump-pump-pump-crank-crank-crank ... etc. I know there is plenty of fuel in the bowl, because the last few times, before starting, I popped the hood and manually operated the throttle. Squirters squirt fuel. There is a clear external fuel filter and, as far as I can tell, the fuel is draining back through the (new) mechanical fuel pump. If the filter is full of fuel, truck starts right up. If filter is mostly empty, it takes several attempts to start.

I used to have a 69 Chevelle with a built 35o, Weiand intake and Holley double pumper. That thing could sit for 6 months and it would fire up on the second cranking revolution every time (in fact, my father-in-law used to brag to people about it).
What fuel pump do you have on it? A 3 port has no check valve in the return and they can bleed back. But if there is fuel in the bowl and you have accelerator pump shot it should fire,have you actually looked at the accelerator pump shot? Or just heard it and saw vapors?
 

Latest posts

Forum statistics

Threads
44,157
Posts
950,585
Members
36,271
Latest member
jstewart7501
Top