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 11-30-2011, 09:29 AM   #1
Telecasterjoey
Registered User
 
Join Date: Nov 2010
Location: Ottawa ON
Posts: 514
Electric fuel pump questions??

Hey guys so I'm in the middle of my engine swap and now I'm at another road block. I need to use an electric fuel pump because the 1990 block I'm using doesn't have a casting for the mechanical (trust me I'd rather run one) After a search on here I still have a few questions.. To run my rochester q-jet I'll need around 5 psi correct? If I run an electric fuel pump do I need the return line?
How hard are they to wire up? And does anyone sell the entire kit with an oil pressure safety switch? How do you guys run your pumps?? Lots of questions I know!

Here are some pictures of the swap so far.
Pulled the van 350 first, pulled the truck 305 now I'm just cleaning and painting everything.
Attached Images
     
Telecasterjoey is offline   Reply With Quote
Old 11-30-2011, 09:43 AM   #2
Your41Plague12
Registered User
 
Your41Plague12's Avatar
 
Join Date: Dec 2010
Location: Pittsburgh, PA
Posts: 1,009
Re: Electric fuel pump questions??

When my truck had an engine with the TBI block, we capped the return line and ran a pressure regulator for whatever carb I was running at the time. They're really easy to wire up. Wire it to where it has 12V when the key is on. If there is a way to keep it from coming on when the key is on ACC, do that (or just install a killswitch for whenever you need to use the electronics but don't want the fuel pump to run). Mine ran great, but prepare; if you mount yours on the frame rail, like I did, you will have the most annoying sound from the fuel pump echoing off the inside of your cab. It will drive you insane.
__________________
Steve
Member of the Foot Pedal Club
'83 Chevy K20: 6" Rough Country, 3" Performance Accessories BL,
Bushwacker Cutouts, 38x15.50 Mickey Thompson Baja Claws,
350 HP 350 crate engine from Jegs, Turbo 400
Your41Plague12 is offline   Reply With Quote
Old 11-30-2011, 09:56 AM   #3
East End K5
Registered User
 
Join Date: Nov 2004
Location: Long Island NY
Posts: 293
Re: Electric fuel pump questions??

not to hijack but how beneficial is running an electric fuel pump to a carbureted engine? Im a novice....lol.
__________________
I feel sorry for people who don't drink....because when they wake up in the morning, that's the best they're gonna feel all day long!---Frank Sinatra RIP

[B]1972 Chevrolet K5 Blazer RIP
1986 GMC Sierra K3500 1TON, Long Box, V8350 RIP
1980 Chevy Silverado C30 Cab and Chassis, 454 TH400HD. RIP
[B] 1995 Chevrolet Tahoe 2D [B]
East End K5 is offline   Reply With Quote
Old 11-30-2011, 10:11 AM   #4
Your41Plague12
Registered User
 
Your41Plague12's Avatar
 
Join Date: Dec 2010
Location: Pittsburgh, PA
Posts: 1,009
Re: Electric fuel pump questions??

Quote:
Originally Posted by East End K5 View Post
not to hijack but how beneficial is running an electric fuel pump to a carbureted engine? Im a novice....lol.
If you have electrical issues like I did, it sucks. Plus the wires are exposed and can corrode, making the pump fail. I honestly prefer the mechanical pumps, that's why I got rid of the TBI block.
__________________
Steve
Member of the Foot Pedal Club
'83 Chevy K20: 6" Rough Country, 3" Performance Accessories BL,
Bushwacker Cutouts, 38x15.50 Mickey Thompson Baja Claws,
350 HP 350 crate engine from Jegs, Turbo 400
Your41Plague12 is offline   Reply With Quote
Old 11-30-2011, 11:23 AM   #5
notyo_cheez
Registered User
 
Join Date: Apr 2011
Location: corpus christi, tx - america's fattest city
Posts: 253
Re: Electric fuel pump questions??

You need a 12V relay (to the control circuit side) tapped from the feed to your coil upstream from your fuel pump, this way the pump won't run when you have your key on ACC. Make a hot tap and dedicated fuse from your fuse panel for the power circuit for the fuel pump.

When you turn the key the 12V feed to your coil will energize the coil for the relay, closing the contacts on the relay and turning on the fuel pump. This is the correct way.
notyo_cheez is offline   Reply With Quote
Old 11-30-2011, 07:15 PM   #6
Restrorob
The One And Only !!!
 
Restrorob's Avatar
 
Join Date: Jan 2007
Location: Hole in the woods Florida
Posts: 4,567
Re: Electric fuel pump questions??

Quote:
Originally Posted by Telecasterjoey View Post
To run my rochester q-jet I'll need around 5 psi correct? If I run an electric fuel pump do I need the return line?

5 or 6 psi is fine, But it's always best to run a return line. This reduces back pressure which can reduce amp draw of the pump motor and the noisy cavitation associated with frame mounted pumps.
__________________
93 Jeep XJ
88 Buick La Sabra
Toys;
88 TA-GTA in the works....
97 GMC Ext. Cab
502 Crate 5 Spd......Sucks Gas But Haulz Azz !


The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic.


"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!
Restrorob is offline   Reply With Quote
Old 11-30-2011, 10:54 PM   #7
raceman6135
Dino burner
 
raceman6135's Avatar
 
Join Date: Nov 2002
Location: Calgary, Alberta, Canada
Posts: 602
Re: Electric fuel pump questions??

Quote:
Originally Posted by Telecasterjoey View Post
To run my rochester q-jet I'll need around 5 psi correct?
Correct. Anything from 5 to 7 PSI is acceptable.

Quote:
Originally Posted by Telecasterjoey View Post
If I run an electric fuel pump do I need the return line?
It depends upon the pump. Some require a return line, but most that are set up to run with carburetors at this pressure do not require a return line.

Quote:
Originally Posted by Telecasterjoey View Post
How hard are they to wire up?
Fairly easy. The pump needs to be grounded to a good chassis ground. The power wire can be run to an unused IGN terminal in the fuse block. IGN terminals in the fuse block will only supply power to the fuel pump when the key is in the "ON" position. As with any electrical connection, though, use a test light or meter to be sure. Also, remember to support the wire every 12 inches or so and keep it away from heat and moving parts.

Quote:
Originally Posted by Telecasterjoey View Post
And does anyone sell the entire kit with an oil pressure safety switch?
Not that I'm aware of.

Quote:
Originally Posted by Telecasterjoey View Post
How do you guys run your pumps??
Just the way I've described.

Don't forget that electric fuel pumps are not very good at pulling fuel; they are designed to push. Therefore, mount the pump as low and as far back (right beside the tank if possible) in the vehicle as possible.

Keep the amount of rubber hose you use to a minimum, and be sure to size all fittings, hoses and hose clamps properly.
raceman6135 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 11:05 PM.


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