Fuel Pump Help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hdrider · 09-14-2009, 08:13 PM

i have a 1982 GMC 1/2 ton 5.0L...i had to replace the fuel tank and sending unit on this truck because it was shot due to rust...i also replaced the fuel pump...i cant get gas to the pump from the tank...i primed the fule line from the carb but once that gas is pumped out, thats it...seems like its vapor locked...how can i get the fuel to feed up to the pump from the tank...i cranked the hell outta it & it would start to feed then stop, cant get a good flow...thanks

gchemist · 09-14-2009, 09:08 PM

The pump rod is probably not hitting the pump lever. Remove the pump. Use lithium or rebuild grease to hold the pump rod into the block. Install the new pump carefully. Crank it over. Fuel should come out the supply line to the carb.

hdrider · 09-14-2009, 09:23 PM

thanks for the reply...dont think thats the prob because i replaced the tank after the pump & it was pumping from the old tank fine & thats when i noticed all the crud in the gas, droped the tank & seen it was too far gone & i replaced it & the sending unit.

Primer70 · 09-14-2009, 09:29 PM

I had a 76 GMC that the rubber fuel lines were coming apart from the inside & plugging up the fuel line. I'd replace all the rubber lines & blow compressed air though the steel lines to be sure they are not blocked.

hdrider · 09-14-2009, 09:38 PM

thanks...blowing compressed air back to the tank is my next move...the truck sat for a long time & now im having these problems getting it going again...what if it blows back fine & gas still isnt comming to the pump???...thanks

**old Rusty C10** · 09-14-2009, 11:11 PM

im going to go along with the others and say its prolly more of a blockage than anything else... have you checked the fuel filter in the carb too?

Prong · 09-15-2009, 05:25 AM

Maybe you accidently swapped the lines on the sender (the feed and vapor lines).

hdrider · 09-15-2009, 07:01 AM

running a holly carb & external fuel filter...have line disconnected befor filter when i crank it to check for flow...lines arnt crossed, 3 different size lines, i checked that...thanks

Damien · 09-15-2009, 11:10 AM

Somewhere recently I read about some one having this problem and it turned out to be a big glob of solder plugging up the sender.

hdrider · 09-15-2009, 11:58 AM

nope...i blew in every line on sending unit befor i put it in but thanks

WRKTRUK · 09-15-2009, 02:02 PM

Had it happen to me, what was wrong for me was when I finally managed to get the tank back in it's location I didn't realize I had folded the feed line on top of itself, well pulled the bed off this time and could just get to it to straighten it back out. I dunno if that's what's going on with yours or not, but mine did the exact same thing until I finally started back tracking and realized that the rubber line had a nice 90* bend right up against the cab of the truck.

09-14-2009, 08:13 PM	#1
hdrider Registered User Join Date: Feb 2008 Location: oldsmar fl Posts: 22	Fuel Pump Help i have a 1982 GMC 1/2 ton 5.0L...i had to replace the fuel tank and sending unit on this truck because it was shot due to rust...i also replaced the fuel pump...i cant get gas to the pump from the tank...i primed the fule line from the carb but once that gas is pumped out, thats it...seems like its vapor locked...how can i get the fuel to feed up to the pump from the tank...i cranked the hell outta it & it would start to feed then stop, cant get a good flow...thanks Last edited by hdrider; 09-14-2009 at 08:55 PM.

09-14-2009, 09:08 PM	#2
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: Fuel Pump Help The pump rod is probably not hitting the pump lever. Remove the pump. Use lithium or rebuild grease to hold the pump rod into the block. Install the new pump carefully. Crank it over. Fuel should come out the supply line to the carb. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

09-14-2009, 09:23 PM	#3
hdrider Registered User Join Date: Feb 2008 Location: oldsmar fl Posts: 22	Re: Fuel Pump Help thanks for the reply...dont think thats the prob because i replaced the tank after the pump & it was pumping from the old tank fine & thats when i noticed all the crud in the gas, droped the tank & seen it was too far gone & i replaced it & the sending unit.

09-14-2009, 09:29 PM	#4
Primer70 Superbad Join Date: Mar 2007 Location: Pittsburg, CA Posts: 153	Re: Fuel Pump Help I had a 76 GMC that the rubber fuel lines were coming apart from the inside & plugging up the fuel line. I'd replace all the rubber lines & blow compressed air though the steel lines to be sure they are not blocked.

09-14-2009, 09:38 PM	#5
hdrider Registered User Join Date: Feb 2008 Location: oldsmar fl Posts: 22	Re: Fuel Pump Help thanks...blowing compressed air back to the tank is my next move...the truck sat for a long time & now im having these problems getting it going again...what if it blows back fine & gas still isnt comming to the pump???...thanks

09-14-2009, 11:11 PM	#6
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,313	Re: Fuel Pump Help im going to go along with the others and say its prolly more of a blockage than anything else... have you checked the fuel filter in the carb too? __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

09-15-2009, 05:25 AM	#7
Prong Registered User Join Date: May 2007 Location: CO Posts: 475	Re: Fuel Pump Help Maybe you accidently swapped the lines on the sender (the feed and vapor lines).

09-15-2009, 07:01 AM	#8
hdrider Registered User Join Date: Feb 2008 Location: oldsmar fl Posts: 22	Re: Fuel Pump Help running a holly carb & external fuel filter...have line disconnected befor filter when i crank it to check for flow...lines arnt crossed, 3 different size lines, i checked that...thanks

09-15-2009, 11:10 AM	#9
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	Re: Fuel Pump Help Somewhere recently I read about some one having this problem and it turned out to be a big glob of solder plugging up the sender. __________________ I can still count my vehicles on two... wait three hands.

09-15-2009, 11:58 AM	#10
hdrider Registered User Join Date: Feb 2008 Location: oldsmar fl Posts: 22	Re: Fuel Pump Help nope...i blew in every line on sending unit befor i put it in but thanks

09-15-2009, 02:02 PM	#11
WRKTRUK Registered User Join Date: Jan 2009 Location: Meridian, MS Posts: 12	Re: Fuel Pump Help Had it happen to me, what was wrong for me was when I finally managed to get the tank back in it's location I didn't realize I had folded the feed line on top of itself, well pulled the bed off this time and could just get to it to straighten it back out. I dunno if that's what's going on with yours or not, but mine did the exact same thing until I finally started back tracking and realized that the rubber line had a nice 90* bend right up against the cab of the truck. __________________ 1984 Longbed Silverado with an 86' 4-Bolt main 355ci 10:5:1 flat tops, 268 cam, stock trim, rally wheels (fast and ugly), My daily driver 1972 Custom/10 Shortbed 4x4 4spd, bone stock 89,000 original miles one owner truck (very rusty, but original)



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.