73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Fuel Systems and Drivability => Topic started by: discot315 on May 14, 2010, 08:25:05 pm
-
Just recently, i dont know why but my fuel pump has stopped pumping gas to my carb. I put gas right in the carb and it fired right away but died, i checked the fuel lines to the carb and there ok. Just wondering if i should replace the pump or if its something else. I also noticed that theres a fuel line (from a tank i think) that goes to the fuel pump but isnt attached to anyhting its just hanging by the fuel line thats to the pump. If theres 2 tanks on the truck is there 2 fuel lines? or what is the other one?
If anyone knows anything that could help me it would be great! Thank you
-
If there is nothing connected to your fuel pump you aren't getting gas. Dual tanks feed to a switching valve and the valve feeds the pump.
-
Oh ok, that makes sense. There is the fuel line connected to the pump there is just a nother line there and i dont know what its for, just got a quick look at it today before i had to leave. I will get a better look tomorrow and see where it leads.
Still though cant figure out whats with the pump lol ???
-
did you unhook the fuel line at the carb and crank the engine with the line in a mason jar or something to check volume of pump's action?
is this your 1980?
If your pump is pumping enough fuel, may want to check float/needle inside of carb to ensure it is allowing gas to come in to carb.
-
I was going to try that today but i ran out of time to get to my truck. But the other day when i was at it i manually pumped the throttle on the carb and no gas was coming out so im not sure, but i will definitely try that.
ya its my 1980 with 350 and 4 bbl carb. and the carb was rebuilt about 9 months ago
-
Fuel pumps do just up and quit. I had one in my stock 1981 Jimmy 305 2bbl go out on me. I was with my dad in the truck. He was able to change it in an vacant parking lot after we got some tools. I was 17 at the time. Second time was when I was SURE I had a bum fuel pump again. Dad came out while I was at work and changed it in the snow and cold. Finished up, cranked it, nothing. Hmmmm. Put some gas in it, VROOM! :-X Whoops. Dad wasn't too pleased, but the only thing he said was "Next time, YOU change it." heh
-
Haha thats pretty good, smart thing to check! but ya i have tried a few things quick when i was there. Im at school right now later on today im going to try what SgtDel suggested. I do have a replacment fuel pump im hoping will work if mines dead but i need a new fuel line to the carb for that one to work. Soooooo im hoping mines fine lol ;D
-
You sure that hanging line isn't a return line to the tank? The pump has 3 connections.
One for the fuel supply from the tank.
Another for the fuel going out to the engine.
A third line for returning fuel to the tank.
-
Well I was out at my truck yesterday after work, I did what SgtDel suggested by unhooking the line from the carb and puting it in a container and i cranked it and no gas came out. I took the pump right off but didn't unhook the line to the tank and fuel just poured out of the pump when it was on its side hanging there (not sure if fuel is supposed to or not) And the pump only has 2 connections i checked so not sure what the lines for still. ??? i want my truck running :'( hahaha
-
I bought a new fuel pump and put it on today but still nothing, no fuels even getting to the pump i have now figured out... sooooooooo no idea what it could be now. ??? ??? :( Any suggestions would be great lol
-
But you had fuel in your old pump? How long did you crank it? Try to get the truck running and stay running with wd40 in the carb and see if that will prime the lines and get the fuel up to the carb.
-
Ya there was fuel in the old pump, I cranked it for a little while then i put gas in the carb to see if it would bring more up the line and it fired but burnt it all off and died, i did it a few times. What do you mean about the wd40?
-
Same ideal as fuel in the carb but one its more controlled b more stable if it backfires and c its better than starting fluid. But make sure the fuel line before the pump has no holes in it blow in it and see what happends
-
Take the hose off of the inlet side of the pump & rig up a hose to a can of gas (eliminating the truck's lines & tank) & see if it runs...if so, look for a split hose, kinked line, ect. Not to sound like a jerk, but are you sure there is gas in the tank? Maybe the gauge isn't accurate/gone bad?
Let us know, Lorne
-
Ok thanks im going to try that, i followed the lines back and they seam ok. I have one tank full but the other is empty so my dad said maybe its the switching valve got stuck on the right tank (empty one) so I got gas to put in that tank to see if it will fire. If not il try puting gas in a can and puting it right to the fuel pump. I dont see what else it could be so im hopeing its the switching valve
-
There is another valve in-between the two tanks that could be bad it will do the same thing
-
Isnt that the switching valve though?
-
yup didn't read it right but there's the switch in the cab that could go up and there's a valve that can go up
-
Put gas in both tanks. You need to prime the system now since you ran it dry or you may never get fuel pumping. So before the pump force some fuel into the lines. Have an assistant depress the swich in the cab while you feel the switching valve under the truck. You should feel it click. Your gas gauge should also bounce.
-
Ok so i made sure there was gas in both tanks and primed the system like you said and the truck fired right up! Thanks for the advice it really helps lol. BUT i still think the switching valve is done because i think it only ran on the right tank. I idled it for a while today because it sat since febuary and i drove it a bit to get it closer to the house. And i switched the tanks every so often with the switch but when i was done the left tank said it was still at F and the right tank was almost empty. Im going to try what VileZambonie suggested with feeling the switch. Is the switching valve something you can buy and easily replace? If so where can i buy one? If i need it.
-
http://www.autozone.com/autozone/catalog/parts/partsProduct.jsp?itemIdentifier=125310_173086_5320_&skuDescription=Duralast+/+Fuel+Tank+Selector+Valve&brandName=Duralast&displayName=Fuel+Tank+Selector+Valve&categoryNValue=&sortType=null&store=5152&isSearchByPartNumber=&fromWhere=null&fromString=&counter=0&itemId=1765-0&navValue=14901765&filterByKeyWord=&productId=125310&searchText=&categoryDisplayName=Fuel+Delivery&parentId=49-0
-
http://www.autozone.com/autozone/catalog/parts/partsProduct.jsp?itemIdentifier=18894_173087_5320_&skuDescription=Duralast+/+Fuel+Tank+Selector+Valve&brandName=Duralast&displayName=Fuel+Tank+Selector+Valve&categoryNValue=&sortType=null&store=5152&isSearchByPartNumber=&fromWhere=null&fromString=&counter=1&itemId=1765-0&navValue=14901765&filterByKeyWord=&productId=18894&searchText=&categoryDisplayName=Fuel+Delivery&parentId=49-0
-
Thanks! I did the thing with the switch too, I didnt feel a click but the gas guage switched between the tanks and read them right... does that mean i need a new switching valve?