Not picking up fuel

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   I recently replaced my tank and gas sending unit and rubber lines, and now that I'm ready to start up my car it seems to not want to pull any gas. Before I started the whole process everything worked, and now it seems not to. 22 gallon tank and it's got 15 gallons in it so I cant imagine the pickup isn't getting it, but I have no idea what could be causing it when everything was fine before. I'm going to attempt to pull straight out of the fuel can and into the pump and I'll find out if my pump is bad, but is there any other culprit? I'll probably replace the pump anyway, so could I use some compressed air to blow out and debris in the fuel line?

Edited by CoffinMaster - Oct/14/2018 at 12:26am

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CoffinMaster Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/02/2018 Location: Los Angeles Status: Offline Points: 100	Post Options Post Reply Quote CoffinMaster Report Post Thanks(0) Quote Reply Topic: Not picking up fuel Posted: Oct/13/2018 at 11:24pm
	I recently replaced my tank and gas sending unit and rubber lines, and now that I'm ready to start up my car it seems to not want to pull any gas. Before I started the whole process everything worked, and now it seems not to. 22 gallon tank and it's got 15 gallons in it so I cant imagine the pickup isn't getting it, but I have no idea what could be causing it when everything was fine before. I'm going to attempt to pull straight out of the fuel can and into the pump and I'll find out if my pump is bad, but is there any other culprit? I'll probably replace the pump anyway, so could I use some compressed air to blow out and debris in the fuel line? Edited by CoffinMaster - Oct/14/2018 at 12:26am
	1973 AMC Javelin AMX, 360 727 1970 Mercury Cougar, 351C AOD

FSJunkie Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/09/2011 Location: Flagstaff, AZ Status: Offline Points: 4742	Post Options Post Reply Quote FSJunkie Report Post Thanks(0) Quote Reply Posted: Oct/14/2018 at 3:23am
	The fuel line from the tank to the pump is likely full of air and these pumps don't pump air through to prime themselves very well. Usually all you need to do is fill the carb float bowl with gas and run the engine. It'll run for 30 seconds or so on the gas in the float bowl and that is usually long enough for the fuel pump to pump out all the air and start pumping fuel up to the carb. If not, the engine will use up the gas in the carb and stall. Then you refill the carb and try again at a higher RPM. Sometimes they need 1500 RPM or so to prime themselves. Weak pumps don't prime well or at all. Leaks in the fuel line from the tank to the pump allow the pump to suck air and it would much rather suck air than fuel. Pumps that were running on an engine but were removed and stuck on a shelf for a while sometimes don't want to prime when they are reinstalled back into service. They dry out inside and don't work well until they get wet with gas again. You can encourage pump priming by blowing your compressed shop air into the fuel filler neck of the gas tank with a rag around it as a seal while running the engine on fuel in the carb. The pressure pushes fuel to the pump. Pumps can be checked. Just put a vacuum/pressure gauge on the inlet of the pump as the engine runs on the fuel in the carb. It should make at least 10" Hg vacuum. Then put the gauge on the outlet of the pump and check for 4-6 PSI. You can do this on the bench by stroking the pump arm by hand. Some pumps are hard to prime but once primed they work fine for years after.
	1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited

CoffinMaster Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/02/2018 Location: Los Angeles Status: Offline Points: 100	Post Options Post Reply Quote CoffinMaster Report Post Thanks(0) Quote Reply Posted: Oct/14/2018 at 5:12am
	Thank you very much, I've not done too much fuel work on lines or tanks, only replaced a few pumps but the priming idea is new to me, I'll try it out, hopefully that should be it.
	1973 AMC Javelin AMX, 360 727 1970 Mercury Cougar, 351C AOD

mmaher94087 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/01/2008 Location: Arizona Status: Offline Points: 1690	Post Options Post Reply Quote mmaher94087 Report Post Thanks(0) Quote Reply Posted: Oct/14/2018 at 10:46am
	Pull the fuel line at the tank side of the fuel pump. Gravity should start the fuel flowing.
	Mike

CoffinMaster Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/02/2018 Location: Los Angeles Status: Offline Points: 100	Post Options Post Reply Quote CoffinMaster Report Post Thanks(0) Quote Reply Posted: Oct/14/2018 at 9:02pm
	It worked very well, I siphoned some gas from a gas can right into the fuel inlet on the carb and it ran until it started sucking up gas. Now just some tuning and hopefully I'll be in the clear
	1973 AMC Javelin AMX, 360 727 1970 Mercury Cougar, 351C AOD