My 1979 Toyota 4x4 and has been giving me trouble when I get below 1/2 a tank of gas. It acts like it is running out of fuel. Since I had some down time (due to a achilles tendon problem) I pulled the tank to see if I could find the problem figuring I would likely find a broken pickup tube or something similar causing the problem. This truck has a 22R with a mechanical fuel pump on the motor. When I pulled the tank I find an electric pump in the tank which suprised me as I did not know this year had this type of pump along with the mechanical one. The electric one appears to be bad as it will not do anything...run, draw current, nothing.
My question to all who know much more about this than I do (which is most likely everyone) would the electric pump being bad cause the issue of starving for gas when it gets below a 1/2 tank? It runs fine when above this point. One other thing I have not checked yet is to make sure the vent lines are open and allowing the tank to breathe. I know a stopped up vent will cause the tank to "vapor lock" and not let any gas come out until the vacuum condition is corrected. However I have taken the gas cap off and ran the truck and still had the same problem.
Thanks in advance for any help anyone can provide on this. I've always heard you learn something new every day.............I did not have a clue this truck had two fuel pumps.

Don

 

If you have a 22R as you say, then you shouldn`t have a fuel pump in the tank at all, im betting that someone has replaced the gas tank in your truck at some point, and used a gas tank from a fuel injected truck. you can make what you have work by removing the electric fuel pump and using a piece of hard line extend the fuel pick up to the bottom of the tank and use a piece of metal wire to hold the pick up to the bottom of the sending unit frame so it won`t move around, and it should work just fine. Otherwise you will have to replace the whole sending unit with the right one and they are very expensive.

 

Thanks for the reply myyota. After posting the initial message I did some research and found out that the '79 4x4 did come with an electric pump in the tank for the 20R motor. The motor in the truck is out of a '83 which had the mechanical pump. I have a rolled '83 and will most probably take the tank out of it and put it in the '79. Hopefully this will fix the starving for fuel issue when below 1/2 tank also. If not at least one thing is out of the way.

Thanks again,

Don

 

I'm pretty sure I found the problem today. While the vent line from the tank to the charcoal canister was open the cansiter itself was stopped up not allowing the tank to vent. I'm going to replace it with the one off the spare parts truck..........hopefully this will fix the problem.

Don

 

Yeah for some reason some 20R engines had electric fuel pumps. Strange. Hope you've got it figured out!

 

83. It sure suprised me when I pulled the tank. I guess I should have figured it since the 20R motor in another truck I owned didn't have the mechanical pump. I got the tank back in today and am ready to fill it back up and pressure test it. I am going to put a vent cap/plug on the line going to the canister for the time being. I've got several left over from the old racing days when all the EPA stuff was removed.

I'll let everyone know how it works out. Next thing to do is lower gears to run the 33's.

Don

 

Yeah there was a thread on Marlin Crawler where Marlin chimed in and let people know that certain year 20R's had electric fuel pumps, otherwise I definitely would have never known.

 

hey I've got a 79 with an electric fuel pump. the pump works fine out of tank, but when i put it all back together it wont send any gas to the carburetor. I've checked the line for clogs, heck i even siphoned it up the line to the carburetor(yummy btw). yet the carb stays dry as a bone. any clue? any help would be nice.