FUEL PUMP TECH
Fuel pumps can be a common problem for Toyota owners as the age of these pickups are up there in years. Vehicles with over 100,000 miles and have driveability issues, may need to change the fuel pump to get the life back in there engines.
Faulty fuel pumps can cause many issues. The worst one is a no start condition. Other fuel pump problems may present themselves in other ways, cutting out, hesitation, low power and stalling at the worst time but then restarting after some time has gone by. The last one means the pump is most likely over heating after it cools again it starts working.
The in tank pumps found on a majority of the pickups actually use the fuel as a way of cooling the pump. Running around on E all the time is one way to shorten the life of an in tank fuel pump. You should run at least half a tank of gas all the time to keep the fuel pump running cool.
The fuel system consists of a fuel tank electric fuel pump in the tank a fuel filter and a fuel rail were there is a regulator and a pulse dampener then on to the injectors which will spray fuel into each cylinder. LC Engineering has come up with a inexpensive way of checking fuel pressure not at the fuel rail but at the cold start injector. Kit number 2019128 will allow you to see the regulated fuel pressure. This kit can also be left on to monitor fuel pressures all the time. Other factors in the Toyota fuel system are, ready for this one that trap door mass air flow meter, yes this part is what actually turns the pump on though a relay that is located above the computer on the passenger kick panel. As soon as you start cranking the engine over the trap door will open with the air being sucked into the engine. This in turn will activate the fuel pump relay that will energize the fuel pump.
As we stated before driving around on E can shorten the life of the fuel pump, so can a clogged fuel filter making the pump work harder shortening its life. Poor fuels as well as dirty fuels all make the life of the fuel pump a hard one. Proper trouble shooting is needed to see were the problem lies, but if you know that the fuel filter has not been changed at the recommended intervals then that is one thing that should be done no matter what the problem. Filter removal will be a lot less dangerous and messy if you relieve system pressure first. Remove the fuel pump fuse, and crank for 20 seconds. The fuel filter on the 22re is located under the intake manifold. Not a fun spot but can be accessed best though the fender well or from underneath. The 3vz trucks fuel filter is found on the frame rail.
The fuel pump is electrical some times the problem is just that electrical. Trouble shooting electrical problems can be difficult. Click HERE to get a PDF a excerpt from a factory service manual that will go into electrical trouble shooting for the fuel system.
Pump replacement is difficult on the Toyota trucks. Most of the time it is required that you drop the tank, which can be quite an undertaking, especially if you've just filled up (gasoline weighs 6 pounds per gallon). There are a few ways at getting the tank out. Some Toyota's have a drain on the gas tank. This makes it the easiest to drain. You may have to siphon the fuel out this should be done with caution in a well ventilated area with out the use of power tools. Be sure NO SMOKING when around fuel. Another way is if you have a good floor jack, put a big square of plywood between it and the tank. Remember that there's still a certain amount of fuel in the tank after you've drained it. Click HERE to see the instructions for fuel pump change.