Mechanics

FUEL PUMP PROBLEM

1985 Toyota Camry

The car would sometimes refuse to start. Eventually the car was towed to repair shop. The problem was traced to inability of fuel, sometimes, to reach the engine from the fuel tank. The fuel tank was removed and cleaned. The mechanic also changed the fuel pump. The engine started after these procedures were done.

Immediately after I left the repair shop I noticed that the engine would stop if I go down an inclined surface. I tested inclining the car, with its nose slightly lower than its tail, and engine would stop in this position every time. No problem as long as the car is in a level position.

Suspecting that fuel gauge might be in error (on the theory that the part of the fuel tank where the intake pipe of the fuel pump is located "dries up" when the car is inclined forward) I filled up the tank with more gasoline until the gauge showed half tank. The problem was solved. Engine no longer stops even when tilted forward. But, as soon as the fuel gauge edges down a little bit (still one-fourth tank) the problems recurs.

What could the problem be?
1. Erroneous fuel gauge?
2. The position of the intake pipe of the fuel pump in a wrong position?

I noticed during the repair procedures in the repair shop that the mechanic punched a hole on a wall that immediately surrounds the fuel pump in the fuel tank. I don't know why he did that and I failed to ask. Could that be the cause of the problem why the engine would stop when the car is inclined forward?

I am a missionary in Cambodia where Toyota Camry is the most used car. I bought mine from another missionary who have used it for more than a decade. I do my best to keep it running at the least possible expense. The problem is, it is hard to communicate to local mechanics that can only speak Khmer.

I would be very grateful for your help. Thank you very much.
Avatar
MartTayo
September 9, 2013.



It sounds like you are running out of gas even though the fuel gauge shows you have gas.

To: Jacobandnickolas,

Your observation is correct. The problem appears like I have suddenly ran out of gas.

It happens only when the car is inclined forward, with the nose a little lower than its tail, such as when you are going down from a slightly elevated portion of the road, or even just from a slightly elevated driveway. However, I know that when it happens there is enough gasoline in my tank.

Thank you for your prompt attention.

Tiny
MartTayo
Sep 10, 2013.
I would first make sure that the fuel gauge is reading correctly. Also, keep in mind, the pump is between the center and rear of the tank, so if it is low on gas, it may not pick up the fuel. If that gauge is working properly, I would remove the pump and check the sock (screen) at the bottom to make sure it isn't partially plugged. If it is, it may be requiring the fuel level to be higher.

Thank you.

Let me review below my understanding of the analyses: 1. The fuel gauge may not be reading the level of gas correctly.
(At the moment I find this analysis to be plausible.)
2. The sock at bottom of fuel pump could be partially plugged.
(I am not familiar with the screening configuration, but on this analysis I may understand that there are inlet-holes from lower to upper portion of the intake tube, and that if the lower inlet-holes are clogged the level of gas has to be higher to reach the upper inlet-holes that are not clogged.)

What I will do, basing on the analyses above: 1. I will have the fuel gauge removed and checked for accuracy.
2. I will have the fuel pump removed and have the sock (screen) at the bottom (Is this the intake tube of the pump?) Checked for any plugs. (Does "plugs" here means sediments or dirt, or an adjustable mechanism for controlling flow of fuel?)

By the way, just as an added information that may be useful for analysis, when the car is inclined towards the back, that is, the nose is higher than the tail, the engine continues to run normally.

Thanks, again. It is really comforting to be able to communicate about these things to people who can make analyses and communicate back intelligently.

Tiny
MartTayo
Sep 10, 2013.
I'm glad to help. And yes, the sock or screen is over the inlet. If it gets dirt in it, the pump will not be able to pick up fuel at certain levels. Based on the fact that the position of the vehicle determins if it will start, that makes me believe there is a problem in that area.

Yes, Sir, I will check on that area (the sock on the inlet of the fuel pump) as soon as I can. I will let you know what I will find and on how things will come out.

Thank you very much. I will keep in touch.

Tiny
MartTayo
Sep 11, 2013.
I will look for your reply.

Joe