FUEL PUMP WON'T STOP CLICKING

[gcoll]

HELP! My car(Austin Healey 3000 BJ8) was running fine the other day but this morning when I turned the key the fuel pump would not stop clicking. I continued to try it and now the fuel pump won"t stop clicking and the needle on the fuel gauge is jumping all over the place. Can anyone lend their expertise? thanks

 

[TimK]

What do you mean by turn the key? On or off? Does the engine start? Are you out of gas? Do you smell gas or see gas leaking?
Correctly operating fuel pumps click at a high rate for a short time until fuel pressure builds up (the float bowls fill and shut off). The fuel pump then clicks at a slow rate indefinitely to maintain pressure. The power to the fuel pump is through the ignition switch. It should turn off when you turn the ignition off. If the pump continues to click at a high rate (with the ignition on), you either have no fuel or a fuel leak or a failed pump that cannot build up pressure.

 

[gcoll]

Thanks for the help Tim I guess I wasn't very clear with the problem. When I turn the key to on the fuel pump clicks at a high rate continuously and dosn't stop clicking at the high rate of clicking. It does stop clicking when I turn the key off. I started the car and let it run for a few minutes all the while the rapid clicking continued and the engine idled very rough. Later I turned the key to the on position and the clicking continued and the fuel gage needle went from 1/4 to 1/2 to full and now holds at full. very strange

 

[Keoke]

You have developed an air leak on the input or output side of the PUMP

 

[TimK]

So your fuel pump is going in reverse and filling the tank???? :laugh:

I can't explain any relationship between the two issues. If you car runs roughly it may be getting some fuel but not enough so the pump is running fast to try to build pressure. If there are no leaks and you have fuel in the tank (check with a long stick) you may have a fuel pump going bad. Get a new one.

 

[TimK]

Keoke, I was typing while you were posting. How do you identify and fix an air leak? How can you have an air leak without a fuel leak?

 

[Keoke]

IF you are lucky a gasoline leak will develope some where in the system.If the problem occurs inside the tank that is a hard one unless you are just out of fuel.----Keoke

 

[bob hughes]

Don't know if this applies but I have heard of problems with things floating around in the tank that get themselves stuck on the fuel pipe to the pump, so that there would be a restriction in the flow of fuel hence the pump trying to build up pressure but failing to do so.

Bob

 

[TimK]

gcoll, the fuel gauge problem sounds like a bad ground. It is very unlikely related to the fuel pump problem.

 

[shorn]

It is possible that rust inside the fuel tank has blocked or partially blocked the intake screen on the fuel line inside the tank. Rust particles can also stop the carb floats from shutting off. That would results is fuel being dumped into the overflow tubes off one or both float chambers. Look under the driver's side of the engine for fuel leaking from the floats. Also check the float bowls for rust particles. To clear a block screen in the fuel tank, you can disconnect the fuel line from the tank and blow some air into the tank. That will only be a short term fix but would identify the problem. A new tank (prefer aluminum) would be needed.

 

[John Turney]

First, look to see if you have any fuel on the ground. If you do, find out where it's coming from.

Second, check the fuel level in the tank with a stick as suggested by Tim.

If you don't have fuel on the ground and you have fuel in the tank, then Bob's idea of having the pump suction blocked is the next step. Do you have a filter between the tank and pump? If so, it may be plugged.

If not, disconnect the pump suction line at the pump and see if fuel runs out. If not, blow some air into it into the tank to see if you can dislodge what is blocking the suction.

 

[Bob_Spidell]

Sounds like an inlet leak at the pump. Have you checked the banjo bolts at the pump for tightness lately? They work loose over time and if you have an older pump they use fiber washers which can compress causing loose bolts and loss of seal.

 

[DerekJ]

Rust and particles in the tank is a real possibility. I had that problem on and off for months, took out the tank several times and thought I had cleaned out all the crud, but I hadn't. Finally bought a new aluminium tank.

Has your car been restored and if so do you know if a new tank was insstalled or the old one re-sealed? If not that thing might have been there for 50 years.

I also had a constantly clicking fuel pump caused by a poor quality filler cap that in turn led to a vacumn being created when the fuel was being consumed. The clicking arrived when the tank got to about a third full after the tank had been full. Of course if you fill up regularly the vacumn is released so the clicking disappears or never begins. Probably not the cause in your case but bear it in mind.