Gas pump question

[Buzo]

I mentioned before that my neighbor has a couple of 3geez and he said he can hear the pump spinning only for a couple of seconds after oppening the key, then it shuts off. In both cars.

In the electric diagrams there is no such timer for the fuel pump, but since I only have seen my car -and the pump is always running- I would like to ask if other carbureted cars really does what this guy says. Maybe he is right...

[Buzo]

I am going to make it easier for you

1.-Tomorrow morning, before you fire up your car
2.-Put the drivers window down
3.-Open the key to the ON position
4.-Listen to the pump in the tank
5.-Does it turn off after a second or two?
6.-Please, post your findings in Buzo's thread!

[RAZR]

My fuel pump turns on for about 2 second untill it builds pressure in the fuel lines and then it shuts off

Is the problem that his cars don't start?

[charliekuney]

I can hear mine with the windows up. I can hear it buzz for about two seconds.

[stephensimmons]

I can hear mine with the windows up. I can hear it buzz for about two seconds.

Mines the same way.

[stephensimmons]

I mentioned before that my neighbor has a couple of 3geez and he said he can hear the pump spinning only for a couple of seconds after oppening the key, then it shuts off. In both cars.

In the electric diagrams there is no such timer for the fuel pump, but since I only have seen my car -and the pump is always running- I would like to ask if other carbureted cars really does what this guy says. Maybe he is right...

Hummmmmmmm............. If ypur car is carburated then yes your fuel pump is going to run all the time. BUT if your car is fuel injecter then it will run for about 2 seconds when it is first switched on then after you start it then it will run continuous. The reason being is when a fuel pump is added to a carburated car it is usually wired into the ignition switch and on the fuel injected cars the fuel pump is controlled by the computer and a relay.

[Dr_Snooz]

A properly working fuel pump should stop pumping when the line is sufficiently pressurized.

[stephensimmons]

A properly working fuel pump should stop pumping when the line is sufficiently pressurized.

True. If it is wired straight to the ignition switch it will continue to run even after it build pressuter though. I think thats why his keeps running and also he said his car is carburated. I dont know if the caburated cars pumps stop working after building pressure or If they even came with electric fuel pumps?

[Buzo]

.... I would like to ask if other carbureted cars really does what this guy says. Maybe he is right...

For those that answered, thanks. But could you please tell me now if your cars are carbureted?

[lostforawhile]

your timer is built into the safety relay for the fuel pump on the carb car. the pump won't run unless it detects ignition pulses from the engine running, it runs for a second or two to prime the system before you start the car, the relay cuts off fuel if the engine stops to prevent a fire hazard in a wreck, the pumps, both carburated and fuel injected, run constantly when the engine is running, they are rotary pumps, not diaphragm pumps

[Buzo]

Ok, mine is always running, so there may be something wrong with the fuel cut-off relay.

I'll check it up and see where the problem is.

Thanks everyone for your inputs.

[lostforawhile]

Ok, mine is always running, so there may be something wrong with the fuel cut-off relay.

I'll check it up and see where the problem is.

Thanks everyone for your inputs.

you mean with the engine off? if it's a carb it should be off with the engine off

[Buzo]

you mean with the engine off? if it's a carb it should be off with the engine off

Exactly, as long as the key is ON, the pump is ON, even with the engine not fired up.

I removed the pump cut off relay, opened the Key to the ON position and the pump starts up. It don't care the cut-off relay is not in its place.

So the pump is directly connected to the Ignition signal somewhere else.

I think I got something to do over the weekend...

[lostforawhile]

Exactly, as long as the key is ON, the pump is ON, even with the engine not fired up.

I removed the pump cut off relay, opened the Key to the ON position and the pump starts up. It don't care the cut-off relay is not in its place.

So the pump is directly connected to the Ignition signal somewhere else.

I think I got something to do over the weekend...

on the of the pump relay you have four pins, ignition power, ground, tach signal, (- terminal of coil, blue wire) and + out to the pump, you could put the relay somewhere else if needed and just run a new wire from the pump positive wire in to the pump voltage out of the relay, one good place if you have to move it, is right on the side of the blower housing, or in that area, are all the connections you need including the tach signal, they all go into the ac delay box plug, it has a rev limiter for the AC compressor, hence the tach wire

[Buzo]

I got lucky this time.

I opened the hole in the trunk to gain access to the fuel tank cover, and I could see an external wire connected straight to the pump +.

This car had problems with the tacho signal when I bought it, the tacho in the dashboard was constantly turning on and off. So I fixed that sometime ago.

I assume, the lack of tacho signal was causing the pump to shut on and off at the same time as the tachometer in the dashboard. Then the previous owner connected a +ignition signal to the pump to circumvent that failure

I just disconnected that wire, and since my tacho signal is now OK, the pump is doing now what it is supposed to do: Turning ON for a second after I open the key, but it shuts off If I don't crank the car.

Bottom line, problem fixed.