LaidbackLukas

As soon as I turn my key to the "On" position, I can hear the fuel pump running. This could be totally normal, but it strikes me as odd as every other car I've owned or had experience working on only seems to begin to prime the fuel pump when the key is "On". They definitely haven't immediately began to run the fuel pump before the car is running.

Just wondering if this is normal or not and, if not, what I should do to fix it.

Ps- the car is an '84 GS if that helps with any sort of diagnosis

vipernicus42

iTrader: (4)

For Model Years 1979-1983 this is normal. In 84-85 they added a fuel pump relay which makes the pump only work when the engine is running.

There are pros and cons to both setups. The obvious pro is the safety aspect. If you flip your car into a ditch the engine shuts off, but if you don't have the relay the fuel pump will keep pumping fuel into your carb (which will leak out because the floats are upside down), making a dangerous situation. The con is that if your car has been sitting for a while (like when mine is in storage for the winter) and you need to run the fuel pump for a few seconds before starting up to fill the float bowls so that you don't crank dry, you can't unless you jump/bypass the relay.

I've got my relay sitting in my glove box. Still debating whether to reinstall it.

Cheers,

Jon

LaidbackLukas

Okay, so this is normal on 79-83 cars, but not necessarily on an 84? I guess that means sometime along the life of this car the relay was removed or bypassed in some way. I guess I'll leave it be as long as it continues to work haha. Thanks for the quick response.

vipernicus42

iTrader: (4)

The relay is pretty easy to get to. It's under the dash on the driver's side near the steering column. If it's there it's a small cylinder that's brass- or steel-coloured with a 6-pin connector attached to it. If it's not there on an 84-85 model you should see some kind of jumper cable connecting two of the pins in the six pin connector.

If you decide that you want one I'm sure someone on here has a spare they could part with.

DreamInRotary

iTrader: (49)

I jumped mine to make sure the fuel pump turns on with the key in the "ON" position. I like to be able to hear it before I start cranking the car.

j9fd3s

iTrader: (3)

i've seen the ECU fail on the 84-85 cars, so that the pump isn't turned on when it should be. best thing to do is to bypass it and just set it up like the 83 and older cars. there is a roll over check valve, so if you're upside down, it will physically cut the fuel line

vipernicus42

iTrader: (4)

The roll over check valve fails way more often than the ECU. I've bypassed mine because it died years ago and cut fuel flow completely, never bothered replacing it.

RustyRotary

iTrader: (2)

Where is the rollover check valve and is it easy to test its operation?

Rolling over sounds unpleasant enough, don't need to add fire and explosions to the mix

DivinDriver

iTrader: (15)

It's mounted near the gas tank, aft of and above the fuel pump.