Mysteries of the GTA fuel system

Hi All,

Just wondering if anyone felt up to giving a brief explanation of how the fuel supply/ priming system works on the GTA (Atmo)?

My car is only starting when it feels like it due to an intermittent fuel supply and I have noticed that sometimes a thump under the dash, (probably shakes the relay, atmo) can bring it back to life.

But as the system seems to have “2” fuel pumps and not much about them in the manual I am not sure how it’s supposed to work i.e.
• Should they both run with ignition?
• Are they controlled by a switch (oil pressure?)
• Do they run independently, maybe have two relays
• Do they both have to work or can the first push enough fuel through?

Sorry to ask so many questions, looking through the threads it seems like this is a common problem on the GTA’s but I couldn’t see a write up of the system as a whole!

Steve.

Atmo, only has one fuel pump (turbo has two), and it is a low pressure feed pump to the carbs. It *should* not be on with ignition, and primes on cranking, but I have a an atmo at the mo, which primes on ignition.

There is a fuel pump relay in fuse box array, so it could be faulty or just have dirty contacts.

Thanks David,

So what is the unit in the OSR of the engine bay under the side cover on an Atmo? On mine this has fuel pipes runing through it and 3 electrical wires, does this mean this is the one pump?

Don't fancy looking underneath today as its raining but I was sure mine had a pump at the front.

Thats the flow meter. It send the signal back to the dash to tell the display the mpg, fuel used ect...

[stephendell]

Yes it's the flow meter, the fuel pump is at the front of the car tucked away near the back of the fuel tank.

Do the turbo's use a flow meter for their trip computer ?