Poorer than normal fuel consumption

[Ron chalk]

I have a 1.8 expression with 53k miles on the clock. I have recently noticed my fuel economy hit the deck to the point of it now being unreasonable to run. It is important to note that i do understand that these are known for their below average poor fuel economy. I am told that the car smells like fuel when running about. Could it be running rich?

Does anyone have any suggestions as to what maybe causing this sudden increase in fuel consumption?

Thanks so much in advance.

[Robsey]

Smelling fuelly.

First check for a fuel leak.
Obvious sites of a leak are:-

1 - The fuel tank seams.
All Cavalier fuel tanks rust on the seams eventually.

2 - Split or leaking fuel hoses or corroded fuel pipes.

Then there is the Central Injector.
Looks like a glorified carburretor.
The injectors can become worn and either be slow to shut, or simply allow too much fuel to leak through.

Engine could be running too rich because the engine coolant temperature sender is telling the ECU that the car is cold all the time. The result is that the ECU applies fuel enrichment (a bit like an electronic choke).

One of the spark plugs is not fully screwed into it's bore, causing inefficient burning of the fuel.

Inlet manifold or exhaust manifold air leak.
This would tell the lambda probe that the engine is running too lean, and so it will tell the engine to use more fuel.

None of these would put an engine light on.

-------------------------------

Other causes would put the engine light on, such as defective lambda sensor.

[Cavalier342]

a 1.8 with 53.000 miles? That should be well economical! Definitely sounds like you got a leak somewhere.

check your fuel filter, too, have a feel at both ends to see if it's wet or stinks of fuel.

[iangsi]

When the O2 sensor started to fail on my 1.8 it ran really y rich & smelt of petrol at times, easy enough to replace screwed into the exhaust down pipe.

[Mk3alan]

My fuel pipe from tank to pump became porous, really smelly I but couldn't actually see a leak as such.
I replaced it with a new GM part which didn't last long at all.
Now I have replaced it with 'normal' fuel hose which wasn't available in one piece that was long enough, so it now has a joint in it!
But it don't leak.

Alan

[Robsey]

I think there are a few threads that report that the old rubber hoses do not last long with modern ethanol-rich unleaded fuels.

My last major leak was a split and perished rubber hose on the return pipe near to the rear off-side wheel arch.
(Return rigid pipe to fuel tank hose.)

[Robsey]

I think there are a few threads that report that the old rubber hoses do not last long with modern ethanol-rich unleaded fuels.

My last major leak was a split and perished rubber hose on the return pipe near to the rear off-side wheel arch.
(Return rigid pipe to fuel tank hose.)

[cavalier1990]

I have a 1.8 expression with 53k miles on the clock. I have recently noticed my fuel economy hit the deck to the point of it now being unreasonable to run. It is important to note that i do understand that these are known for their below average poor fuel economy. I am told that the car smells like fuel when running about. Could it be running rich?

Does anyone have any suggestions as to what maybe causing this sudden increase in fuel consumption?

Thanks so much in advance.

Are the plugs sooting up? If it's the engine using way too much fuel then it should show on the plugs, should be a light beige/brown colour, anything darker or black sooty, likely a problem with engine/sensors, if not you've likely got a fuel leak. I take it it's the electronic type carb? If so check manifold gasket for leaks, it's quite common and since your car is low mileage, but built in the 90s some point, then the gasket is likely dried out and broken. While there check all the usual suspects like the vacuum pipes, air intake, dizzy cap etc.