Bringing the car out of conservation

[Oldsmobile Desperado]

Had the car parked in an open garage in California (mild weather changes, some showers, nothing extreme) for a year. Flushed oil & changed air filter. What else should be done normally to switch to active driving.

1 thing I noticed already, that my mpg dove from 21MPG to 18MPG (I have a 4litre 1988 car).

The sparks were changed less than 5K miles ago.

What are the usual causes of such mileage dive? Several years ago it already went down from 24MPG to 21MPG.

 

[GOT2B GM]

Burn off the old tank of gas and get some fresh stuff in there.

[Crazy K]

after the new tank of gas... change the fuel filter.

 

oxygen sensor ever been replaced?

 

 

[Oldsmobile Desperado]

after the new tank of gas... change the fuel filter.

 

oxygen sensor ever been replaced?

 

 

 

Yes, I don't have an exact record, but O2 was replaced around ~40K miles ago, when lean exhaust code was showing up.

 

The car acts a bit like the cat is clogged - exhausts in small coughs during acceleration from idle sometimes. The converter was changed also around ~40K miles ago or so...

 

I don't have any codes though. Does anyone know what a "lambda" is?

 

[Spectrum]

Lambda is a greek letter (Λ).

[Oldsmobile Desperado]

Lambda is a greek letter (Λ).

 

Oh, it looks like lambda probe is just a synonym for the O2 sensor.

I'm reading conflicting accounts that these have to be replaced every 30-50K miles vs that "I've never replaced my O2 in more than 120K".

I do recall replacing it in the past w/out any impact on the MPG value though.

[digitaloutsider]

Curiously, what car is this?

[Roadzombie]

I agree with the first couple people who replied here...burn off the old gas and replace the filter. I'll be going thru the same thing here in the next week or so. Picked up a 90CS thats been stored in a garage for the last 4 or 5 years...with a full tank of gas. Got it running yesterday, but idle smoothness is not a strong point at the moment. On the upside, it has less than 60k miles on it and a folder full of PM receipts. This was my grandparent's car and I know roughly what kinda MPG they used to get on it...I'll keep ya posted on how mine is doing as well. Not expecting too much as the exhaust does smell quite rich (I let it idle in the driveway for a good hour...rodent/stray cat check).

 

I did have to laugh, however. The car has always been garage kept...kept immaculate as hell (weekly or better car wash/wax)...and yet there are spots where the paint is still peeling up. Hooray for GM paint...bastards.

[94CutlassSLCoupe]

which engine does it have? 3.1?

[Oldsmobile Desperado]

which engine does it have? 3.1?

 

3.8

Still the whole levelled drops in MPG are a bit mysterious to me.

I already burnt several gas tanks. So now it's a matter of changing the fuel filter and looking into the lambda probe & cat?