Volvo 1988 740 GLE Low gas mileage.

I have a 1988 Volvo 740 GLE Wagon. It runs very rich. It does something
like 18mpg or so in the city and around 23mpg or so on the highway.

I changed the O2 sensor, the spark plugs are relatively new, the gas
pressure regulator, the fuel filter. I have tried additives to clean
injector but all this just went in vein.

Does anyone have any clues as what to investigate? What might be the
problem?
I like the car very much and hope that I can drive more often but I
only try to take it in longer trips because of its bad fuel economy.

The car has 150Kmiles on it.

Any help will be very much appreciated.

 

Have you checked the AMM / MAF?

 

I have changed the Air Mas Meter since the previous one was busted.

What is MAF? (Excuse my ignorance).

 

I am investigating a similar matter. My 1987 740 GLE was getting about
27-28 mpg until recently when I fixed the A/C. My next tank of gas
lasted only about 200 miles in the city. It might be just a one-time
thing, maybe someone swiped a few gallons, but I'll be keeping an eye

 

I have a similar problem with my '95 940 (nonturbo). The BEST I get around town
is 18-19 miles per gallon. That is with AC. Not using it is not an option in my
part of the US. The few months a year (about 3) I don't use the AC mileage only
goes up 1-2 mpg.

 

Thats interesting; I get about 19 city and 22 highway and didn't
realize that was low for the 740 GLE. Anything you recommend I check?

 

MAF is Mass Air Flow Sensor. This part of the Air Mass Meter. So, are
you suggesting that the sensor inside it is probably not working
properly? By the looks of it, it has that thin wire connected when I
hold it to light while the older one was not. So, may be I should check
it.

Do you think it is worth it to get to a dealer to get me detailed
diagnostics?
How much would they get probably? Does anyone have any estimates?
Or, I just get it to someone to do Fuel Injectors induction?


I know of a friend's 1989 740s GL doing 27-29mpg on the highway and
definitely better than 18mpg in the city.

 

I have a 1990 volvo 740 GLE 16V. The insert that originally came with
my car says that it gets 18mpg city and 24mpg highway. For a car that
weighs almost four thousand pounds, that does not seem to bad. I
usually buy $15 dollars of gas, which makes me feel better because I
don't have to give so much of my money, and then drive for 115 miles.

 

hi folks....

Your mileage is at the low end of the range I'd advise my customers to
accept but there are many variables. Automatic trans....less mpg,
A/C......less mpg, deferred maintenance....less mpg.

If you are truly running rich pull the dipstick and smell the oil. Oil
contaminated with excess fuel will have an acrid odor. Excess fuel
vapor from a rich condition will also throw off the O2 sensor, causing
it to adjust too lean leading to incomplete combustion and lower fuel
efficiency. Possibly change oil combined with the O2 sensor.

Mass air flow problem less likely especially if it runs reasonably well
otherwise. EXCEPT, we purchased [once only] several reman MAFs from an
otherwise reputable firm which had faulty ambient temperature circuits.
They started and ran just fine but had poor mileage. Which leads to....

Coolant temperature sensor issues. Think choke. A CTS can degrade and
convince the ECM that engine temp is 20 or 30 degrees less than actual.
Just like a partially stuck choke will degrade mileage so too will a
CTS out of range.

Should you take it to a dealer or specialist ? I'm biased, of course,
but generally understanding the electronic systems and strategies are
beyond the knowledge of an otherwise skilled home mechanic. I have
numerous customers perfectly capable of doing brakes, timing belts,
clutches, etc. who [wisely, in my estimation] put electrical/electronic
management systems in other hands.

pat hayes
preferred fleet
medford, oregon

 

I've owned my car for about 6 months now, and it's spent most of that
time at a mechanics or on jack stands while it was being restored.

In the last 2 months I've made 10-15 mile trips, but tonight I made a
90 mile run. I think the mpg is back to around 25 on the highway, with
the A/C running wide open.

That's the 8v 4-cylinder non-turbo, finely tuned.

I don't know what caused the short run mpg's last week, maybe it
evaporated in the 110F heat or some kids swiped some gas.

 

On 11 Aug 2006 15:09:25 -0700,

That car should about 2900 pounds (~ 1300 kg).

 

How do you know the car runs very rich.

 

Wrong, owners manual says 3965 lps/1800kg for my 16 valve.

 

Wrong, owners manual says 3965 lps/1800kg for my 16 valve.[/QUOTE]

I think that figure is maximum allowed weight of the car including
passengers, fuel, cargo. Just the car itself weighs around 1300 kg, as
far as I know.

 

I think that figure is maximum allowed weight of the car including
passengers, fuel, cargo. Just the car itself weighs around 1300 kg, as
far as I know.
[/QUOTE]


Sounds about right, most 200 and 700 series are 2900-3300 lbs empty or
around 4,000 with a full load.

 

I have no idea what is the exact term means but this is the expression
of an at-home mechanic that I know.

 

I have no idea what the exact term means but this is the expression of
an at-home mechanic that I know.

 

I have a 1993 Volvo 940 (non-turbo) with around 136,000 miles, B230F
engine. With the air conditioning constantly running, I get 18.6 MPG.
Without air, I get 20.5 MPG. On the highways (averaging 75-80 MPH) I'm
lucky if I get it up to 21 MPG.

It leaks about a quarter-sized drop of oil each night, not sure if this
is a problem or not.

 

I am Canadian where we purchase gasoline by the liter (close to a quart)
which is an idea that I am not proud of but that's Government for ya!
Currently we are paying $1.31 per liter for Premium with an octane rating of
only 93. At 4.5460 liters per Imperial Gallon that comes to $5.96 per
Imperial Gallon.

I have an American Volvo so the odometer reads in Miles. Currently it has
112,000 miles on the clock and is a 94 940 turbo wagon with an automatic non
lock-up transmission.

Been keeping a track on the mileage lately and the current results over the
past 10 weeks are a low of 19.63 MPG city and a high of 29.86 MPG Highway
averaging 55 to 60 MPH on the highway.(no air conditioning and I do have
roof racks).

Please note that figures are based upon an Imperial Gallon, the unit by
which we use to purchase gasoline before the Government had a Vasectomy.

According to some of the posts here I am doing quite well but I still wish I
could do just a little better. I wonder if some of the folks here who are
not doing so well with their gas mileage are leaving their ventilation
selector set to defrost all the time where the air conditioning is on by
default or are driving down the highway with their windows open (excess
drag).

 

I wish it'd be as cheap here as well. Currently the price of 95
octane (RON, I think) is 1,35 EUR (1,75 USD) per litre. And that's the
cheapest octane rating.

???

Litre is an SI unit which is cool. Gallon is funny as such already,
yet there are more than one definitions. Comparing MPG figures
requires conversion from one gallon to the other...

Here in Finland (as most of Europe I guess) the mileage is measured as
litres per 100 km.

I have a 240 sedan with manual transmission and B200F. On summer I get
about 7,7 l/100 km (on highway or smaller roads on countryside at 85
to 100 km/h, 50 to 62 mph, a bit in city as well) or 30,7 MPG (US
gallons).