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Hey Folks,
Been looking though the archives and googling regarding fuel consumption of the 760 GLE with V6 NA engine. There isn't that much out there.
I've had the car for a month now and the PO told me it was a gas guzzler (he was using 15 to 20l per 100km!), but I dismissed that because he was VERY lead footed (practically lost his licence because of speeding).
The car runs well and powerfully and I have no problem getting it past 150Km/h but if I drive it at more conservative speeds (tested over 150km at approximately 100km/h), I barely get better than 13l/100. With the weight of the car and I would have expected that figure to get closer to 11. What do you think I am doing wrong, or what could be the cause of this thirst for gas? Or is it close to normal for this car? Any way to improve that?
The engine is two years old and running synthetic oil (5W50) and it feels very powerful. It doesn't seem to burn any oil. The oil is quite fresh, the air filter is almost new, the tires are inflated close to the upper limit and the AC was off when tested. I do get a noticeable gas vapour odour in the cabin when it sits for an extended amount of time (maybe corroded gas vapour venting pipe in the trunk?). Otherwise it idles correctly and performs extremely well warm or cold and it goes readily into overdrive (auto transmission). The catalytic converter was replaced two years ago and so was the O2 sensor. The AMM was replaced about three years ago. The engine starts instantly with no stumbing or hesitaion. The distributor, rotor, cap and spark plug wires were replaced last year. The fuel pumps are new from two months ago. There is no noticeable leak or gas smell coming from the car when I park it. It does seem to need some sort of alignment (it oversteers noticeably, especially when hitting bumps in the middle of cornering at high speed), the tires are quite worn and it seesm it would benefit from a valve adjustment (its first on that engine).
Any help would be gratefully accepted!
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Hey folks,
So I found at least one of the causes of my high fuel consumption: a dripping hose when the engine is running. Unfortunately it is not at the trunk access panel like I hoped but rather beside it, and more difficult to access. There is a 1" or so hose that is dripping, drip, drip, drip... That hose is connected to a tube close to the top of the tank that appears rusted :¬(
The second culprit appears to be fuel delivery related. When the engine has warmed up, the idle hunts AND the exhaust puffs clouds of black smoke (running rich). I took the FPR return hose out into a gallon jug and it took less than a minute to fill!!! So I presume the FPR must be running right. The fact that it hunts tells me the O2 sensor must be working alright.
Any ideas where to look from here? I have to get this thing going tomorrow, as my truck batteries suddenly died yesterday after 10 years of faithful service and I need to get new batteries for my truck, so in effect I am stuck with no vehicles at this point.
TIA for your help!
Chris
'87 760 GLE
'83 BJ60 Land Cruiser
BTW, I wonder was this post is not showing back at the current post level?
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well i have an 89 with 224 000kms and has been very well maintained.I get in the city about 15l/100km and on the highway i got about 9.5l/100km.i tested this this summer going to the london show.Did montreal-missisauga ,about 610 km and i filled up 57 liters.This was cruising at 120 the whole way with about 15 minutes of traffic.
--
Costa,740 tic 90' 433000kms, 760gle 89' 222000kms
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Hello Chris:
I seem to recall that my '89 760GLE w/B280F came with the window sticker that included EPA fuel economy ratings. My memory is a little fuzzy, but I seem to recall 17mpg city and 24 mpg highway. Whether or not your '87 is similar depends on build date. I believe Volvo switched from the B28F to the B280F in 09/86. The B28 is a dramatically different powerplant-- mechanically injected, very different intake and ignition system.
For what it's worth, my 760 was sold first in Arizona-- there was a "gas guzzler" tax that the original purchaser had to pay. That should tell you something! I NEVER saw 29mpg ever-- I keep my cars in good tune and I don't have a particularly heavy right foot...
Fuel odors on mine were caused by a faulty fuel pressure regulator. A cheap and easy fix, with a huge mileage improvement too...
--
Herb Goltz, London, Ontario, Canada '92 245 w/109K mi
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"Hello Chris:"
"I seem to recall that my '89 760GLE w/B280F came with the window sticker that included EPA fuel economy ratings. My memory is a little fuzzy, but I seem to recall 17mpg city and 24 mpg highway. Whether or not your '87 is similar depends on build date. I believe Volvo switched from the B28F to the B280F in 09/86 "
Yes it is indeed a B280F, 1987. However teh engive ahs been replaced twice. This one is a factory rebuilt. But I doubt they would have installed a B28F beascsue of the differences in the two engine generations:
"The B28 is a dramatically different powerplant-- mechanically injected, very different intake and ignition system."
"I NEVER saw 29mpg ever-- I keep my cars in good tune and I don't have a particularly heavy right foot..."
Well we should ask what deejay's daughter is doing so well to get that kind of mileage!
"Fuel odors on mine were caused by a faulty fuel pressure regulator. A cheap and easy fix, with a huge mileage improvement too..."
Hey that is very encouraging as it is exactly how mine behaves... Gas fumes in the cabin when it's been sitting (could also indicate a problem with vapours venting instead of being stored). If that was the problem it would definitely make my day :¬)
Thank you for your inmput :¬)
Chris
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Some 760's have two fuel tanks; an 'upper' one and a 'lower' one. They are linked by a crappy rubber pipe which is known to fail. The one on my 760 failed and resulted in fumes inside the car and dreadful fuel consumption. Might be worth checking if the other recommendations don't yield a solution.
I recently did a full rebuild on my B28 and now get an average of 23 mpg (imperial gallons). More on a decent run.
Also, I'll assume that the tranny is engaging overdrive ok? If it isn't fuel consumption can suffer.
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"Some 760's have two fuel tanks; an 'upper' one and a 'lower' one. They are linked by a crappy rubber pipe which is known to fail. The one on my 760 failed and resulted in fumes inside the car and dreadful fuel consumption. Might be worth checking if the other recommendations don't yield a solution."
Great to know! I've got so much to learn about this car and you guys are so kind to share :¬)
"I recently did a full rebuild on my B28 and now get an average of 23 mpg (imperial gallons). More on a decent run."
That's very encouraging, as the B280F engine is more recent so in theory should do even better! Also, it's only a few years old and it doesn't appear to burn any oil and it has (subjectively) plenty of power... Maybe adjusted valves will help?
"Also, I'll assume that the tranny is engaging overdrive ok? If it isn't fuel consumption can suffer."
Yes it does, no problem.
Thanks for your input...
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My daughter's 760 with 189000km on the orginal V6, auto tranny, gets roughtly 29mpg highway (Imperial Gallons, not the little american ones), in average tune. I don't know what that is in L/km, but I'll bet its a whole lot more than what you are seeing.
JD
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Whoa! That's EXACTLY what I'd love to get, this is encourraging... Is that 760 with auto transmission and at what speed is it driven? It's using almost HALF the gas mine is using... Also, is this an 87 model as well, or is it a newer model with presumably 'smarter' fuel and ignition control?
Thanks for your input, it is encouraging to know it can get better (but I wonder what I'll have to do to get there!)
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My daughter's car is a 1989. The consumption was checked on a drive from Calgary to Fort St. John, a distance of some several hundred miles (8 hours)and at speeds that likley averaged 90kph (accouning for lower speeds while travelling through municipalities).
She has about 250,000km on it now, and I think she is getting more or less the same gas consumption. I was pleasantly surprised when we checked, as I had been expecting only about 23mpg.
My wife's 960 gets up to 32mpg (Imperial) on the highway with the B6304 engine. Gotta love those 6's, both V and Inline, for power! My 240 with a 4 cyl B23F doesn't get as good mileage as either one of the 6's.
JD
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That is remarkable! I can't believe there is such a huge difference between the two model years, it must be mostly tuning. I wonder how others of the same vintage are faring, though... But it's surprising because from what I've read so far, the 4s tend to be more economical. There is hope for me then?
In any case I presume, since so much stuff was replaced in the past 4 years (I'm sure quite a bit needlessly because of wrong diagnostic) that not much remains to be changed in the near future. The fuel pressure regulator OTOH has NOT been replaced during that period and the injectors have NOT been looked into either (almost every thing else has been replaced in the past 4 years according to the wad of service bills I went though the other night - can you believe, $21,000 in the past 44 months?!).
After I check the seat heater tomorrow I'll check the fuel pressure after the regulator using the jar and hose test. Maybe (probably) the injectors would also be happy with a good cleaning!!! And if I can dig up a proper spark plug socket (first time I'll use one in over 15 years!), I'll have a look at the combustion history :¬)
As for the power output and smothness of the engine under acceleration, I must admit I am quite pleased. Now if only we could get a system like there is on the Chrysler 300C, where half the cylinders of the engine get shut down during cruising to allow incredibly high gas mileage... Hmmm!
Best Reagrds,
Chris
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posted by
someone claiming to be swede4
on
Wed Oct 13 03:29 CST 2004 [ RELATED]
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The jar and hose test will only tell if you have good flow. You need to test the pressure with a gauge to verify that it is within specified range and not too high.
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"The jar and hose test will only tell if you have good flow. You need to test the pressure with a gauge to verify that it is within specified range and not too high."
Yes I agree in principle but I don't have a pressure gauge and to get one I have to drive over 50 km! In any case, how much do pressure gauges cost? I haven't needed to work on a gasser in over 15 years and I thought those were expensive items.
In any case the pressure regulator was never changed on this car AFAIK so it is my pripary suspect at this time, considering I also have noticeable gas smells when I open the car after it's been parked. I'll see what happens when I finally get out in the driveway to check it out.
Thanks for your input!
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posted by
someone claiming to be swede4
on
Wed Oct 13 15:01 CST 2004 [ RELATED]
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A regular water pressure gauge (pressure is pressure, whether water or gas) from your neighborhood hardware store for about $5.99 can be used if you can connect it with hoses and a tee fitting. If it requires threaded fittings it may be more difficult to attach the gauge.
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"A regular water pressure gauge (pressure is pressure, whether water or gas) from your neighborhood hardware store for about $5.99 can be used"
Great tip! I'm sure I can dig one up from my back storage room...
:¬)
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posted by
someone claiming to be swede4
on
Tue Oct 12 16:27 CST 2004 [ RELATED]
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I would start by checking the fuel pressure to verify the regulator is OK.
For the gas vapours ,start by checking that the carbon canister and all related hoses and valves are working.
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Great hint, I'll check the regulator tomorrow :¬)
As for the vapour canister and hoses, what a tangle... I'll give it a try!
Thanks for your answer :¬)
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It is most likely that fuel pressure regulator.
Things to check at the time of replacement of it. Does the oil look funny on the dipstick at all? Even a smidge? My b280 fuel pressure regulator failed and caused the engine to run like crap at idle, but fine on the road so I back burnered the problem for a couple of weeks and low and behold the engine was making oil. Although usually only seen in big trucks (diesel) guys get the same thing. I guess the engine is getting way too much fuel at idle, startup up shutdown, thus the fuel actually you smell might be coming from the gas in the motor oil.
My exhaust, and oil dipstick both had smelled of fuel, and the dipstick showed I had accumelated over a quart of the shit. Had to change the oil 2x to try and flush it all out after replacing the stupid fuel pressure regulator.
Also the car dropped to 8-10 mpg in the 2 weeks I kept driving it.
So good luck with that and don't delay the replacement.
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