[SSSIERA]

i have somthing wrong BIG time with the sierras fuel economy. so im just gona throw all the info up here and hope to god some one can help me!


ive kept the last two recipts from fueling up. atm the car is being drive fark all

on the 17/9/11 i have recorded 20 litres to fill at 342828km with 91 octane fuel i think (well it cost 1.495 a litre)
this is pushing my memmory alot but i belive that at that point the guage was reading empty.

then today the 6/11/11 it got 16.911 litres of 91 octaine to fill. now the only reason i say to fill is because today it clicked four times in a row b4 dad pulled the nosel out (i dont know what sierra tanks are like but is it possible that it wasnt full). the guage had moved from here.


to HERE



after fueling up dad and i went and did a bit of a drive a bit of highway driving then some crawling around looking in verge side pickups for an hour or so. then drove home. sitting on the lawn now (reasonably flat and level) its reading



speedo now reads 342950

the sierra on the first refuel still had the wrong jetting in it at that point. it was then driven directly to my mates house about 20mins of highway (80-100kmh speeds)driving away he then replaced the jet in the primary to a 125 (idk what was in it b4) dad then drove it home a week later, the same way probably a little more agressivly. and then a little bit of local driving (talken an hour round town max) b4 i did the latest fuel up.

this if messing with my head and i am having one of those fuck the heep of shit suzuki of and buy a corolla days. was all happy coz the seats were sorted and look awsome and now ive found another problem. u take one of the list of things to do and add 3 to it.

if anyone should be kind enough to help me out. it would be greatly apreciated.

[Rusho]

Take little notice of your fuel gauge level. Sierra's are bad for incorrect reading. Steve has a fix in the tech section. Going by your figures you would get around 300km's to a tank. Not bad, not fantastic, spot on par for the course really.

[Rusho]

Here is the sender fix

http://www.auszookers.com/index.php?nam ... pic&t=4140

[SSSIERA]

Rusho wrote:

Take little notice of your fuel gauge level. Sierra's are bad for incorrect reading. Steve has a fix in the tech section. Going by your figures you would get around 300km's to a tank. Not bad, not fantastic, spot on par for the course really.

but if it take note of the paper results, then im getting 17liters to the 100km

[royce]

so we know now how many km you started at
we know know how much fuel you put in
we know how many km when you got home

your numbers arent consistent, we need to know how many km when you filled up the 16.9 litres, not the 324950 at home

we also need to know tyre size

but fix your gauge first, try cleaning the earth wire from the top of the tank to teh earth point on the chassis

[SSSIERA]

royce wrote:

so we know now how many km you started at
we know know how much fuel you put in
we know how many km when you got home

your numbers arent consistent, we need to know how many km when you filled up the 16.9 litres, not the 324950 at home

we also need to know tyre size

but fix your gauge first, try cleaning the earth wire from the top of the tank to teh earth point on the chassis

ARRGGHH sorry, im pretty pissed of, ill try again

first fuel up b4 new jets
342828kms and it got 20 liters (have the recipt)

second fuel up (todays one. first since new jets)
was at 342915kms and got 17 litres

[royce]

yeah thats ok for what you were doing, worry about it when its full and you can go do a few hours sustained above 60km/hr

[Rusho]

113 km's traveled / 17 litres of fuel used = 6.65 km's/litre

6.65 km's X 40 litres to a full tank = 266km's to a tank.

I'm lucky to get 260 to a 35 litre tank with 6.5 reduction gears and 31's

[SSSIERA]

Rusho wrote:

113 km's traveled / 17 litres of fuel used = 6.65 km's/litre

6.65 km's X 40 litres to a full tank = 266km's to a tank.

I'm lucky to get 260 to a 35 litre tank with 6.5 reduction gears and 31's

342915
-342828
----------
=000087

17 litres in 87kms= 5.11km/litre
i was expecting closer to ten

[joel]

Rusho wrote:

113 km's traveled / 17 litres of fuel used = 6.65 km's/litre

6.65 km's X 40 litres to a full tank = 266km's to a tank.

I'm lucky to get 260 to a 35 litre tank with 6.5 reduction gears and 31's

wow, i guess i shouldnt complain about getting 300km per 40litre wheile towing a boat full of gear with 31's and no gears.

[SSSIERA]

also i am running 205s (standard) with no gears and they are road tyres!

[SierraDan]

Don't you have a weber?

4.1 transfer, 3.9 diffs and 31's, I got 326 from full to just above the bottom line this weekend.

[SSSIERA]

royce wrote:

yeah thats ok for what you were doing, worry about it when its full and you can go do a few hours sustained above 60km/hr

im gona go fill it up so that it overflows, then drive it as much as possible and trie and go through a full tank and see how many kms i get. or im gona drain the tank then messure out 1 litre and put it back in and do laps of the block, until it runs out. and see how far it goes.

[Rusho]

joel wrote:

Rusho wrote:

113 km's traveled / 17 litres of fuel used = 6.65 km's/litre

6.65 km's X 40 litres to a full tank = 266km's to a tank.

I'm lucky to get 260 to a 35 litre tank with 6.5 reduction gears and 31's

wow, i guess i shouldnt complain about getting 300km per 40litre wheile towing a boat full of gear with 31's and no gears.

My bad...speedo is out by about 10% so maybe 280-290 km's

[Lil_Rat]

Ok so it goes
Refuel to the top, drive to mates(on wrong jetting), cars fixed, local driving for an hour(so no quicker than 70ish). Doesnt sound all that bad.

If at first results are inconsistent/not what you are expecting. Rule it as an outlyer and re-test.

[SSSIERA]

SierraDan wrote:

Don't you have a weber?

4.1 transfer, 3.9 diffs and 31's, I got 326 from full to just above the bottom line this weekend.

yes i do, and do u recon you would pull 350 out of a full tank?

[joel]

Rusho wrote:

joel wrote:

Rusho wrote:

113 km's traveled / 17 litres of fuel used = 6.65 km's/litre

6.65 km's X 40 litres to a full tank = 266km's to a tank.

I'm lucky to get 260 to a 35 litre tank with 6.5 reduction gears and 31's

wow, i guess i shouldnt complain about getting 300km per 40litre wheile towing a boat full of gear with 31's and no gears.

My bad...speedo is out by about 10% so maybe 280-290 km's

same, im out 10km @ 100km (says ive done 90km but ive done 100km on gps)
20km @200km etc etc
i hate my fuel economy, hoping when i run the efi and gears i can get at least 10km per litre, or i will have to consider putting a 1.9 diesel in it or sell it.

[SierraDan]

Yeah easy. Well the odometer would be out.. So I've done more?

[joel]

SierraDan wrote:

Yeah easy. Well the odometer would be out.. So I've done more?

you running 31's?
i find im 100m short at 1km,
when going along the hiway, those odometer markers you see, when it hits 1km, my odometer is almost rolling over to 900m,
things to note are, im running 31's with a 1litre tcase and 1litre 4.1 diffs.
so results will vary, best is to use a gps, thats what i do, strap a little garmin 401 to the steering wheel.

[skyman]

Weber's are known to suck fuel. If you can't keep your foot out of the secondary expect really really bad fuel economy.

However if it is jetted right, and you can keep your foot out of that secondary you can get almost better than stock mileage.

[xedent]

From emerald to the sunshine coast fully loaded I was getting 10L to the 100klms, 1.6efi 31's and 1l transfer, going 100 - 110

[JrZook]

skyman wrote:

Weber's are known to suck fuel. If you can't keep your foot out of the secondary expect really really bad fuel economy.

However if it is jetted right, and you can keep your foot out of that secondary you can get almost better than stock mileage.

Correcto! For an otherwise stocko sierra you should be looking at at least 10km/L cruising on the highway at ~100kph with the weber.

Dan

[skyman]

Just a weirdo FYI. When I first got my samurai it was gutless, but got insane and I mean really insane mileage.

I took a run up into the mountains, camped for two days and wheeled all weekend, I came home with half a tank and it is 35 miles of windy steep 55Mph roads 55Mph to get there. (Did I mention it was gutless).

Anyways a few weeks later I finally got around to tuning an jetting the weber that was on it. When I went to check the jets, the secondary idle was missing, there was nothing in the hole, or jet holder.

What that did was make the engine fall on it's face anytime you touched the secondary, especially under load. So I never used more than half throttle all weekend.

It took a while but the engine would get up to speed on the freeway, but it would hold 55 it just wouldn't accelerate well. So if for some weird reason you need insane mileage, or want to limit acceleration (new driver etc).Pull the secondary idle jet, it will force you to drive with economy in mind

My economy dropped by over half after I jetted the carb right.

[JrZook]

Hahhaha I wouldn't doubt that the economy would be great at 55MPH (~89KPH)

[SSSIERA]

yeah i will just have to see what the deal is with the fuel. might look at putting a warning light in for the second butterfly or somthing

[badonkadonk]

Thanks for posting this topic up. It's actually given me some reassurance about mine & the kind of mileage I'm getting from my Sierra.

My fuel gauge also likes to play silly buggers ie when tank is full gauge says empty, then kicks in to life when I've apparently got 1/3rd of a tank left. Unfortunately my tank has a couple of dings in it & at a guess I imagine I've got somewhere in the vicinity of 36-37lts of capacity- haven't wanted to run it bone dry in case its sludgeville near the pick-up. Stopping short of rebuilding the carbie, or even fiddling with the mix adjuster, the carbie was given a bit of basic love & a little adjustment. After a few weeks of evenings tinkering away on her, I took it for its highway shakedown & after completing some 1480kms over the 3 days I was almost astounded to see I was getting between 360-380kms (95-100kph) to a tank on the highway & about 280kms around the city.

A few people have raised something that I hadn't considered though, which has me reassessing- what do those numbers translate as if I'm running 16x7.50 tyres!?

[SSSIERA]

what are the chances there is a hole in the top of my fuel tank?
when i was putting the rear springs in it had quite a strong smell of fuel at times, but that would explain why its changed so much being at my mates house, he lives on the beach and the car was outside so it would have been in direct sunlight for most of the day, i recon it might be evaporating?
FML

[abclarke]

Take it out and look?

[shep]

SSSIERA wrote:

what are the chances there is a hole in the top of my fuel tank?
when i was putting the rear springs in it had quite a strong smell of fuel at times, but that would explain why its changed so much being at my mates house, he lives on the beach and the car was outside so it would have been in direct sunlight for most of the day, i recon it might be evaporating?
FML

mine leaks out from the top of the tank. fixed it by only putting in 20 liters when it is empty.

going to really fix it by putting a LWB vitara tank in, however the dodgy fix has lasted for 2 years so i am in no rush.

worst economy i have had is 50ltr to 80km.

[joel]

SSSIERA wrote:

what are the chances there is a hole in the top of my fuel tank?
when i was putting the rear springs in it had quite a strong smell of fuel at times, but that would explain why its changed so much being at my mates house, he lives on the beach and the car was outside so it would have been in direct sunlight for most of the day, i recon it might be evaporating?
FML

more than likely a breather hose fuming away mate, but drop the tank and have a look, its only 4 bolts and a clean wouldnt hurt?