VS Ute - Bad On Fuel - Ideas Why?? 300km A Tank

[vsute97]

Hi Folks, I have a VS V6 Ute which potentially has kigh kms (around 250,000) but seems to be mechanically sound. Does anyone have any ideas why my ute is only getting 300kms out of a 50 litre tank?. I have changed the oil, oil filter, fuel filter, spark plugs, run injector cleaner through the motor and checked the air cleaner element. The Transmission also appears to be very strong (automatic) and operating as it should. Does anyone have any ideas in what I could do to fix this as im sure I should be getting at least 450km a tank and the 300km a tank was on a long run! The next thing I thought of was maybe a tune? If anyone could help please shoot your ideas through! Cheers.

[tezza]

Any error codes coming up? Might need the O2 sensors checked / replaced.

[zskinner]

ive got a vp v6 buick engine so your ecotec may not have these, but when i was getting shit fuel economy in my vp i changed the coolant temperature sensor, the MAT sensor and the oxygen sensor (as tezza said above), and my fuel economy got way way better, may be worth looking in to......... good luck bud

[vsute97]

have not checked any codes as yet but will do, should be getting more than 300km a tank surely?? cheers! =P

[edals]

Yes, You should be getting almost 700kms on country Road, Check the codes, if not i would start with Oxy sensors

[badboyblair]

o2 sensor man and your aifflow metre and intake system check injectors thats all i can think of mate i had the same thing happen on my vz i had the o2 sensor and air flow metre replaced and put a cool air intake on it lots better and more power

[Jonnii]

Does it have a bad fuel smell in cabin too? Ive jsut found the problem to my bad fuel economy and its a blocked fuel rail/return line. I had mine serviced they tried to blow it out with compressed air but its blocked good. Maybe get yours checked as well

[vsute97]

No bad fuel smell in the cabin but I did the fault code check and it came up with code 12 and 76, I know 12 is a normal code but the 76 is - air/fuel ratio variation between left and right banks. How can this be fixed? cheers for the help

[tezza]

Reset the ECU and see if the code returns first.

My Gregory manual says the following:

- possible causes are blocked injectors, faulty spark plugs or leaking exhaust or inlet manifolds
- check fuel pressure, ignition system and compression
- run engine to normal temp and then run it at 1600-1800 rpm for two minutes.
- with the engine idling, measure the voltage at the ECU terminal D13 (RH oxygen sensor) and D15 (LH oxygen sensor). The voltage should quickly fluctuate between 0.1 and 1.0 volt.
- if the voltage does not fluctuate, replace the relevant sensor.

[Brett_jjj]

Also make sure the ECU and 02 sensor earths are clean and tight.The earth points are on the engine on the heater pipe connector on the drivers side front of the engine,one at the rear of the passenger side head,and theres another body earth near the battery under the bonnet.It doesnt hurt to run another earth wire from the engine to the battery negetive terminal,and another earth wire from the negetive battery terminal to the body.

[hako]

300km from a tank with mixed driving is not real bad....some get less and some will get more. Unless you have other faults like hard starting, misfiring etc, you may be wasting your dough replacing parts for no other reason than they 'may' increase your economy.

[tezza]

300kms is a bit dismal even for Sydney traffic I'd expect atleast 450-500kms on a freeway run.
But it also depends on how your measuring the fuel usage. 300kms with 50 litres is 16.7l/100kms which is a tad high for freeway. Around the city, I'd probably think the ecotec would get about 12-14l/100kms and then 10-12l/100kms on freeway.

My ute (manual) gets about 12-13l/100kms in Sydney traffic. When I did a run up the freeway it was averaging about 10l/100kms.

[Brett_jjj]

I can get around 9-11 L/100km around town,and around 6-8 L/100 km on the highway from my VS V6 sedan..I only use 98 octane fuels.Its worse than this though when on normal 91 unleaded.

[greenacc]

I agree, when an ecotec is running right you should get 600k to a tank on the highway, supposing you aint carrying a tonne of bricks in the back ?
How's the compression and oil usage ? could just be getting old.

[ephect]

generally 3 things affect fuel economy

o2 sensors! -
MAF sensor -
ECU coolant temp sensor.

because ur getting code 76 points to o2 are shot or one of the 2. this how-to may be of use How To: Fix the VS V6 4 Wire O2 sensor earth problem – Known Holden Problem

[db_notso]

9/10 time oxygen sensors dier at about 180,000kms for HEATED type more than two wire's comming off it
for non heated two wire or one wire for some old bastardss out there 100,000km's
replace your oxygen sensors
DONT OVER TIGHTEN THEM
take your battery negative off for 5 minutes then reconnect with car cold and let idle until hot then drive ten minutes fill it up at the servo and recheck your fuel usage in km's

[MADDNE33]

i have a series 3 manual vs ute and can get 430 out of a tank without any freeway driving. i have heard of people cleaning the top of there plenum ( intake manifold ) and getting better fuel economy.

[db_notso]

little known too most the biggest killer of fuel economy is
too lower tyre pressures
too much load in the back and or wind resistance
or poor engine tune

[The1]

400-450 is what you should get for a well running vs in town and 600 on the highway, anything less than this could be 02 sensors, ECT sensor and Dirty or faulty MAF sensor can also affect fuel economy. Checking error codes as above would be first move, has the engine got any mods done to it or is the car completely stock?

[godatfourdigital]

I brought my ute last Friday, v6 5speed, 2000 model, filled it up on Friday, and I'm up to 570km and the fuel gauge is on the 2nd last line from the bottom, that's half highway, half town/ traffic driving. I'll be happy if I make it to 650km. Which it looks like will.

[slutvs]

hey mate i have a vs ute too and im getting bout the same, maybe 350-400 if i drive it "calm" and dont rev the guts out of it. i found that when i had a performance chip and other little stuff put in and had the car tuned it chewed it a bit more. used to get about 400 atleast. no performance mods that might wanna chew the fuel? plus im driving in traffic all day so doesnt help the situation haha. also what fuel you putting in it?

[vsute97]

The ute is completely stock apart from a lukey catback exhaust but its also automatic which may not help the situation, at idle i can notice a slight twitchy engine vibration while
at the lights in town could that be part of it? i was going to start with the oxygen sensors to see if that helped as thats what most of you have said, thanks for the help folks! =P

[The1]

Have you checked for error codes yet? Buy 2 O2 sensors of the same brand and model so both match, they will be either 2 wire or 4 wire, just have a look, buy Bosch or Delphi is best. Stock holden sensors are Delphi.

[vsute97]

yes mate it came up with 12 which is system ok and 76 which is air/fuel ratio variation between left and right banks?? could that mean a dud oxy sensor?? cheers

[greenacc]

I was once told that that code could be caused by a faulty fuel pressure reg. If anyone knows better feel free to clear that up. Oxy sensors are an obvious possiblity. Otherwise you could have an air leak somewhere or burning lots of oil on one bank ?