VS Ecotec Poor Fuel Economy
I have read most of the relevant posts but still can't isolate the cause for such poor fuel economy. I drive slower then a granny. Use Prem fuel, tyres are pumped high. Done 170,000.
I only get 260-300 ks per tank of normal inner city driving, even after all the below work done! No error codes are present now or before all the below work. One mechanic did indicate that one of the cylinder banks seems to be running rich due to the plugs on that side looking 'blacker' than the other side.
The engine went through a recent major cleaning and repair exercise including ;
- new fuel pump (on the way out) and filter, hoses checked all good.
- new fuel pressure regulator, injectors removed and professionally cleaned, no fuel smell or leaks detected.
- new o2 sensors, wires cut and earthed at the ECU (as per the howto).
- new IAC and checked TPS.
- New Air Temp Sensor and cleaned MAF with proper MAF cleaner (these two things fixed my previous rough idle).
- New Coolant Temp sensor (fixed my high temp reading), Temp sender, thermostat and radiator cap.
- New CASs, both Cam (after breaking down) and Crank.
- New plugs and leads although one bank of plugs is blacker than the other side.
- Removed Coils, DFI and cleaned (The DFI plate was slightly corroded).
- Compression checked and all cylinders within normal range, No excessive oil consumption although exhaust tip is black.
- Plenum, TB, PCM and intake manifold removed and cleaned (yes inside was filthy)......new gaskets.
- Plenum, TB and canister vacuum tubes checked.
Yes the car now drives like a dream and really smooth after all this work, but still drinks way too much.
Last edited by primo; 24-05-2011 at 10:19 PM.
You can try servicing the auto trans if its auto.I found these cars get better economy when they are kept serviced properly,including the auto transmission filter and fluid.You can service it yourself easily enough,you only have to buy a filter service kit for the trans and 5 litres of dexron 3 auto trans fluid,about $50 for both at places like supercheap etc.Another thing you can check is the rear brake calipers,these calipers are known for seizing up where they slide on the slide pins on the calipers,this can cause the pads to slightly drag on the discs which can increase fuel consumption..
Searching for the billion
primo, thats some really crappy economy you are getting but you have not said what type of driving you are doing. Also when was the last time you went on a long drive, of say 400 km highway stretch and what economy did it return then ? ( OK so if you live in tamworth then i guess you aint doing much city driving ). your not just driving this 2k's a day to the shops and back are you ?
Only thing left to do is either change your engine - it could be a dud, OR the easier option is change your memcal card or whatever its called to another standard one that you know gets better economy.
best ive ever gotten was 350kms city driving. hence i have high ratio rockers, chip, aftermarket air intake and all that fuel chewing sh#t. is your car completely stock or has some performance mods? i thought mine was bad LOL
Whats your consumption in L/100 km? 'Ks per tank' is a really bad way to measure consumption since most people dont run them till empty or anywhere close. You might have 20 litres left when you refill and be getting 13l/100 or something which is not bad for city driving
I have an Exec. How do i manually calculate L/100 km?
EDIT:
Found this - L/100km Fuel Consumption Calculator / L/100 km Fuel Efficiency ( litres per 100 km) Calculate Liters/100 km Calculation Chart / Table
So what i have to do is wait till the tank is dead empty.
Fill her up.
Wait till the tank is dead empty again.
Calculate 1 l/100 km = 1.0 × 10-8 m2 or use the above link.
Once again, that poses the risk of "how do i know when my tank is empty and doesnt have about 20 litres left?"
Still will not generate an accurate result.
What are you serious champ? How do you figure you need a dead empty tank to work out fuel economy? And why is it innacurate? I didnt think this requires explanation but here goesOriginally Posted by Krilnik
1).You fill up your tank, reset your odometer.
2). Drive around until you decide its time to refill
3). Go to a servo and fill up your tank.
4). Read the display on the fuel pump that tells you how much fuel you have put in. Lets assume youve put in 46L
5). Check how many kilometers your odometer says you drove since last refill. Lets assume you've traveled 412 kilometers
6). Get out your phone and enter the calculator program or use your brain if your that way inclined
7). Type in 46/412. Then times by 100
For this example it gives 11.17L/100kms. That number is your fuel economy
^^ exactly right.You can tell how much fuel is left in the tank when you refill it.The VS sedan petrol tank holds 63 litres,if it takes 55 litres to fill it,then there was 8 litres left in the tank..
The VS fuel tank capacities are-
Sedan =63 litres.
Wagon =68 litres.
Statesman =75 litres.
Utilitity =64 litres.
Try changing you thermostat as if your car is running too cold it will be running on choke cycle and use too much fuel. Mine was doing the same thing until I changed my thermostat....also check you temp sender as that could do the same thing too...
Bazza
pls read my original post on what I have already replaced.
have you got any exhaust upgrades mate or bigger wheels and tyres ?? ( i know you said you have checked air pressures ) but if you have for example 20" rims your cars working harder to turn them big boys and maybe your cat is blocked restricting flow giving your computer shit readings so it doesnt know to put it more or take etc...or maybe you have no mufflers and ur fuel is going straight out the pipe ?? just some suggestions you havent mentioned - my old lady has a vs calais and was averaging 450km's around town , i slapped some 19"s and a 2 1/2" catback system on it straight threw no mufflers and shes dropped to 350km 400 full nursing - just showing that it makes quite a difference - Also do u live in a hilly area ? could take a bit more out of the bad girl ? ( #### 300km's a tank id be f***ing that off if i couldnt get it sorted especially given the ammount u have put into it just trying 2 cure this problem lol ) - each to their own -
maybe just replace your charcoal cannister for the sake of it being a cheap replacement see if that helps too - u said u checked pipes but maybe its internal...can also be cleaned if u dont wana spend much more cash
I just saw that youve had the injectors professionally cleaned/tested etc.This could be your problem also,when I went to find out about getting my VSV6 injectors cleaned,the EFI places around here wanted around $150 to clean and rebuild and flow test the old injectors,I asked these places about some brand new injectors that were on ebay fairly cheap,and most of the EFI places said that thats what theyd be doing instead of having the old ones cleaned,they said that even when old injectors are cleaned,rebuilt and tested etc,theyll never flow as good as new injectors will,this is why I decided to go with brand new ones.Heres the ones I fitted in the link below.They made a huge difference to how it started and ran,and to the fuel economy,just all round running way better..so it might be worth keeping this in mind if you dont find anything wrong anywhere else...
---COMMODORE NEW FUEL INJECTORS VN VP VR VS VT VX VY SAVE | eBay---
no the car and everything in it, outside it, under it, on it, over it, attached to it, near it is all stock :-)
not a bad idea but how does one know if the canister is on the way out?
well when I picked them up, the guy said that they actually weren't bad at all but he still refurbished them. He said they first run a test on them side by side, then put them in a ultrasonic or sonic? bath, new o rings and then retested again. He said if they where crap he would of recommended to sell me new ones.
what I love the best is how the run of the mill mechanics can't seem to isolate these types of problems, leaving us poor owners scratching our heads.
When I had my recent rough idle problems, three different mechanics couldn't find the cause leaving me to try and fix by process of elimination, cost me a bit in the end replacing individual parts.......but I still fixed it !
I went to see a few different EFI places to try to get a wide opinion of whats really best,and a couple of them said that most shops will recommend reco ing them instead of renewing them as theres more in it for them.These two places both recommended that I get the new ones,even though they are a cheap brand injector, and suggested that they wont probably last as long as bosch brand injectors,and I just probably wouldnt get 10 years out of them like the bosch brand ones..I will have replaced them again by then,so thats no problem,and thats what I did, I went with the new ones and Ive got excellent results so far from them.Also Ive had mates who have had their injectors cleaned and the end results werent really that noticable unless the injectors were really worn out or blocked up..
Knackers, i didn't read your first post properly. I only switched onto your point afterwards.
Anyway, 15.19L/100K's:
- Stop/start driving ONLY in peak hour
- Car never gets driven outside of peak hour morning and afternoons
- I hit a freeway for about 2 k's each morning
- Apart from that its crawling through traffic. Coupla instances where i may travel at 60kph.
Fellas, does 15.19L/100K's sound right for those conditions?
I'm buying a can of CRC MAF cleaner this weekend and will give the MAF a clean.
Sorry to hijack your thread Primo but im going to bookmark this thread and defiantly try a few things you've mentioned in your first post...thanks.
Also, please keep us updated if you find a solution to your poor mileage.
Doesn't drive like this
Mine does ~8L/100km on the highway, but does ~14L/100km in the sort of driving you describe (a little higher with the A/C on). Which I think translated into about 350km when the fuel light came on. So I don't think that 15L/100km is extraordinarily high.
In my opinion, anyone serious about chasing down fuel economy problems needs to check the the engine parameters with a ScanTool or an ALDL cable and a laptop, otherwise you are just guessing. Your sensors may well need replacing, but you need to look at what the ECU is interpreting from these sensors to judge whether your wiring or ECU is dodge as well. Just my 2 cents.
When I first got my car I replaced the O2 sensors and it improved the fuel efficiency of highway driving, but did very little for the round town and short trips. Turned out that the O2 sensor heater earthing problem was preventing the car from enter closed loop mode as the ECU couldn't tell if the O2 sensors were ready. Quite randomly when that sensor got hot it would register a spurious signal and trick the ECU into thinking it was ok. I couldn't get this information without the ALDL cable, as there were no fault codes logged. I could have cut wires and replaced sensors and spent a lot of time and money, and I am glad I used the ALDL cable. While I realise the OP has attempted to fix the heater earth issue by cutting wires, there still could be another sensor sending odd results due to another wiring issue.
Hey Brett, are you sure the sedan tank is 63L? I have 59L in my head.
Last edited by aceventura; 26-05-2011 at 09:18 PM.
A Memcal a Day Keeps..
have you had a scantool or laptop on it to see what's it actually doing? seems like your just wasting money for nothing trying to guess.
The first thing to check, as many members suggest, is actual fuel consumption. The next is to check spark plugs condition, as long as the spark plugs show good color then you don't need to give a sh it about the economy.
Yep, definitely 63 litres for the standard sedan tanks...
If someone could come up with a solution for this it would be great as i am having the exact same problem and have been for around 6 months and im just about to give up with replacing fine parts.
ODO: 178xxxkm's
Yep I checked the fuel consumption...............it sucks! :-)
The plugs on one bank are blacker than the other side...........meaning that side is running rich??
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