Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: JuGaLi on 23 November 2008, 18:52:04
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Please Help, I have read many of the guides posted on the forums and still have a problem with my 3.0 Elite Estate with POOR MPG
I have :-
Changed HT Leads
Changed Plugs
Changed Fuel Filter
Cleaned Breathers
Cleaned Throttle Body
New Set of Second Hand Injectors
New Rocker Cover Gaskets
All of the above have made no differance to MPG.
Idles at 500 RPM which makes the clock lights flicker
Still goes like stink although acceration is not as smooth (feels like a rotary engine)
When i got it at 85 K was doing about 27 MPG but as i carry a bit of kit in the back i was happy for that to drop a bit (Now at 87 K)
Sometimes power steering is really heavy or if i rev hard after starting will be really light
Sounds asmatic from under the top hat, had that off cant see any potential air leaks
Water temp stays at around 90
Goes through all the gears okay
Cruise works
Instant MPG goes up to 9999 etc on deceleration
Missus getting the hump with it and me, cant blame her
ANY IDEAS, PLEASE!!!!
PS My Granny Cossie does 26 MPG with a faulty overdrive!!
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First thing to check - is it getting up to temperature?
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Might be worth checking the vac pipe that goes from the plenum to the brake servo. Check it's not rubbing against the aircon pipe by the scuttle just after the 90 degree bend from the plenum.
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Both of the above are worth checking; what fuel do you use?
You don't mention them, but given the other work you've done I am assuming you've done the oil, oil filter and air filter too?
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I have found valve timing being out to have an effect on economy too. Check the cambelt setup if unsure..
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Also - look beyond the engine... brakes binding?
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your getting 27mpg and its fully loaded?
What kind of driving? led right foot? Not going to get much more than that on average.
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your getting 27mpg and its fully loaded?
What kind of driving? led right foot? Not going to get much more than that on average.
I went to Ramsgate from Cardiff and back the other week, average speed 70, with a few bursts over that - I got 31mpg, calculated by re-filling. Fully loaded with tools, trolley jacks, exhaust system, etc..
But I agree - 27 is what I'd usually expect.
The OP needs to give more info on the type of driving - I only get 17mpg in the city ::)
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27mpg on a fully loaded estate is something I wouldn't mind having. As for the consumption in the post title - you can also try the air mass sensor. That may be the reason for low revs and not so smooth acceleration. Just changed mine a couple days ago, and all that has gone away. As for consumption this sensor plays a major role.
Beware of cheap e-bay stuff, will be much better to get a second hand original.
Cheers :)
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From my miggy these are the critical factors that effect fuel
consumption :
* exhaust leak
* old lambda sensors
* Coolant temperature sensor
* MAF (contradictory a new Maf will burn more fuel)
human factor
* a heavy right foot ;D
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Thank you one and all for your replies.
I do a lot of samll journeys but even then i was averaging 22 -23 MPG. We went up to the Lake Distraict a while ago and could only get an average of 19 on the motorway at 70 - 75 on cruise.
Going to give all the above a try, and to put my right foot on a little bit of a diet! ;D
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Also as well as checking the brakes for binding, check tyres and pressures all round and check for wear to see if geometry is out.
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Do you have the EML light come on at point of your driving? My fuel consumption is out as well but I know what the problem is, it's due to my right bank lambda sensor is shot so that is going to be changed at the weekend. As said before get the timing checked out with the correct tools not a timing light. This will need to be done with the timing set thats with the cambelt kit.
Paul :y