Fuel consumption Joke

[Dan318-is]

Ok here it goes, 30 quid in my car gets me 175 miles

iv changed the airflow metre had it adjusted and it passed emissions on MOT

Iv changed temp sender also

i have no fuel leaks as iv had this checked by two garages, my tyres r inflated properly also

I have been told above 5000 revs that black smoke appears from my exhaust???

N e ideas? or is it just me not use to paying for petrol this much?

Please help me this is well gettin on my ti*s now!

[e30-320i]

your lucky mate i filled my tank to the brim last week 40 odd quid and got about 180 miles out of that and i aint got a heavy right foot i think there must be something wrong there.

[gcorky]

30 quid ,how many gallon where you live for the price.above 5k revs oh -i would not rev that high if i was lookin for economy lol

[Dan318-is]

its about 93p a litre dude

and im driving librally at the mo to be honest always keeping my eye on that gauge lol

[fuzzy]

hi mate, i think that works out to about 22-25 miles per gallon, i would think thats about average. i would be happy with that, i can get as low as 12, but average about 18 with my engine , but i have a heavy right foot , i would get the black smoke issue looked at though,cant be helping any, whatever it is.

[Dan318-is]

fook me

in that case i need a new job

[Jon_Bmw]

but this is a 318 is right, i used to get 26mpg on average from a 325 auto!
Something is definately up, but don't no sqwat about the m42 so i can't really help. Has the car been regularly serviced? But that'll probably only gain back 2 mpg.

Jon

[Dan318-is]

that what i thought mate

i mean the AFM has been sorted its passed emissions test, the only thing i think it mite bei s soemthing to with is the black smoke ocming out my car when i drive slightly fast

im not sure mate im really not

[jmc330i]

What car is this??

My 325i would happily see 25-28mpg around town - down to 15ish when having fun and then 37-38mpg on a run.

I would of thought a 318iS would be better than the 325i, so something aint right.

The black smoke - is it a puff of smoke or constant smoking when you go over 5000rpm?
A puff a black smoke isnt much too worry about, just extra unburnt fuel when youre revving hard.

[Dan318-is]

i think its large puffs

if it was constant what would that mean?

and surely unburnt fuel cant be good?

n e ideas about the fuel consumption cos im seriously running out of ideas!

[TheDutch]

22-25mpg might be average for one of those old M20 drinkers, but most of the M42s do a good 50% more. Sounds like it must be running rich for some reason.

Did you change the right temp sensor? Has it always been like this or got worse? Do you have a chip or mods that could account for this? i.e. afterburners

Don't know what else could cause this... TPS? You put the right AFM on I take it. Fuel pressure regulator? (I'm just midnight stab guessing now). If it's alot of driving before the engine warms this may be normal, but anyway there's some food for thought.

N

[Dan318-is]

its always been pretty bad on fuel

demlotcrew gave me the sender so im pretty sure its the right one,
iv got a viper 2 chip and a BBTB but these surely would effect it that much?

AFM was for a cat car but even before i put the new AFM on it was killing petrol and not idleing properly

what due mean throttle position sensor? iv also jsut had a new BBTB so the sensor on that should be fine

[jmc330i]

Its difficult to say really - your idea of a 'large puff' will be different to mine. If you can see the smoke in your rear view mirror, somethings wrong.

Black smoke would normally mean a slight over fuelling problem, hence why you get a puff of black smoke when youre revving hard and let off to change gear. My old Cav SRi was really bad at that.

Unburnt fuel or over fuelling isnt always bad, Id rather a bit too much than have it running lean, but obviously if its running too rich then that isnt good either.
That may explain the bad fuel consumption.

Best thing to do, brim your fuel tank right up to the top of the filler neck. Drive around as you would normally for 100miles or whatever, then refill your tank to the same point of the filler neck. Then you can work out your average MPG.

I normally do this if Im going on a long run, that way I can keep an eye on how the old girl is running and notice any changes.

[TheDutch]

I recall reading that the engine has two temp sensors; one for dash display, one for the ecu. Could be mistaken, but if it's true and you changed the dash one maybe the ecu one could be faulty.

If you want to check (From one of JonB's previous posts):

Temp Sensor
Hmmm! That's the worst one to get at.
It's located just below inlet ports 2 and 3. i.e. 1/2 way back the left side of the engine under the inlet manifold and is not the easiest place to get.
To test it you measure the resistance between it's two terminals.
These figures are actually measured off a good sensor:
Cold water : 3400 ohms
Hot water (from tap) : 980 ohms
Very hot water :306 ohms

If your sensor is faulty, you will get higher readings than these.
In the example I mentioned in my previous post,(also an M40), the readings were about double.

Re. the TPS, it was just an idea considering anything that could cause the ecu to insert more fuel than it should.

I assume the emmissions test would pick up excess unburnt fuel. How is the idle? Is it an ICV style hunting, or a lumpy rough sort (or both, like mine )

Cleaning my injectors made the low down performance much better and I can now easily get the OBC over 50mpg on an absoute economy motorway run (probably a BS figure, but even if it's 10% out that's still good). I don't think it would account for your discrepancy, but maybe in part.

N

[Dan318-is]

thats kind of what i did last week, put 30 quid in an got 185 miles

then put 30 in this week an so far im on about 110 an wel c how much more i get

200 for 30 quid sounds liberall to me but scrapping 170 miles is a tad ridiculous in my eyes]

i dont no were else to look

[johnono]

not going too well with the motor at the mo?

take a cloth, damp and over the pipe.. give it some and look at the cloth.. if its coaly black, then its a fuel issue.. check sparks, filter,afm,diz cap,arm,leads

if its sticky(ish,..wont be at all "sticky") then its oil... burnt rings and thats not good. possible head off job to check . check oil level, too much and it will force into the cyls, filter change and new `lighterԚ´ oil,

but DON`T leave it fella