M40B18 drinking fuel???

[BONNARSKI]

1990 318i Touring that is very bad on fuel, for £20 i got 78 miles till the light came on.

I have a E30 325i and a Evo 2 thats easier to run that this thing.

Back to my question, as i said the car is hard to run but going by the spark plugs it's running lean as they are chalky sandy colour.
There are no fuel leaks from the fuel lines or tank so what can it be?

I've been told it may be the FPR thats jammed open or the blue temperature sensor but i tested it and seems to be working.

I don't see how it can be hard to run but running lean or how a 1.8 can be this thirsty.

Another thing is i have a notion it may be mapped and had a few mods in it's past as it has a big 8mm metal bracket welded in behind the drivers headlight like for the AFM would be on a turbo conversion. Also it's a good going car, pulls real well until it hit's 4000rpm then it takes off, like a v-tec sensation. There is an actual noticable jump in performance.

Another thing is when either hot or cold the idle never changes, when cold it's the same as when warm.

Any ideas people?

[bmwowner]

I used to get about 24 mpg from my m40 1.8,
That was normal driving around town with the odd blip every now and then.

[Rancid]

I used to get high 20s to low 30s mpg with daily bit of motorway driving to work and some mixed in pleasure drives, so that definitely seems excessive.

[Alex]

i get 30mpg from my 318i auto and i dont fanny about

its a fsh 1 owner, low miles engine however

When was it last serviced ?

[soul4t]

Did you check the Blue temp sensor reading at the ECU?

Re Idle: It would be a good idea to check the TPS using a multimeter, they can get oily inside and stop working. Should register Closed, open and Wide open throttle.

But if it's drinking too much petrol definitely Blue temp sensor is prime suspect as you probably know!

[Billwill]

Sounds like it may have been mapped before and now needs to get the ECU back to standard.
The compression, injectors and cam may have been tampered with as well if it did have a Turbo on at some stage.

[TPS]

Blimey, stick £20 in my IS, & I got 157 miles from it!

[markus_74]

mine has v-tech sensation at 2000 rpm and when I changed afm it fixed, I feel every afm has a v-tech sensation at different rpm rate.