Power issue + odometer unstable on 1990 BMW E30

[hans2412]

Hey mates,

Been experiencing issues with my car lately where feels like it's losing torque, especially when starting off. The first gear lowers down the odometer to an extent that the car stalls unless I give more push on the accelerator that I usually do (2000 rpms v/s 1300-1500 usually).

Besides today, after a 20minutes ride from work as I parked the odometer has been behaving weirdly. The car was idly parked with engine on and hand brake applied. The odometer would continue to react though I was not sing any pedal, and the needle would just go up and down, sometimes, lower to 300rpms, close to shut down engine, but it did not. Caught it on video but actually unable to upload it here.

Did anyone of you around had this issue? What are the possible causes? How can I fix it? For info, i'm driving a 1990 E30 318i with M40B18i engine Sedan and it's my everyday car.

Thanks beforehand for your advices, guys!
Hans

[msservices]

I think you are referring to the tach, and it sounds like you may have a vacuum leak or an issue with idle control. I would also check fuel pressure.

[hotdish]

It could be something else, but a clogged fuel filter is my first thought. Replace that if you don't know how many miles are on it, cheaper than a fuel pump.

[msservices]

Does the car have any maintenance history at all? Spark plugs, etc?

[hans2412]

oh just noticed I mentioned odometer.. yeah it's the tacho behaving weirdly..

well i'll have it checked for vacuum leak and the idle valve.. however any help about how I can check for the fuel pressure?

- - - Updated - - -

well I changed the fuel pump some 2.5 years ago... right, I should get that filter checked as well.. thanks for the advice, Hotdish!

- - - Updated - - -

hey again, msservices!

Well, no maintenance history.. I bought the car three years ago.. and since I had this issue, last week, I replaced one defect spark plug wiring and just changed the 4 spark plugs to some BOSCH Platinum ones.. The car is having a good performance overall, but i'm still having that issue for starting off and when I decrease speed on second gear, where I still find it lacking power..