Black smoke when accelerating/ revving

[enuff_zed]

Hi Ive found the problem! fuel injectors leaky and they shoot fuel everywhere! 2 fuel injectors where faulty and I want to check the pump as well. I havent fixed it yet so don't know 100% if this will solve the problem but Id imagine so.

Sounds like that's your problem.
Think I'd be tempted to change all of the injectors if you can afford to.
Don't worry about the pump just yet.

Was planning on it if 2 are faulty im assuming there both quite old so I'll change all of them and keep the 4 none leaky after i check the resistance just incase.
Do you reccomend any fuel injectors?

Not had to change any myself, so no experience with the various makes, sorry.

 

[colb]

BMW TIS Injector removal Z4 2.5
https://onedrive.live.com/?cid=93F57B946B4706D5&id=93f57b946b4706d5%2125941&parId=93f57b946b4706d5%2123505&o=OneUp

 

[x-driver]

Take out O2 sensors, visual check them, find out if they are aftermarket (might not work right), at that point you can also check your cats through sensor holes with a special camera.

What is your fuel consumption?

Also try to unplug MAF sensor and try to drive and see if there is any difference. Usually it gets better if MAF is bad. With the sensor unplugged the engine will run on some precalculated values. This (bad MAF giving false values) might also not throw a code.

As others said, check for vacuum leaks as well. Although this should throw a code if there was any leak.

 

[Zowen]

What is your fuel consumption?

Im getting about 35mpg overall with mix driving styles

 

[x-driver]

Had to convert this into L/100km which I'm more familiar with and found out it's unbelievably low consumption. Are you sure about this?

 

[Argyll Andy]

Had to convert this into L/100km which I'm more familiar with and found out it's unbelievably low consumption. Are you sure about this?

Many, many people on here would be delighted with 35 mpg - I’ve not had anything close in any of my Zeds. Last group run out we had we were all averaging under 20 mpg

 

[x-driver]

I'm having cca 25 mpg and I think it's pretty good I'm used to 19-21 mpg with my e39 530iA... 35 mpg seems unreachable for 3.0i M54 engine.

 

[Zowen]

I'm having cca 25 mpg and I think it's pretty good I'm used to 19-21 mpg with my e39 530iA... 35 mpg seems unreachable for 3.0i M54 engine.

Uhm the attached photo was a 90 mile trip down the motorway driving sensibly, I reset it before the trip. ive been getting around 400 miles a tank? See I could probably always get good mileage but then whats the point in the car?

 

[x-driver]

I kept that in mind of course I was always talking about average consumption, not the best possible with careful driving.

 

[Zowen]

I kept that in mind of course I was always talking about average consumption, not the best possible with careful driving.

530i will be much heavier though got to remember z4 weighs next to nothing even ragging it everywhere I think I'd get 20mpg haha

 

[x-driver]

Indeed.
However I didn't get myself a 3.0L for not using it's power

 

[Zowen]

Indeed.
However I didn't get myself a 3.0L for not using it's power

Agreed still think the most annoying part of my Z4 is that the insurance is cheaper than my fiesta. Im recently 20 and I really expected it not to be cheap and its annoyed me that its cheaper than my fiesta by £200! Makes me want to get rid of the fiesta and find something cheaper must be something about the fez that makes it so pricey

 

[enuff_zed]

must be something about the fez that makes it so pricey

Yup!
Every second teenager gets one and crashes it, so the premiums reflect the likelihood of the insurance company having to pay out.
When my lad started to drive he wanted a 1300 Fiesta as everyone assumes below that capacity makes it cheaper to insure. He ended up finding a really nice 1400 Ghia. His mates described it as a granny's car but precisely for that reason the insurance was half what it would have been for the smaller engined one.

 

[Zowen]

must be something about the fez that makes it so pricey

Yup!
Every second teenager gets one and crashes it, so the premiums reflect the likelihood of the insurance company having to pay out.
When my lad started to drive he wanted a 1300 Fiesta as everyone assumes below that capacity makes it cheaper to insure. He ended up finding a really nice 1400 Ghia. His mates described it as a granny's car but precisely for that reason the insurance was half what it would have been for the smaller engined one.

Dam got 1.25 fiesta 800 for the year, 3.0 z4 600??? I thought it wouldve been as its the most stolen car in the UK I always consider selling it and getting a car with cheaper insurance (Leon FR been quoted 550) but at the same time ive had it 2 years and I haven't had to fix or pay anything on it outside of services and MOT so maybe the extra insurance isnt so bad woth how little repairs I pay