1500-2000 rpm runs sh1t.

[ah]

Just put a brand new dizzy cap + rotor arm on to try and sort my ongoing fault but no such luck.For those who don't know my fault,between the shown rpm it miss fires and kangaroos,after that it flies.Ive tried almost everything I can think of apart from fuel injector service,it's done 112k.Any ideas? It may still be missing after above revs but under hard acceleration and high speed it's a job to know.Also on idle I'm sure its missing.

[Yeti]

air leak around inlet

[Yeti]

check pipes split etc lol

[ah]

Thanks guys,I have had a good look for air leaks,but couldn't find anything.I would like to do one of those smoke tests to be more conclusive.

[Jona1971]

Mines the same and I've had my injectors cleaned.
Convinced its an air leak but can't find it.
I've just bought some smoke test matches...

[ah]

Mines the same and I've had my injectors cleaned.
Convinced its an air leak but can't find it.
I've just bought some smoke test matches...

Please let me know the results from the smoke test.

[JackCornick]

I'm currently having a similar issues between 2000-2500 rpm. I'm guessing at the moment it's the fuel pressure regulator. It only happens on partial throttle, full throttle its fine. I'm trying to find the how t, but Iv read on the forum if you disconnect the vacuum hose from the inlet manifold and plug it up, the the regulator will run at full fuel pressure 3bar. If running at this pressure cures the issue, then the regulator needs to be replaced. Obviously running at full pressure for a prolonged period isn't recommended. I have yet to try this, but it's next on my list a‘aaa»

[Jona1971]

let us know how you get on

[Brianmoooore]

If problems with ignition components have been eliminated, the next thing I'd check for problems at light throttle is the AFM. Easily tested with a 6 or 9 volt battery and a meter.

[Jona1971]

How do I do thatBrian?

[Jona1971]

I've isolated the brake servo to rocker cover pipe and its running much better. (Brakes need a heavy right foot though)
When the replacement pipe arrives I'll plug it all in and see what's what...

[Jona1971]

2 years of messing about and 5 quids worth of rubber pipe fixes it, result. a˜€

[Brianmoooore]

How do I do thatBrian?

Connect the battery across the pot. and measure the voltage on the wiper contact as you move the flap from closed to fully open by hand. I'm sure it's all detailed in the wiki, but it looks like it's irrelevant now.
Congratulations on finding the main problem - an air leak after all, but don't assume that the rest of your investigations have been a waste of time. Chances are that you've eliminated other small problems along the way, and now the car is operating as BMW intended. There's no reason why, after 30 years and 100k - 200k miles, that these engines can't still produce every single one of their original BHP.

[Jona1971]

That brilliant, thanks Brian.
Let's hope the OP can solve his problem too. a˜€

[Brianmoooore]

Ooops! Thought you were the OP.