E30 Zone

I have a 325i m20b25 and recently its been playing up. runs fine for a while then starts to splutter and wont take any throttle. i have to pull over for a bit, it idles ok then after a bit it goes back to normal and drives fine. then after a bit it goes again, so far ive changed the fuel filter as i thought it was a blockage but it still happens. any suggestions would be appreciated.

Possible crank position sensor.
How long is a while and a bit?

well it started doing this last month, it lasts for maybe a minute or 2 at the most. but yesterday it took me ages to get home. 5mins fine then 2mins no throttle then 10 mins fine and 2mins crap. i havent bothered with it today as i cant be assed breaking down again

Do you have to turn the engine off or will it recover just idling?

no it seems to idle fine but soon as you touch throttle it dies and goes back to idle when you lift off. then it just goes back to normal for a few miles till it happens again.

If you have access to a multi meter check the throttle position switch under the throttle body and the afm through its range of travel. It's been ages since I worked on a m20 I'm sure the search will show what values to look for.
It shouldn't take too long to get this sorted.

Throttle position switch at a guess but I'm not a time served E30 trouble shooter.
If you do a search you will find the test values.

If you have access to a multi meter check the throttle position switch under the throttle body and the afm through its range of travel. It's been ages since I worked on a m20 I'm sure the search will show what values to look for.
It shouldn't take too long to get this sorted.

Lol beat me to it Supafly
You may need to do the test when it plays up.

Either way they're both easy fixes. TPS needs a hole drilling in it and contact cleaner sprayed in til its clean or replace and the AFM needs the arm bending slightly to move on a clear piece of track.