E30 M42 having 'semput' symptoms

[bimmer9]

Hi peeps,My E30 M42 has been having some breathing issues lately. Happens a lot in the morning and when I'm crawling in traffic. It gets very jerky especially when rpm around 2000 plus to 3000 plus. Its like something blocked somewhere.But when the road is clear and u step on it its fine.AFM replaced recently (secondhand), ICV cleaned, O2 sensor and Exhaust sensor replaced during my conversion just over 6 months ago.Any idea What else could be causing this? It has been like this for a while, but now its getting worse and more annoying.Plugs new, plug cable checked and is not the cause. Coil not replaced, can this be the cause?Can the exhaust centre box be causing this? It is quite old and probably needs replacing.Cheers

 

[evilnickwong]

Checked for any vacuum leaks?

 

[m.azharm5]

Last time my car jerky like that cause of ignition coil or fuel filter .Tq .

 

[fabianyee]

Try changing the coil pack... changed mine for less than RM500 few months back. Bought from Bavarian Auto...

 

[bimmer9]

Nick, any ideas on how to DIY check for vacuum leaks.

azhar, fuel filter is new. Must look into the coil pack next.

Fabs, yea im thinking it might be the coil pack. Might try to source one to check and confirm.

Anyone got extra coil pack lying around. Just to test. If thats it I'll replace it.