M52 Still lacking Power With New AFM

[tbone455ci]

Well lads, im back again & still none the wiser. Been driving in different ways to show the symptoms from cold engine to warmed up engine.

With engine cold/warm it would rev past 6000rpm with little or no hesitation but the warmer it got the worse it got at higher revs.

If I build the revs it will rev but you can still feel it stuttering. If I floor it WOT it stops revving at 4000rpm, just Spluttering?

Swapped the O2 sensor plugs this morning and it ran worse, Spluttering from 2000rpm.

Disconnected O2 sensors & ran the same with no revs beyond 4000rpm.

Plugged them back in & the same no revs beyond 4000rpm.

Garage opposite work said it's probably AFM, got genuine AFM & fitted but still the same.

Plugged in mates scanner again and There were new codes but these were due to unplugging and swapping the O2 sensors and the AFM. When these codes were cleared they did not return. The codes were:
214 Vehicle speed sensor - wire had broken of sensor on diff
55 O2 Sensor 2 Heater Before CAT - had swapped O2 plugs and disconnected
25 O2 Sensor 1 Heater Before CAT
8 Air Mass Sensor - had unplugged AFM, still ran the same

I filmed the results for the live data from the scanner. Not too sure what the graphs mean but if anyone can make them out or point me in the right direction, that would be great!

Here are the youtube links:




BMW_E30vert on E30 zone said I could go to his place & try a genuine camshaft sensor, which is truly appreciated mate. Its just getting over to him as I have a real busy couple weeks ahead. Might be able to do Wednesday.....

I bought a europarts camshaft sensor 2 weeks ago which cleared the camshaft sensor code and cured the misfiring it had all through the revs, again this misfiring got worse when the engine warmed up, could it be related?

If it was the sensor why doesnt it show a code now & wouldn't it splutter when cold? Maybe it would be worth me getting over to BMW_E30vert but does anyone think it could be the europarts CS sensor?

All I can think of now is fuel Pressure related? But when i clamped the fuel return pipe it was pretty much the same. Im not too sure why it revs ok when engine is cold/warm & when it warms up starts holding back and spluttering. Could it be the M52 temp sender?

Im at the point where im just guessing now but dont want to spend a fortune on parts not needed.....

Im sure someone out there has had this or similar symptoms.

Thanks again for the responces I've had so far........

[E30BeemerLad]

I am inclined to go with cam sensor (more gut instinct than anything) as I had issues when I first did my M52 swap years ago. I remember thinking what's all the fuss about with these engines, no quicker than a M20.

Changed the cam sensor and the difference was staggering in terms of responsiveness, felt like it was gaining another 100bhp.

Try a genuine sensor as you have the opportunity to blag one to try. The arse dyno will tell you immediately if it's working or not. Aftermarket ones have been known to be gash.

[tbone455ci]

Cheers mate, going to try the cam sensor

[rich318i]

Get one from the main dealers 100% if that doesn't fix the problem then.........