M50 sluggish till 4000rpm

Post Wed Feb 22, 2012 10:39 am

Hi just a quick question my m50 has started to be a bit flat an sluggish below 4000rpm then it tends to clear an go fine! Any ideas? I've had a new air mass meter an vanos seals done!

Post Wed Feb 22, 2012 10:48 am

i still have the same problem as discussed here -

http://www.e30zone.net/modules.php?name ... c&t=212184

i think it could be another air leak but im sure ive found them all

Post Wed Feb 22, 2012 10:58 am

Yea I've checked mine for leaks an sprayed brake cleaner around there an it is fine no leaks

Post Thu Feb 23, 2012 1:01 am

B15NAC wrote:Yea I've checked mine for leaks an sprayed brake cleaner around there an it is fine no leaks

we are in the same boat then.

what is your idle like?

Post Thu Feb 23, 2012 8:10 am

My idle is spot on just this flatness before 4000 not sure if its how they drive or i got a sensor going down or what!! im guessing the vanos is working by the way it kicks in with lots of power at 4!

Post Thu Feb 23, 2012 8:35 am

I felt that my m50 was a little flat down low. Had to be poked with a stick and them came alive above 4.!

I think its just the nature of them to be honest,, I put my m50 in after my m20b25, the power of the m50 up top was obv better but I think the down low torque of the single cam m20 was much more instant... I'm sure this isn't just me to

Post Thu Feb 23, 2012 11:51 am

if i wanted vtech i would have bought a jap turd! ha

ill watch some youtube videos see how everyone else is going then upload a video myself see if its not normal

Post Thu Feb 23, 2012 5:36 pm

Its pretty normal, they do feel a bit lame below 4K its only above that you feel the proper pull.

Post Thu Feb 23, 2012 5:55 pm

My m50 lasted 5000 miles because of this very reason! I felt for the money I put in it just didn't do it for me..... Putting the m52 in was the best move I made

As I said, I compared it to the m20 2.5 I took out and the low down torque difference was........ Dissapointing

Post Thu Feb 23, 2012 5:59 pm

Yea throughout the rev range you can feel the power come an go its probably just me being fussy

Post Thu Feb 23, 2012 10:04 pm

M50 non-vanos need to be peddled hard to deliver the goods

Post Thu Feb 23, 2012 10:26 pm

Well had it on the laptop tonight an there's no faults so had the evaluations wiped then had a blast an it seems good now! Thanks to monkey

Post Fri Feb 24, 2012 9:30 pm

i think ive found my leak - crack in my inlet mani seems to be the problem. ive stuck it up and so far seems fine! waiting for the next issue though....our thrown together mi16 205 was less hassle than this conversion!

Post Fri Feb 24, 2012 9:46 pm

Cracked inlet! Heard of it but never seen it, plastic weld will sort it

Post Tue Feb 28, 2012 6:39 pm

DanThe wrote:Cracked inlet! Heard of it but never seen it, plastic weld will sort it

i took a photo on my phone ill try and get it up. it looks like the manifolds previous owner has attacked the surface a bit?! what a bandit!

anyway it idles better now and has a more consistant power band. still with a step though.

to the op: maybe its still an air leak with yours? inlet mani off and have an inspect? mine wasnt found with brake/carb cleaner i just happened to see it!