what does your m52 do when.....

Post Sat Feb 18, 2012 8:16 pm

ive still got a few teething problems with my conversion. just so i know what im aiming for what does your m52 do when you...

leave it to idle? mine has a lumpy idle that bounces between 500 and 900 rpm

boot it at low revs? do you get pushed back into your seat below 3000 - 4000 revs? not a lot happens with mine at all, until about 4000ish rpm then it goes pretty well, sometimes enough to spin the wheels in 2nd or 3rd if its wet.

i thought these engines would be pretty thumping low down...as it stands my first straight 6 has less bottom end than most of the 4 pots ive had!

Post Sat Feb 18, 2012 8:27 pm

randomspeedfreak wrote:ive still got a few teething problems with my conversion. just so i know what im aiming for what does your m52 do when you...

leave it to idle? mine has a lumpy idle that bounces between 500 and 900 rpm

boot it at low revs? do you get pushed back into your seat below 3000 - 4000 revs? not a lot happens with mine at all, until about 4000ish rpm then it goes pretty well, sometimes enough to spin the wheels in 2nd or 3rd if its wet.

i thought these engines would be pretty thumping low down...as it stands my first straight 6 has less bottom end than most of the 4 pots ive had!

what diff u got on it? and do you have the m50 manifold on it?

Post Sat Feb 18, 2012 8:35 pm

rich318i wrote:
randomspeedfreak wrote:ive still got a few teething problems with my conversion. just so i know what im aiming for what does your m52 do when you...

leave it to idle? mine has a lumpy idle that bounces between 500 and 900 rpm

boot it at low revs? do you get pushed back into your seat below 3000 - 4000 revs? not a lot happens with mine at all, until about 4000ish rpm then it goes pretty well, sometimes enough to spin the wheels in 2nd or 3rd if its wet.

i thought these engines would be pretty thumping low down...as it stands my first straight 6 has less bottom end than most of the 4 pots ive had!
what diff u got on it? and do you have the m50 manifold on it?

open 4.10 until gareth builds my slipper. yeh m50 mani is installed....i think i might need to refurb an injector...

Post Sat Feb 18, 2012 9:04 pm

diff is way too sort ive got a 3.91 and that sort as it is, and the m52's only come to life in the high revs with the m50 on them. did u buy the metal conversion kit? or the hose kit? and does it stall in traffic now and then?

Post Sun Feb 19, 2012 11:26 am

Iv just had my m52 on the road now for 2 days with similar results. I'm on an m50 manifold to. The low torque isn't great in mine. If I floor 3rd gear at about 30mph I don't get much but once I reach around 4500 I start to loose traction with the surge of power. It was worse the first day i took it out but I found an air leak in the servo pipe to manifold. Once I taped that up it ran much better. Your hunting at idle could mean that you have an air leak and poor performance.

One way I found to prove an air tight vacuum is the noise after you turn off your engine. There should not be any hissing for a few seconds until the ICV opens which gives a large short PISH noise. When I had the leak I had a slow hissing for a few seconds so when the ICV opened it didn't release any vacuum pressure and made no noise. I found the leak by placing my hand over the suspected pipes once I turned off the engine so I could hear the different noises as my hand altered the air leak hole.

Post Sun Feb 19, 2012 5:20 pm

Duf lambda's, faulty icv, knackered maf, vac leak??

My m52 is good low down, obv comes alive at over 3500!! I have the m50 mani also. With knackered lambda's she wasn't brill until wound up but I've since put 2 on (1 is broken) but even with the 1 goody she's come alive again

1 more to source lol

Post Sun Feb 19, 2012 10:21 pm

Mine idles at 600 and pull well in all gears,so do the couple of others ive driven including Cook`s.
Erractic idle is probably air leak/ICV related.
Have you had the codes read?

Post Sun Feb 19, 2012 10:31 pm

e30-dk wrote:Duf lambda's, faulty icv, knackered maf, vac leak??

My m52 is good low down, obv comes alive at over 3500!! I have the m50 mani also. With knackered lambda's she wasn't brill until wound up but I've since put 2 on (1 is broken) but even with the 1 goody she's come alive again

1 more to source lol

You know they are like £45 each new, and technically a service item.

Post Mon Feb 20, 2012 11:45 am

How much?? No I didn't mate, I was under the impression they were 190 quid each in bmw and 65 in gsf. Also told that oem items are the ones to have....

Where are they at this great price mate?

Post Mon Feb 20, 2012 12:21 pm

yeah i guess it could be lambdas...i think having the faults read is the next step.

ive been over trying to find air leaks with the carb cleaner for bloody ages now ive been through a whole can!

as far as the throttle body is concerned how shut do you have yours? i mean when the cable is slack and the butterfly is on the stopper is everyones fully closed or have you adjusted a little gap?

thinking this could be not helping with my slightly bouncy idle also - as everything is down to the icv alone?

oh and cheers for the input so far boys

Post Mon Feb 20, 2012 12:37 pm

Check the valve is actually shut inside the thottle, dont over adjust it if it isnt fully shut though as it will wear out the edges, this can cause high/erratic idle

Post Mon Feb 20, 2012 1:30 pm

Mine ran like shite once I'd completed the conversion. Checked all sorts, vacuum pipes, ICV etc. The problem was a faulty MAF - you don't need to swap it to find out - simply unplug it (apparently it defaults to a generic/standard map) and see what happens. Mine ran great with it unplugged, so I changed it for a replacement and it now runs really well.