car holding back!! wtf? Problem found

Post Thu Mar 31, 2011 5:35 pm

I've changed....
Plugs
Coils
Oil
Oil filter
Fuel filter
Blue temp sensor
Lambda sensor
Maf (but not had code deleted mind)

Sometimes the car flies! But other times I can definatly feel her holding back. Live data showed that my old maf was buggered and I've since changed it but the only thing I haven't done is had the code wiped.
When I unplugged the old maf the car run like shite, would having the fault still in the ecu cause my problem?
Other than that what do people think?? Its intermitant and now doing my f**kin head in tbh as I've spent shit loads on it now!

Thanks in advance

Post Thu Mar 31, 2011 7:15 pm

after speaking with you last night ant, what about the cam position sensor?

Post Thu Mar 31, 2011 7:20 pm

That has cropped up a few times when searched on google tbh glen.
But I'm thinking, wouldn't that come up on a diagnostic or live data??...

Post Thu Mar 31, 2011 7:24 pm

e30-dk wrote:That has cropped up a few times when searched on google tbh glen.
But I'm thinking, wouldn't that come up on a diagnostic or live data??...

as you say ant, it's intermittent

Post Thu Mar 31, 2011 7:33 pm

Yeah you have a point there tbh

That's the only thing it can be now, how much are they new mate?

Post Thu Mar 31, 2011 7:43 pm

these engine's are more dan's forte,
he'll probably be able to shed more light on the problem, and maybe the price of the sensor. bmwfans is showing them at 70 euro's

Post Thu Mar 31, 2011 8:00 pm

I can send you a spare cam sensor to try if you like, fault codes are usually lost when the problem is fixed on these, ive never found them to give accurate fault codes TBH so dont usually bother plugging the laptop in.
Fuel pressure regulators can cause problems, Dafs had to change his 3 times in a row before he found a good one from the scrapyard

Post Thu Mar 31, 2011 8:30 pm

If you wouldn't mind dan please...

How to change FPR on these?? Hope its not inlet off..?...

Thing is with the fault code thing,, when I had it plugged in first time he told me lambda sensor, I went away and changed it and when I went back 2 days later he said "yeah lambda is there, now its gone"?..

Post Thu Mar 31, 2011 9:13 pm

Defo sounds like cam sensor. I had exactly the same symptoms when I first put the M52 in the touring.

Post Thu Mar 31, 2011 9:25 pm

Its so annoying because when she's on her game she goes, and goes well! But other times I can feel its like she wants to go but cannot if that makes sense?..

How much of a job is it to change the cam sensor then guys?

Post Thu Mar 31, 2011 11:49 pm

Update on this after going for a rip in the car tonight....
Car starts fine and runs fine, drives ok if driving slow or using small amount of throttle, torquey enough to drive along but...

I went around a roundabout earlier 180 to go back the way I came and put my boot to the floor and she got to certain revs and coughed and splutered (like running out of petrol) but there was atleast a tenners worth in it ! So I changed to 3rd and she accelerated?.... She's done this a few times now, accelerates and gets to certain rpm and slutters...

For the record the fuel pump is new (2009) along with all the fuel lines and tank! I've taken the pump out today thinking it was that but no its brand new! And I changed the fuel filter last week....

Does this sound like a bad cam sensor and if so does it not have a fault code as its never shown up?

Thanks for your help, I'm very grateful

Ant

Post Thu Mar 31, 2011 11:57 pm

My crank sensor did that before I replaced it

Post Fri Apr 01, 2011 12:03 am

Thanks for your fast reply lee, its been really annoying me all night now!

How do I get to the cam sensor mate? Any quick tips or how to's for me? Want to tackle it first thing!

Would taking it out and cleaning the contact point make a difference at all?

Post Fri Apr 01, 2011 8:34 am

Is this fuel starvation? Makes me wonder if the tank has been plumbed up correctly, as you say the tank and lines have been changed

Post Fri Apr 01, 2011 9:15 am

Only thing is with that theory dan is that the car started off a 2.0 6pot and was fine, then I did an m20 2.5 conversion and again fine, not a hint of the problem....

But with this m50 its started doing it

Post Tue Apr 05, 2011 10:30 am

I've figured out the problem guys just to update....

Big vac leak!!! The big pipe that goes into the inlet manifoild under the throttle body isn't sitting in the hole properly, going to make a rubber seal for it today and buy some PTFE tape to wrap around it and jam the bastard in there tight!

Job done

Post Tue Apr 05, 2011 10:52 am

e30-dk wrote:I've figured out the problem guys just to update....

Big vac leak!!! The big pipe that goes into the inlet manifoild under the throttle body isn't sitting in the hole properly, going to make a rubber seal for it today and buy some PTFE tape to wrap around it and jam the bastard in there tight!

Job done

job jobbed

Post Tue Apr 05, 2011 10:56 am

I love it when a plan comes together

Post Tue Apr 05, 2011 11:19 am

Just a new O ring will do it, the tab breaking off is very common and will allow it to pull out, you can hold it in with a cable tie

Post Tue Apr 05, 2011 12:35 pm

they are a crap fit even when brand new