problem with starting the car

UK forum for general and technical discussion about the Z3 roadster
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zz3po
Joined: Sun 30 Aug, 2015 09:31
Posts: 75

  Z3 roadster 1.8

problem with starting the car

Post by zz3po »

Hey everyone.
Since i bought my 1.8 zed (m43 engine) i had some problems with starting the car when the engine is cold. I replaced the mass air flow sensor, it became better, but now it becabe really cold here and because of that, it is really making me hard life starting the car. At least 4-5 ignitions, in every ignition the engine turn off immidietly. Another thing is, when i finally make the car stay turned on, and start driving it, it has no power at all and is hasitate all way long untill it is getting hotter. When its getting a bit hotter the car drives reall fine. Any ideas?
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: problem with starting the car

Post by colb »

Have you checked to see if there are any codes set by using a diagnostic code reader?

What make of MAF sensor did you fit?
I would always replace with an oem one, do not use pattern parts they are unreliable, I found that out to my cost.
Check you have no air leaks on all of the rubber pipes feeding the intake side of the engine, air leaks will lean the mixture and cause bad starting and running.
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: problem with starting the car

Post by Del »

colb wrote:Have you checked to see if there are any codes set by using a diagnostic code reader?
I agree, this is the best thing to start with.

It sounds as if your car is running too lean during the start and warm up phase. At this stage my guesses would be a hole in the rubber bellows between the MAF and throttle body or faulty MAF sensor. The fact that it corrects itself when the engine is warm suggests to me that both the coolant temperature sensor and pre-cat lambda sensor are working OK i.e. the latter is correcting the lean mixture once the coolant temperature sensor tells it that the engine has warmed up. However, all guesswork until diagnostics are done. :(
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