Z3 3.0 won’t idle

Peter1450

Zorg Legend
Supporter
Joined
Apr 1, 2018
Points
84
Location
Bristol
Model of Z
Z3 3.0
As above , cars been sat since September after the drive shaft broke , battery was charged to keep it good to go.
Started yesterday and now it won’t idle without throttle. No fault codes , data says the coils are all good so any idea what I’m looking for?
Only thing that’s changed since it being parked is slight water ingress in the cabin so could it be something on the floor/ electrical?
Seems odd there are no codes and a little late but she now has a waterproof cover!
Changed the battery for the one on the Z4 and exactly the same so at least that’s eliminated.
Advice appreciated cheers
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
Check the idle control valve, it may be gummed up and stuck, they are prone to doing this. Spray carb cleaner into it and wash it out.
Probably best to take it out to clean it, once clean if you shake it it should rattle as the internals move about.
 

mwpe

Zorg Guru (V)
Supporter
Joined
Dec 8, 2011
Points
178
Location
Camberley
Model of Z
3.0
Could be an inlet camshaft sensor, you need to put a code reader on it.
 

Peter1450

Zorg Legend
Supporter
Joined
Apr 1, 2018
Points
84
Location
Bristol
Model of Z
Z3 3.0
Thanks Colb will give it a clean, smells too petrolie if there is such a word!
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
If it's smelling rich do check all the rubber intake and vacuum pipes for holes and splits unmetered air getting in will affect fuel trims making it run rich.
 

Peter1450

Zorg Legend
Supporter
Joined
Apr 1, 2018
Points
84
Location
Bristol
Model of Z
Z3 3.0
I’ll check the hoses when I pull out the idle valve although the main rubber from the maf down is genuine new so should be ok?
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
Smoke test will find any you can't see visually, some are hard to find without smoke. There is an O ring in the dipstick tube that can get missed and failed cam cover gaskets will let air in as well as oil out.
 

Peter1450

Zorg Legend
Supporter
Joined
Apr 1, 2018
Points
84
Location
Bristol
Model of Z
Z3 3.0
Unfortunately I don’t have a smoker but I recently replaced the cam cover rubbers and the oil filter housing o- ring .
 

Peter1450

Zorg Legend
Supporter
Joined
Apr 1, 2018
Points
84
Location
Bristol
Model of Z
Z3 3.0
Had a spare hour this morning so did as you advised Colb and took the idle control valve out , it was exactly as you said, gummed up and stuck, a good soak in brake cleaner and she’s running well once again . Onto the drive shafts! Thanks again for your advice it’s very much appreciated
 

Peter1450

Zorg Legend
Supporter
Joined
Apr 1, 2018
Points
84
Location
Bristol
Model of Z
Z3 3.0
Just a quick update for anyone interested, new second hand drive shaft installed this afternoon and the wife’s 3.0 lives to fight another decade!
Hats off to the guys in the states who sent these over for me, arrived within 10 days , packed superbly as nothing available from BMW anywhere no matter what the dealers websites state.
 
Top