316 1986 hunting very badly. can anyone help??!!
Moderator: martauto
hi,
my 1986 316 is hunting. i took it into the garage assuming that all that was needed was the carb cleaned and it to be re-plumbed as there were rubber hoses hanging off it.
the mechanic said the base gasket was leaking air into the carb and making the mixture weak which makes sense. he replaced it.
now the car idles worse and cuts out. it was so bad i couldnt drive it away. can anyone shed some light on this please??!!
my 1986 316 is hunting. i took it into the garage assuming that all that was needed was the carb cleaned and it to be re-plumbed as there were rubber hoses hanging off it.
the mechanic said the base gasket was leaking air into the carb and making the mixture weak which makes sense. he replaced it.
now the car idles worse and cuts out. it was so bad i couldnt drive it away. can anyone shed some light on this please??!!
id look at te idle control valve..clean it up with carb cleaner
inspect all the vacuum hoses.mainly the main air intake one..if thats split..they cause all sorts
while ur there check the air intake rubber hose where it meets the throttle body ..underneath to the right slightly will be a small hose coming off it..into another hose...i had this problem and it turned out to be that..check the airflow meter is still plugged in.options are endless mate..its a sod of a job to sort out but when u fix it u will prob find its something stupid..good luck
inspect all the vacuum hoses.mainly the main air intake one..if thats split..they cause all sorts
while ur there check the air intake rubber hose where it meets the throttle body ..underneath to the right slightly will be a small hose coming off it..into another hose...i had this problem and it turned out to be that..check the airflow meter is still plugged in.options are endless mate..its a sod of a job to sort out but when u fix it u will prob find its something stupid..good luck
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Banjo1981
- E30 Zone Regular

- Posts: 823
- Joined: Thu Nov 27, 2008 11:00 pm
- Location: Birminghamy goodness.
It's a carb'd engine so I'm not sure it'll have an ICV...
Has the mixture been reset? If it's been leaking air for a while it may be that the mixtures all messed up. Failing that I would replace all of the vacuum hoses as they may have perished.
Has the mixture been reset? If it's been leaking air for a while it may be that the mixtures all messed up. Failing that I would replace all of the vacuum hoses as they may have perished.
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
A 316 is a carb. 1.8 (M10).
No idle control valve on these - the idle is controlled by a small actuator mounted on the carb. If it's not running right, either there's still another air leak, a jet in the carb is blocked, or adjustments were made to the carb when the previous fault existed to try to correct the running that now need to be reversed.
Trouble is, there aren't many of us around these days that know how to tune carbs!
No idle control valve on these - the idle is controlled by a small actuator mounted on the carb. If it's not running right, either there's still another air leak, a jet in the carb is blocked, or adjustments were made to the carb when the previous fault existed to try to correct the running that now need to be reversed.
Trouble is, there aren't many of us around these days that know how to tune carbs!
86 316 would be a carb engined M10. If I remenber correctly earlier ones were Solex carb and the later were Pierberg 2BE carb which is ecu controlled. I don't think you can adjust anything on the ecu controlled carb. The insulator between the manifold and carb does become porous over time so it would cause idle problems.
Your best bet is to get a carb gasket kit from dealers and clean the carb out which may help. Also check numerous small hoses on the carb to see if any are leaking. Similarly check the plugs/sockets on the carb to see they all make good electrical contact.
As most people do not understand the complex ecu controlled carb they ditch it and replace it with a Webber convertion kit which gets rid of the ecu.
All the above will not apply if it is already been converted with Webber in your case.
Your best bet is to get a carb gasket kit from dealers and clean the carb out which may help. Also check numerous small hoses on the carb to see if any are leaking. Similarly check the plugs/sockets on the carb to see they all make good electrical contact.
As most people do not understand the complex ecu controlled carb they ditch it and replace it with a Webber convertion kit which gets rid of the ecu.
All the above will not apply if it is already been converted with Webber in your case.
first join the club every one i know who had a 316 had this fault all the above i have tried i even got a manual on the carb and kit as well i got it going ok but not 100% perfect the main problem is as others have said no one really knows how to fix or understand how the carb works i even went to bmw to buy a new carb they had one but at £1100 it was a bit extreme you could get a ok 318i or do a engine swap cheaper if you want i can send all the info i have on this carb to you
yes please that would be helpful.
all the plumbing has been replaced and the base gasket on the carb which was leaking air. the previous owner has replaced the sensors but had obviously been trying to fix the problem and had bodged most of it with springs and other strange items. once this had all been put back to the way it should be and the carb cleaned it was running like a bag of nails.
all the plumbing has been replaced and the base gasket on the carb which was leaking air. the previous owner has replaced the sensors but had obviously been trying to fix the problem and had bodged most of it with springs and other strange items. once this had all been put back to the way it should be and the carb cleaned it was running like a bag of nails.
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Like I said above, either the carb adjustments are way out, or there's a blockage in it.
It's been a very long time since I set up Webbers!
It's been a very long time since I set up Webbers!
Sounds like you need to turn the idle mixture screw in a quarter turn, dont ask me where it is though cos every carb looks different...... ok not sure if this is the carb you got but found some usefull info for you.
http://www.bmwtechinfo.com/repair/main/421en/index.htm
http://www.bmwtechinfo.com/repair/main/421en/index.htm
G/90 316i M40 tickety tic!
ST185 GT4
Archless! Tech 1 project
E46 330d Sport
ST185 GT4
Archless! Tech 1 project
E46 330d Sport
This Haynes manual showes some info aswell which might be helpfull.
http://www.e30.eu/tech/E30ManualHaynescomplete.pdf
http://www.e30.eu/tech/E30ManualHaynescomplete.pdf
G/90 316i M40 tickety tic!
ST185 GT4
Archless! Tech 1 project
E46 330d Sport
ST185 GT4
Archless! Tech 1 project
E46 330d Sport

