E30 318i idling problem
Moderator: martauto
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Royden
- E30 Zone Newbie
- Posts: 3
- Joined: Thu Dec 05, 2013 11:00 pm
Good day guys. I have an E30 cabr with a M40 motor. I am new to the BMW world,so will try my best to descide my issue. I can't get my car to idle properly. The idling fluctuates and I have now changed the cleaned the whole throttle boddy including injectors, changed all of the air hoses, fitted a new airflow meter and idling unit (fitted to the throttle boddy), but no luck. When I rev the car hard it still sounds like it has power (so its not suffocating). Please help. Thnx
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Brianmoooore
- E30 Zone Team Member
- Posts: 49360
- Joined: Mon Jan 10, 2005 11:00 pm
Check that the throttle position switch is working and adjusted correctly, and that the closed throttle stop and AFM adjustments are still set where they were at the factory.
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Billwill
- E30 Zone Regular
- Posts: 363
- Joined: Sun Jun 26, 2011 11:00 pm
- Location: South Africa
Yes check the TPS is working properly...must "click" when throttle is relaxed and you need to check the switch is working all the way at the ECU connectors.
In case someone has moved the factory set throttle stop....lots of people do this to try adjust the idle..then move it back so that there is virtually no gap of the butterfly to the throttle body's insides....then check TPS.
When you changed the idling unit (ICV) did you make sure the arrow on it is pointing in the direction of the airflow?....very easy to put it in backwards.
You may need to spray Carburetor Cleaner around all the pipes and gaskets to check for a vacuum leak and check valve cover is not leaking....don't forget to check the hose going to the brake servo for a leak!
You can pull out the ICV....block off the hole in the intake manifold with a cork. leave it electrically connected and watch it while you rev the engine...you should see it open and close a bit in a sort of "flutter" as it tries to correct the air-bypass....if it does not move then there may be an electrical problem or the ICV needs some cleaning and lubrication.
Does it only idle bad when cold? If so then check the Blue Sensor under the intake manifold.
Do you have good spark plugs and HT leads...I find the M40 only likes NGK spark plugs!
Does the motor actually have power when you drive it and rev properly to the rev limit?
In case someone has moved the factory set throttle stop....lots of people do this to try adjust the idle..then move it back so that there is virtually no gap of the butterfly to the throttle body's insides....then check TPS.
When you changed the idling unit (ICV) did you make sure the arrow on it is pointing in the direction of the airflow?....very easy to put it in backwards.
You may need to spray Carburetor Cleaner around all the pipes and gaskets to check for a vacuum leak and check valve cover is not leaking....don't forget to check the hose going to the brake servo for a leak!
You can pull out the ICV....block off the hole in the intake manifold with a cork. leave it electrically connected and watch it while you rev the engine...you should see it open and close a bit in a sort of "flutter" as it tries to correct the air-bypass....if it does not move then there may be an electrical problem or the ICV needs some cleaning and lubrication.
Does it only idle bad when cold? If so then check the Blue Sensor under the intake manifold.
Do you have good spark plugs and HT leads...I find the M40 only likes NGK spark plugs!
Does the motor actually have power when you drive it and rev properly to the rev limit?
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Brianmoooore
- E30 Zone Team Member
- Posts: 49360
- Joined: Mon Jan 10, 2005 11:00 pm
Not only working, but adjusted properly. It must switch almost immediately the throttle leaves its stop.Billwill wrote:Yes check the TPS is working properly...must "click" when throttle is relaxed and you need to check the switch is working all the way at the ECU connectors.