the m20b23

[bkelsey86]

If anyone knows anything about servicing this engine or any info such as valve adjustment info and idle control info please inform me or point me in the right direction for some info.

Thanks,
Brendan

[M-technik-3]

Pretty much the same things that apply to the M20B25 apply to the 2.3l M20 engine.

[bimmerlover]

Pretty much the same things that apply to the M20B25 apply to the 2.3l M20 engine.

As far as valve adjustment and things like that.. I have to agree.

There is a little bit of technical info on m20b23s on www.e21bmw.net.
Specifically what do you need to know about the idle control? I might be albe to help ya out.

*I'm not sure about what differences there might be between your 85 b23 and my 82.

[bkelsey86]

well right now the car "hunts" with no steady idle now on my 325e there is an idle control valve to adjust this im just nto sure how to do it on the 323. I'm also changing all the vacuum houses in case therer are leaks in those.

[M-technik-3]

Pretty much the same things that apply to the M20B25 apply to the 2.3l M20 engine.

As far as valve adjustment and things like that.. I have to agree.

There is a little bit of technical info on m20b23s on www.e21bmw.net.
Specifically what do you need to know about the idle control? I might be albe to help ya out.

*I'm not sure about what differences there might be between your 85 b23 and my 82.

the injection controller is differant that's about it. K jetronic and LE jetronic. The engines are just small displacement M20's

[Axxe]

well right now the car "hunts" with no steady idle now on my 325e there is an idle control valve to adjust this im just nto sure how to do it on the 323. I'm also changing all the vacuum houses in case therer are leaks in those.

You probably have a vacuum leak somewhere. Check intake elbow and all the connections in that area. To check if you have solved the problem fully, open the oil filler cap. This creates a huge vacuum leak. If nothing happens you still have a leak, keep looking, mine was underneath the throttle body (the TPS). A good way to check is to have a friend rev the engine, then cover the front of the AFM intake hole with you hand. This will make all the vacuum leaks more audible. Not to much, you might crack the elbow if you let it get sucked in completely.

[bkelsey86]

well after looking at vacuum diagrams I have found out that for one reason or another the Fuel pressure regulator has been removed. This may be causing the problem adn I think the noisy lifter i thought I was hearing may be the injectors being overloaded with full pressure from the fuel pump.

[BavarianBimmer]

adjusting valves :

M20b23 : Inlet : 0.25mm
Outlet : 0.25mm

M20b25: Inlet : 0.25mm
Outlet : 0.30mm


M20 2.3 i and 2.0i are the same specs
2.5i is another concept of the M20

[tuliongolo]

probably have a vacuum leak somewhere. Check intake elbow and all the connections in that area. To check if you have solved the problem fully, open the oil filler cap. This creates a huge vacuum leak. If nothing happens you still have a leak, keep looking, mine was underneath the throttle body (the TPS).

my car (323i/L-jetronic) has problem with the idle, after the motor (m20b23) is warmed up. The problem it's an unstable idle between 700 and 900 rpm aprox., and sometimes motor stall.

Well, I opened the oil cover and the idle became stabilized, when i close the coil over...the unstable idle starts again!!

[code-]

Yeah idle on our cars is a real pain to troubleshoot. Here is waht I did:

Messed with the throtle stop (closed completly, then opened a tiny bit. Made it idle well, but just a tad high)
(Mis)adjusted mixture (no help there)
Adjusted timing to lower idle :shock:
Adjusted timing again so it would drive
Gave up and was happy with a stable 900RPM idle ;)

EDIT: When I once forgot to put my oil cap back on :shock: it idle super-flawlessly and steady at 500 RPM. Didn't make much of a mess ether :)

[carazy]

Lol I had this same problem.
I just took apart and cleaned the hoses all the way from the AFM to the throttle body. That fixed the issue all up.
Our idle is controlled by vacum. There is a bypass that opens up if the vacuum drops to much on one side. You can adjust the amount this valve will open.
So it's either a sticky valve or a vacuum leak

Good luck.