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2002 320ci
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10 Posts
Discussion Starter · #1 ·
I’m writing here because I’ve a problem whit my e46 320ci m54 (170hp).
the minimum has something wrong but I don’t know what.
When I press the clutch, while I’m braking, the minimum, when I stop the car, go down, under 500 rpm (I think 450 rpm), the car vibrates and after it comes up around 600 rpm (i think 600 rpm, I’m referring to te correct minimum value of my car, I don’t know what is it ).
somethimes, when I’m in intense traffic and I press the clutch, after accelerate and again press the clutch (this for three or four time) the minimum go down and the car turns off .
other times, in the same condition, the minimum goes down (around 250 rpm) and after it goes to 1000 rpm (withouth pressing the accelerator).

if in press the accelerator three or four times consecutive for a bit the minimum goes Down as I described .

I cleaned the minimum valve whit throttle body cleaner and after whit wd40.
I fixed vanos problem whit the beisan systems kit.
What is the problem for you ?
INPA doesn’t report errors…
Thanks !
 

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Premium Member
2000 E46 323i, 3.0L, 2.8L and 2.0L Z3's
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2,345 Posts
Hi

By minimum, I understand that you are talking about the ile value. The idle should be 700 rpm with a hot engine.

I suspect that you have a vacuum leak. The best way to find a vacuum leak is to smoke test the engine. Read: How to Smoke Test

You can do a quick test with INPA to check for a vacuum leak.
  • With a hot engine at idle, check the 4 fuel trims, additive and mutiplicative in INPA terms. If any are >10% then you likely have a vacuum leak.
  • Rev the engine to 3,000 rpm for 30 seconds and watch the additive values. If they reduce significantly, might even go negative, then it is confirmed that you have a vacuum leak.
 

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Registered
2002 320ci
Joined
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10 Posts
Discussion Starter · #3 ·
Hi

By minimum, I understand that you are talking about the ile value. The idle should be 700 rpm with a hot engine.

I suspect that you have a vacuum leak. The best way to find a vacuum leak is to smoke test the engine. Read: How to Smoke Test

You can do a quick test with INPA to check for a vacuum leak.
  • With a hot engine at idle, check the 4 fuel trims, additive and mutiplicative in INPA terms. If any are >10% then you likely have a vacuum leak.
  • Rev the engine to 3,000 rpm for 30 seconds and watch the additive values. If they reduce significantly, might even go negative, then it is confirmed that you have a vacuum leak.
Yes, I’m talking about the idle value
Ok, during the week I will try those tests whit INPA.
Do you exclude that the problem is created by the minimum valve ?
 

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Registered
2002 320ci
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10 Posts
Discussion Starter · #5 ·
@NZ00Z3
The additive values are: additive 1 0.02; additive 2 0.04.
The multiplicative are: multiplicative 1 -4.94; multiplicative 2 -5.15.
The additive values didn’t change when I rev the engine to 3000rpm.
im confused ! Have you ideas ?? Thanks
 

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Premium Member
2000 E46 323i, 3.0L, 2.8L and 2.0L Z3's
Joined
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2,345 Posts
The multiplicative values are saying your engine is running rich at hot idle. It's difficult to get the E46 engine to run rich like that. It's usually a failing sensor.

To help sort out which one is the problem, I need some detailed information. The best way to get that is to get the cheap smart phone app OBD Fusion and an OBD2 dongle/adapter. Set OBD Fusion up as per the pdf in the OBD fusion threat and run the 3 standard logs. Also run a Rev-Rise log so we can check the MAF.

A couple of questions:
  • What year is your 320Ci?
  • How much ethanol do you have in your petrol? None, E5, E10?
Rev Rise
This test is for checking your Mass Air Flow Meter (MAF). Hot engine and Cat’s, stationary car. The test is best done just after a drive. Slowly raise the Rev's of the engine up from idle to 3,000 rpm. I mean slowly. It should take you 3-4 minutes to do this test. It takes some skill to do this test due to the lightly loaded engine. A little throttle change results in a large rev change. Don’t run up and down the rev range getting used to the control. If you stuff up the first part of the test getting used to controlling the small rev changes, then redo the test.
 

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2002 320ci
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10 Posts
Discussion Starter · #7 ·
@NZ00Z3 OK. I didn’t do the test in the correct way.
i rev the engine from idle to 3000.
tomorrow I’ll try another time to do the test ( I hope correctly).

whit INPA or other program using the K+DCAN cable is impossible to know what is the problem ?

my car was made in September 2001.
The petrol is E5.
 

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Registered
2002 320ci
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10 Posts
Discussion Starter · #8 ·
@NZ00Z3 i also noted that the instability of the idle is accentuated when outside is much hot or cold.
When the temperature outside is around 15/20C, the idle is perfect and hasn’t any tipe of problems..
 
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