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Discussion Starter #1
Please bear with me I'm new to working on bmw's.
Brief run down I purchased this car a couple weeks ago 328ci. It had the typical vacuum leak symptoms and was a good price so I thought how hard can it be.
Car ran rough when cold and would hesitate and run like crap and go into a limp if I gave it heavy throttle. It would clear and run fine once I had turned ignition off and on.
Put on a complete new ccv setup aswell as a m54 manifold.
Got it back together and running now it's even worse. Car will cough and die if I run it with afm plugged in but as soon as I unplug it runs better then ever.
Only code I'm getting is afm P010 (because afm unplugged) but short trims are 27.34% on both banks which would indicate a vacuum leak if I'm correct?. I can not get reading with it plugged in as it won't run.
Under load with afm unplugged I was seeing - 10 short fuel trims.
I have smoke tested it and cannot seem to locate any leaks. I've even now deleted ccv and gone with a pcv setup.
Tried a known good afm with no luck either.
 

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I’m surprised that you aren’t seeing P0171/0174 codes. The are classic codes for vacuum leaks. You need to smoke test the intake manifold to find all of the vacuum leaks. Do not use carb cleaner or other flammable aerosols to find leaks. Search this forum for ways to make a smoke machine.

Welcome to the addiction.
 

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2003 330cic, 2003 325iT
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I presume afm is MAF?

If it is unplugged the trims aren't that useful because the ECU is not getting all the inputs it needs. I suspect that something wasn't reconnected or plugged. Check all the plugs on the back of the manifold and the SAP vacuum line (if you have one). Also check the idle control valve (it should rattle freely when shaken).

The standard sequence for these trim issues:
1. Check fuel pressure (50psi) to diagnose weak pump or bad fuel pressure regulator
2. Smoke test for air leaks - appears you have done this
3. Sensors (O2 and MAF) - Are you sure the O2 sensors are not swapped. This can lead to substantial misfiring

How many miles on it?
 

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Discussion Starter #4 (Edited)
If it is unplugged the trims aren't that useful because the ECU is not getting all the inputs it needs. I suspect that something wasn't reconnected or plugged. Check all the plugs on the back of the manifold and the SAP vacuum line (if you have one). Also check the idle control valve (it should rattle freely when shaken).

The standard sequence for these trim issues:
1. Check fuel pressure (50psi) to diagnose weak pump or bad fuel pressure regulator
2. Smoke test for air leaks - appears you have done this
3. Sensors (O2 and MAF) - Are you sure the O2 sensors are not swapped. This can lead to substantial misfiring

Afm is Maf yes, in these parts of the world the more common name we use is afm (air flow meter)
I thought that would be the case as the sft are just so high due to the afm being in unplugged.
Everything is connected and double checked the only two possible places for a vacuum leak is the two hoses right at the bottom of intake manifold. Will remove manifold in the next couple days if I cannot fix this problem and redo it all.
Icv moves freely, I have even put my spare one in to be sure and same thing.
Their is a potential for having the o2 sensors the wrong way i haven't touched them myself since owning the vehicle but previous owner could have mixed them up I will double check after work today.
Fuel pressure is my next go to and I will try organise something so I can check that lster today also.
Vcg looks as though it has been replaced recently. I cannot see any oil around the side of the head or down the spark plug tube.
The car has 270kms


How many miles on it?[/QUOTE]
 
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