M52 2.0 cold idle problem

Hi everyone, trying to help out a friend here.

This is our situation :

The car is an M52 2.0 Euro E36.

The problem is as follows :

1. When the engine is cold, the idle is poor.
2. When the car is driven a short distance and stopped while the idle is poor, the engine will die. Once immediately restarted, the idle will still be poor.
3. The idle improves gradually and becomes normal as the engine heats up. The idle is normal once the temp gauge reaches the middle of the BLUE mark. So, this is not really hot at all.
4. Car performs perfectly after this point under all circumstances.
4. No error codes under any circumstances, except when we do the disconnect test.
5. Nothing conclusive during the disconnect test.
6. Ignition coils, fuel pump, fuel pump relay, spark plugs, fuel filter...these components are new. The icv was removed and cleaned. No change in the idle.
7. No wires for the ects, air tempsensor, etc, are pinched or otherwise shorted to ground etc.

We got the FI# code last week when we disconnected the ICV, and last night removed FI3 and swopped it with FI1. We cleaned FI3's connectors and contacts, and we did a rudimentary backflush cleaning on FI3 as well, before installing it onto FI connector 1. We repeated the ICV disconnect test. Once again, we got the ICV code as well as FI#3 code ! Again to reemphasise, this is with the fuel injectors swopped around.

So, now we suspect the ICV is busted in some very weird way and wish to confirm against another car that is working fine !

If anyone with an M52 engine can help, please disconnect the icv and start the car when its cold, let the idle stabilise if it will (should do so within 30 seconds) and then note the idle rpm, then stop the car and read the codes, then delete the codes, reconnect the icv, start the car, note the stable rpm level, let it warm up to optemp or maybe do this after a drive, then disconnect the icv, flip the throttle and let it stabilise if it will, then note its stabilised rpm with the icv disconnected, then stop the engine and reread the codes and note before deleting them and reconnecting the icv.

I've detailed the exact steps above to show you exactly what we are doing ourselves to eliminate any experimental bias on our end.

If we are doing something wrong, please let us know.

If the problem and solution is very obvious to you, also, please please do let us know.

Thank you.


Roberto

Vanos Seals--Besian Systems---do a search--find your problem

Originally Posted by poolman

Vanos Seals--Besian Systems---do a search--find your problem

That exact upgrade was done 7 months ago.

Didnt change anything

We have searched and have not found our problem, hence our request to get a baseline from someone else with a working car. Please help ! We are at wits end.

Did you replace the CCV vale and the 4 hoses that go with it--if you have a small clog in the system--that could give you the same results when cranking cold--also bad throttle responce until the engine warms up a little--vacuum leaks could do the same thing--small ones that is--large vac leaks would give you a code--but small ones can sneak by and not give up a code--just noodling things that could cause your problems

Originally Posted by poolman

Did you replace the CCV vale and the 4 hoses that go with it--if you have a small clog in the system--that could give you the same results when cranking cold--also bad throttle responce until the engine warms up a little--vacuum leaks could do the same thing--small ones that is--large vac leaks would give you a code--but small ones can sneak by and not give up a code--just noodling things that could cause your problems

No, but what I did was I took of the hose at the valve cover that leads from the CCV to the valve cover and plugged up both holes very tightly, that's the valve cover hole and the hose.
Then started the car, there is abosuletly no difference in idle.
It's still lumpy and acting the same way, shouldn't this mean that the CCV is working fine?
I also took of the oil cap to do another test, and ran the car on idle. The idle is very rough, and the sucktion is not huge when I put my hand on the oil hole, isn't this the way to test it?

By taking the hose off from the valve cover , the one that leads too the CCV--and plugging each side might prove that the valve cover gasket is OK--but what about the 4 hoses or the CCV--how does that prove or disprove that there isn't a vac leak in those areas or that the part my be clogged--You car has how many miles on it? Has the CCV ever been replaced--I don't know if this is the problem but with some it has in the past resoveled problems--another question to you--is your throttlebody drive by wire, or does it have a cable drive--if it has a cable drive---Have you given the TB a good cleaning? those can cause problems also if not cleaned regularly--hope that helps

Originally Posted by poolman

By taking the hose off from the valve cover , the one that leads too the CCV--and plugging each side might prove that the valve cover gasket is OK--but what about the 4 hoses or the CCV--how does that prove or disprove that there isn't a vac leak in those areas or that the part my be clogged--You car has how many miles on it? Has the CCV ever been replaced--I don't know if this is the problem but with some it has in the past resoveled problems--another question to you--is your throttlebody drive by wire, or does it have a cable drive--if it has a cable drive---Have you given the TB a good cleaning? those can cause problems also if not cleaned regularly--hope that helps

The car has 204.000 km on it. I don't know when the CCV has been replaced last time, I only had the car for about 1 year and always had this problem with it when it's cold, me and my friend think that the ICV is doing it, even though I've cleaned the ICV.
Also the throttle seems very bad, like it needs to be pushed down more to move the car, then when engine warms up a bit, I am talking about till the end of the blue mark, then the throttle becomes normal.
I can't really reach down to the other CCV hoses without removing throttle body, so I haven't done that yet.
Yes the throttle body has been cleaned as well, it's it is with wire or cable drive or what you call it.

You stated that you replaced the Vanos seals--whose seals were used and did you do the work yourself?

Originally Posted by poolman

You stated that you replaced the Vanos seals--whose seals were used and did you do the work yourself?

Yes the Vanos seals have replaced because I had a Vanos Mechanically Stuck code from my peake tool when I bought the car. So my mechanic replaced the seals with the best there is which is Beisan seals and the code is gone, the car had this problem even before Vanos seal replacement, so its very strange, could an ICV do this and make the throttle bad the first 5 min of driving?

Might be a long shot, but check that the drains below the cabin filters aren't clogged and filling with water. That can cause all sorts of weird engine problems, especially since you have tried so much already. Might be worth a shot.

Originally Posted by bkgreene39

Might be a long shot, but check that the drains below the cabin filters aren't clogged and filling with water. That can cause all sorts of weird engine problems, especially since you have tried so much already. Might be worth a shot.

Where are those drains exactly located?
The bulkhead windscreen ones have been cleaned and are fine.
Sorry I know this is an E39 forum, I have an E36, maybe there is difference in the drains