how long for ecu to relearn?

[fo3]

Backstory: I went to repair any vacuum/air/intake leaks on my m50b25 about 2 weeks ago, so I had manifold gaskets, intake boot and IAC hoses etc all set for the job. But when I got in there I found the plastic iac fitting to the manifold broken, and also I broke the dipstick breather to intake boot plastic elbow trying top pull it off the old boot.
I tried the local BMW dealer for spares figuring I could get it quick but they said 3 weeks ex Germany. So I ordered from the USA instead as I normally get parts in 4 days. But UPS sent my parts on a great northern pacific tour, via Alaska, Korea, China and Singapore! Took almost 2 weeks to get a very small box with some plastic fittings and the battery was disconnected that whole time.

Question: Anyway, I finished the job today but it was running like a pig. Could barely idle at all for 5minutes and I thought I'd blown it big time. But now it drives OK I figure that was just relearning time after having the battery disconnected so long. Now it idles, but rougher than before. I'm not sure if it's still learning after only a trip around the block or I did my job wrong. Anyone know how long it takes for the ECU to sort itself out and get a smooth idle?

E: I'm worried I didn't seat the intake manifold gaskets right or I did something bad to the IAC solenoid by cleaning or whatever.

[fo3]

Took it for another test drive. bad misfiring now somehow even when it wasn't on the first test drive.
Seems electrical like I've busted a wire or coilpack somehow. E: or stuffed a cylinder?
Absolutely nothing I can do about it this time of day (5pm). Sun in my eyes, everyone on the road, going to get dark in 30min anyway. Going to get drinks on.

[AHenry014]

The car should run very well prior to "relearning". Youve missed something.

[fo3]

Everything is connected. Nothing is missing so something is definitely broken. Either the icv or something by coincidence unfortunately
I'm going through everything, spark, fuel or air leak. It's strange though the idle was the problem but eventually started working fine (took it for a run around the block up to 3000rpm and it was smooth. After parking it and going on a second drive it got worse and now seems running on 5 cylinders, misfiring, exhaust backfire and putting, no power or rev) so it seems like something more major than an intake gasket or minor air leak

All injectors seem ticking.
All vacuum lines connected (yes even the small one to the regulator I hadn't changed.)

I'm dealing with 2 maybes.
First is spark, maybe I've done something - 2 weeks ago when starting the job I unplugged the coil packs thinking they needed to come off. They didn't so I reconnected them 2 weeks ago. They are right way round as wire length only gives one option, but maybe stuffing with them killed one that was almost dead. Going to play around with them tomorrow.

Other is air leak. Could be the manifold gasket, I'll have to lift it off again tomorrow. Could be the Icv. I had it off the car and ran some alcohol through it and I'm pretty sure it only goes in one way (top hose push on, bottom hose clamp on). It's plugged in, I'm looking at the bmw service manual right now for testing. Maybe I damaged it by running alcohol through it to clean it?
Anyway, I'm leaning to this unless been told otherwise because I know when running the engine last put my ear to a hose and them was poking the hose around like a rudimentary stethoscope to listen to injectors. I could hear what seemed like a lot of airflow under the manifold. Could be normal internal manifold noise, could be a lot of air going through the icv when it shouldn't?
Also when turning off the engine a loudish "ssshhh" sound of air/vacuum equalising noise, which I don't remember happening before. But it could all be normal.
It's been so long since I've looked at the car due to postage delay and it makes it difficult when the car is still very new to me in the first place. E: Also this car doesn't have a CEL so I'm not getting help from it.

[sbeckman7]

I would say it’s not normal to hear that whooshing sound when shutting the car off, sounds like one of the items you fixed/replaces relates to the vacuum system was improperly reinstalled. Are you sure everything is just as it was before you started? Sometimes it helps to take everything apart again and reconnect it while inspecting each piece.

[fo3]

Yes, sure as I can be and nothing will come to me now all of a sudden by re-doing it. There's only about 4 vacuum lines and fittings here, everything kind of only fits in one place. My only doubts being the Idle control valve. I'll have to get it on ramps or jackstands as I can't see anything abnormal from above

[The Chauffeur]

I agree with sbeckman7 , sounds like a MAJOR vacuum leak; when I got my 525, most of the hoses were severely dry rotted (even the intake boot was cracked) and it never gave problems like the ones you're experiencing. Did you also change the fuel pressure regulator vacuum hose? that one is often overlooked, as it's almost invisible under all the manifold mess...

[fo3]

Yes I agree, a major leak but there isn't one visible!

I'm on the verge of giving up.
I started the car this morning to drive up on ramps. It started and idled OK, no loud air sound heard when shutting it off either.
I couldn't find anything wrong so I took it for a drive. It ran fine but a bit sluggish I think (don't hold me to that), but after 1/2 mile it started misfiring again.

Started with the coil packs, removed any single on of them and retesting told me nothing as idle was so rough very little change could be detected.

So I'm nowhere, being cold and running OK and warming up and misfiring could still be either (cold fuel enrichment, heat breaking down electrical...)

I ripped the manifold off and checked the O ring seals, not perfect IMO due to 4 tiny ridges in each oring stopping me pushing them in more, but all were in the right place so to speak.
And yes in my haste I snapped the idle air plastic fitting on the back off the manifold, so I'm worse off then when I started.

Might have to get it towed, odds are a bmw mech is going to charge like a wounded bull to even look at it here in australia
The IACV can only go in one way right? The top is the barbed outlet side of it that goes to the back of the manifold and the plastic breaky connector, and the bottom is the single ringed outlet side of it that needs a hose clamp and has the long hose that goes to the intake boot?

E: Have to add that something major is wrong just by when I tried to start it the first time. It was hard to get it going and was constantly stalling for a minute. Like something seriously wrong. But now the problem is coming and going and it's not like vacuum lines are rerouting themselves or plugging themselves back in constantly.

[fo3]

Well I tested the IACV. terminals 1-3 is 45ohm. When powered up it opens halfway.

I'm going to refit the old intake o rings just in case the news ones don't seat properly. Check the manifold for cracks I may have caused.
But I need a break from this particular disaster in my life.

[Mykk]

I too agree, something was missed. The ECU isn't intelligent enough for an extensive relearn procedure beyond making fuel trim adjustments at first warm up cycle as it goes into closed loop.

[heifetz17]

This may sound stupid but I've had the icv hose not snap in all the way to the intake manifold and popped out upon installing the manifold. Could this possibly have happened to you? Or possibly a torn o-ring on that same fitting?

[4dri4n]

Backstory: I went to repair any vacuum/air/intake leaks on my m50b25 about 2 weeks ago, so I had manifold gaskets, intake boot and IAC hoses etc all set for the job. But when I got in there I found the plastic iac fitting to the manifold broken, and also I broke the dipstick breather to intake boot plastic elbow trying top pull it off the old boot.
I tried the local BMW dealer for spares figuring I could get it quick but they said 3 weeks ex Germany. So I ordered from the USA instead as I normally get parts in 4 days. But UPS sent my parts on a great northern pacific tour, via Alaska, Korea, China and Singapore! Took almost 2 weeks to get a very small box with some plastic fittings and the battery was disconnected that whole time.

Question: Anyway, I finished the job today but it was running like a pig. Could barely idle at all for 5minutes and I thought I'd blown it big time. But now it drives OK I figure that was just relearning time after having the battery disconnected so long. Now it idles, but rougher than before. I'm not sure if it's still learning after only a trip around the block or I did my job wrong. Anyone know how long it takes for the ECU to sort itself out and get a smooth idle?

E: I'm worried I didn't seat the intake manifold gaskets right or I did something bad to the IAC solenoid by cleaning or whatever.

If the car shaked like weird when you first fired up the engine back again then you can be sure it has reset to stock values. It will take like 3 to 400 kms to run normal again.

I had 2 o 3 times the car disconnected from the battery and experienced the same thing. However, when I wanted to restore back to default values, without having the car sitting one week on lrder to erase all parameters from the DME... it was impossible. None of the things suggested anywhere worked...
Like for instance, disconnect battery, join both possitive and negative and turn key in switch position 2. It didnt work. Removed DME and left disconnected for the whole night didnt work neither

[4dri4n]

Everything is connected. Nothing is missing so something is definitely broken. Either the icv or something by coincidence unfortunately
I'm going through everything, spark, fuel or air leak. It's strange though the idle was the problem but eventually started working fine (took it for a run around the block up to 3000rpm and it was smooth. After parking it and going on a second drive it got worse and now seems running on 5 cylinders, misfiring, exhaust backfire and putting, no power or rev) so it seems like something more major than an intake gasket or minor air leak

All injectors seem ticking.
All vacuum lines connected (yes even the small one to the regulator I hadn't changed.)

I'm dealing with 2 maybes.
First is spark, maybe I've done something - 2 weeks ago when starting the job I unplugged the coil packs thinking they needed to come off. They didn't so I reconnected them 2 weeks ago. They are right way round as wire length only gives one option, but maybe stuffing with them killed one that was almost dead. Going to play around with them tomorrow.

Other is air leak. Could be the manifold gasket, I'll have to lift it off again tomorrow. Could be the Icv. I had it off the car and ran some alcohol through it and I'm pretty sure it only goes in one way (top hose push on, bottom hose clamp on). It's plugged in, I'm looking at the bmw service manual right now for testing. Maybe I damaged it by running alcohol through it to clean it?
Anyway, I'm leaning to this unless been told otherwise because I know when running the engine last put my ear to a hose and them was poking the hose around like a rudimentary stethoscope to listen to injectors. I could hear what seemed like a lot of airflow under the manifold. Could be normal internal manifold noise, could be a lot of air going through the icv when it shouldn't?
Also when turning off the engine a loudish "ssshhh" sound of air/vacuum equalising noise, which I don't remember happening before. But it could all be normal.
It's been so long since I've looked at the car due to postage delay and it makes it difficult when the car is still very new to me in the first place. E: Also this car doesn't have a CEL so I'm not getting help from it.

You clearly have some vacuum air leak around. Check your power brake booster... it has a pipe that joins with it... I had an air leak there. Nothing that some silicone gasket substitute coudlnt repair n.n' yeah I know it sucks.
You should check aswell that the pipe coming from the ICV is totally fitted inside the intake manifold and properly sealed with a good O-ring.
And you should check aswell that the ICV moves loose without any resistance. Like if you shake it with your hand, the valve inside should turn totally free without resistance. If everything is in place... and it persists, then you should try and disconnect some sensors in order to find which one is failing. Start by disconnecting the MAF sensor and see if it gets better. A lot of people use compressed air to clean them and they broke them that way...

[fo3]

I rebuilt the entire thing yesterday, re-used the old manifold gaskets as I couldn't trust the new ones. I left the throttle valve off so the manifold could dry out (I degreased it and checked for cracks)
No vacuum leak guaranteed.
Today I connect up the throttle valve and hope for the best. It's even worse then yesterday!

Now, I have to point out that the manual door locks on my car do not work. I found this out on the first day I bought the car because it had a dying battery (which I knew when I bought it), when the battery got flat I couldn't unlock the car. So with battery disconnected while working on it, and the car locked up overnight (or for say 2 weeks while waiting on parts), the bonnet is down but not can not be fully closed, otherwise I'll be stuck and have to break in somehow.
And it rained a lot last night and this morning, sometimes I'm forced to work on it while it's raining...And it rained a lot during the two weeks I was waiting for parts

See where I'm going with this?

The spark plug wells were full of water. Bad spark. Problem now fixed as of 3min ago*

But of course I'm back where I started, original old manifold inlet gaskets and broken IACV to manifold connector
At least it runs now!

[KVF]

I just had a similar issue and it actually turned out to be my battery, but sounds like you got it solved... Now just change it all back.

[fo3]

Well i know I fixed something. Before the engine was dull, down on power below 3000rpm, but started to pull OK at 4000rpm (I'm talking about ever since I had the car, not just after my stuffing around 'repair'). Now the engine seems to have a lot more power, starts pulling at about 2200rpm.

I still have to do something about the idle. When removing the manifold the first time I adjusted/undid the throttle cable,(leaving the throttle body on the manifold). I noticed that the cable was broken near the end at the adjuster so right now I've got to deal with that. The idle is quite erratic now since me playing with it, so I've got to set it up the best I can to be close to how it was set/adjusted before.

I've been doing test drives around the block to see if it's still running and not going back to misfiring. On the last one I did seemed like a minor misfire but I could be paranoid, and it didn't stay misfiring like all the previous breakdowns.

Oh well, next time I order something from the US (probably when I get around to RTABs), I'll get that connector again and a throttle cable. E: and coils + plugs.

[fo3]

I've been giving it an italian tune-up and I impressed with how well it goes now. Every e34 I looked at was owned by a 'mechanic' and they all seemed down on power. On some I was especially worried about blocked cats as they were that bad. This one I bought seemed the best at the time engine wise, but I still was not impressed by it's performance when comparing it to 150-170kw domestic cars I drive - it felt like it had ~110kw. Now it feels and goes like it should, and like they must do for everyone else who likes their bmw/m50. Man, I've been missing out as I had such a boring car before.

I'm not sure if the cause of the previous low performance was leaks or whether the ecu needed a reset (the latter may have been the case if the PO ran it on regular fuel and drove everywhere slow?).
Just then I drove to the local auto parts shop and got 3mm vac hose for the fuel regulator and some m6 nuts and bolts (lost a couple for the covers). The car drove well, no misfire and again, heaps of power and go, also the idle is much better after the engine got nice and warm and I adjusted the throttle cable the best I could to raise the idle a tiny bit which I think I only needed to do because the cable is broken.

Now a storm is coming in, which is a shame as I wanted to fit shogun's door gaskets.

[KVF]

The idle on these cars are electronically controlled. Adjusting idle via the throttle cable is merely masking any idle issues by partially opening your throttle, as if you just lightly put your foot on the gas. You don't want to do that.


Sent from my iPhone using Tapatalk

[fo3]

The idle on these cars are electronically controlled. Adjusting idle via the throttle cable is merely masking any idle issues by partially opening your throttle, as if you just lightly put your foot on the gas. You don't want to do that.

Just to revisit this topic, I completely agree. I understand the significance in the names of the components I was just messing with, idle air control.
It's just that with a broken throttle cable and the fact I haven't even verified things like good spark and fuel, I just needed to get the car going because the weather has been atrocious. Seemed no point in letting it run rough while retuning itself if it may not be a good tune anyway.
Small victories and stuff like that
Getting it into relearning mode was never planned. I have not check or replaced things like plugs, coils, injectors or oxy sensor. Also I hadn't replaced the fuel reg vac hose at the time and I knew I broke a connector.
I will attend to those parts before I reset it again, probably after rear suspension repairs.

Anyway, after a few trips in the car and while it was warm I wound back the tiny tiny amount of throttle I had put into it and the idle didn't change much, if at all, so it all looks good for now. We'll see how it runs tomorrow when cold.