Cold start issue. Jumping revs. After switching to 241E DME SW

[NiBe]

Hello,

I don't have mine video but this is basically the same:

Revs are jumping during the cold start sequence when air is pushed into exhaust by the secondary air pump. After that no problem at all.

It started after I updated my DME to 241E software. Need to note that the update was not smooth and it failed for the first time (because wrong cable) and I lost engine adaptation values thanks to that. After successful update to 241E I was getting these errors: 2739, 27C5 so I changed the MAF for secondary air pump and the errors never come back but the revs are still jumping.

What is the problem? Secondary air pump? Idle control valve? Should I downgrade back to original DME SW? Will it solve itself after the engine creates new adaptations? (it is like 5 cold starts and 150 miles since the DME update) What would you do?

27C5: http://wiki.rcollins.org/core/index....r:_27C5,_P2430
2739: http://wiki.rcollins.org/core/index....,_P2432,_P2433

Thanks!

[Lozza47]

It's a bit odd that it started after the DME update.

As the new update has different tuning information, maybe give it bit of time - run a new tank of gas and get the adaptations set up then check back in?

EDIT: could also try disconnecting the air pump and see if the idle issue is still there, can you hear it running?

[chenium]

The issue was the idle control valve. He wrote this in the comments:

It was the idle valve and it was repaired under a recall. Car is also a 2008 and is long gone and I no longer have it. Thanks though!

[NiBe]

Originally Posted by chenium

The issue was the idle control valve. He wrote this in the comments:

Yes I'm aware of it. But in some other comment he says that he is not sure so I can't take it as granted.

[NiBe]

Originally Posted by Lozza47

maybe give it bit of time - run a new tank of gas and get the adaptations set up then check back in?

I think that too.

It is now 3 cold starts later.

Start1:

Start2:

Start3:

I think that it is OK. You can see a little hesitation (small jump up and down in rpms) but I think that it is OK. After looking at this problem for such a long time I little bit lost a sense for what is normal or not Can anyone confirm that it is OK aka normal please? When I started this thread it was much much worse like in the OP (but that video is not mine). It is still not even one tank since I lost the adaptations.

[NiBe]

Well, cold start 4....

On Friday I'm going to change ICV. Not sure that it is the real culprit so we will see...

[Tommysalami]

Maybe something related to the secondary air system if it only happens during cold start? I've been having a stuttering idle at the end of the cold start period for a while now and only just recently got a code (27B0) for secondary air valve stuck closed. Could be something related to carbon buildup in the secondary air ports and valves. Gonna change the valve and check how things look in the ports, if they're clogged with soot, but it'll have to wait a few weeks.

Things that have already been replaced: ICV, plugs, injectors, low pressure fuel sensor, secondary air flow sensor

[NiBe]

Originally Posted by Tommysalami

Maybe something related to the secondary air system if it only happens during cold start? I've been having a stuttering idle at the end of the cold start period for a while now and only just recently got a code (27B0) for secondary air valve stuck closed. Could be something related to carbon buildup in the secondary air ports and valves. Gonna change the valve and check how things look in the ports, if they're clogged with soot, but it'll have to wait a few weeks.

Things that have already been replaced: ICV, plugs, injectors, low pressure fuel sensor, secondary air flow sensor

Thanks. I'm going to change the ICV. You did it also I actually had a plan to do it as a preventative maintenance as ICV is a frequent source of problems. But I do agree with the idea that it should be related to secondary air system such as the secondary air valves. So if ICV will not help then I will change them. Do you have any idea why this all started after the DME upgrade?

[Tommysalami]

Originally Posted by NiBe

Thanks. I'm going to change the ICV. You did it also I actually had a plan to do it as a preventative maintenance as ICV is a frequent source of problems. But I do agree with the idea that it should be related to secondary air system such as the secondary air valves. So if ICV will not help then I will change them. Do you have any idea why this all started after the DME upgrade?

To be fair, my ICV was changed 40k miles ago, when it had about 50k on it. So it could have gone bad again for me, I'm not sure.

My cold start problems all started after I changed plugs (old ones had 40k by that point). Not sure why, maybe adaptations changed just enough that the system now became sensitive to whatever else was wrong. And I've done plugs again since then so they weren't the issue. Also, seems like any time I've changed one of those components like the injectors or fuel sensor, the problem temporarily goes away. Maybe the software is adjusting, like its running in an open loop until the adaptations are done, and isn't sensitive to the secondary air system at that time. Then the problem comes back after a few starts.

[Lozza47]

Originally Posted by NiBe

Well, cold start 4....

On Friday I'm going to change ICV. Not sure that it is the real culprit so we will see...

So this is EXACTLY what my car was doing for the first 6 months since ownership - I created a thread surrounding it here:
https://www.m3post.com/forums/showthread.php?t=1875920

However, my DME was running at the factory production date software level, and even after updating to 241e it was doing the same thing (and adaptations reset).
After some more waiting, eventually it just got better. The only significant things I did during the time of it disappearing were:

- Changed from Shell V Power fuel to BP Ultimate
- Replaced thermostat as it was stuck open
- Took it to the track quite a number of times (italian tune up haha)

Also, are you running cats?

[NiBe]

Originally Posted by Tommysalami

To be fair, my ICV was changed 40k miles ago, when it had about 50k on it. So it could have gone bad again for me, I'm not sure.

My cold start problems all started after I changed plugs (old ones had 40k by that point). Not sure why, maybe adaptations changed just enough that the system now became sensitive to whatever else was wrong. And I've done plugs again since then so they weren't the issue. Also, seems like any time I've changed one of those components like the injectors or fuel sensor, the problem temporarily goes away. Maybe the software is adjusting, like its running in an open loop until the adaptations are done, and isn't sensitive to the secondary air system at that time. Then the problem comes back after a few starts.

Mine has 50K miles. So I think that replacing it will not be a mistake even if it will not be the root cause. But I'm prepared that it will change nothing But at least I can then remove it from the equation and move forward.

[NiBe]

Originally Posted by Lozza47

So this is EXACTLY what my car was doing for the first 6 months since ownership - I created a thread surrounding it here:
https://www.m3post.com/forums/showthread.php?t=1875920

However, my DME was running at the factory production date software level, and even after updating to 241e it was doing the same thing (and adaptations reset).
After some more waiting, eventually it just got better. The only significant things I did during the time of it disappearing were:

- Changed from Shell V Power fuel to BP Ultimate
- Replaced thermostat as it was stuck open
- Took it to the track quite a number of times (italian tune up haha)

Also, are you running cats?

I'm using the same fuel and the same fuel station my whole ownership of the car. Never noticed any issue during cold start. But then I updated DME and this started and it is there (to some extent) permanently every cold start. I also had to replace secondary MAF as it was throwing errors (after DME upgrade) also every cold start. So there has to be a relation to the upgrade or to the fact that it failed first and I lost adaptations.

Everything stock on the car. Exhaust is M Performance (I bought it like that). When you change stock exhaust to M Performace is there any coding required? I already looked it up and found that no, no coding required. My idea was that DME is confused because it does not know that it has M Perfromance exhaust (coding lost during the DME failed update).

[Lozza47]

Originally Posted by NiBe

I'm using the same fuel and the same fuel station my whole ownership of the car. Never noticed any issue during cold start. But then I updated DME and this started and it is there (to some extent) permanently every cold start. I also had to replace secondary MAF as it was throwing errors (after DME upgrade) also every cold start. So there has to be a relation to the upgrade or to the fact that it failed first and I lost adaptations.

Everything stock on the car. Exhaust is M Performance (I bought it like that). When you change stock exhaust to M Performace is there any coding required? I already looked it up and found that no, no coding required. My idea was that DME is confused because it does not know that it has M Perfromance exhaust (coding lost during the DME failed update).

Try a different fuel. Cold start cycles run very rich, so amongst other suggestions in this thread, could also be fuel related.

Coding is not required for the exhaust.

[NiBe]

Cold start5:

She apparently has a sense of humor..

Anyway she is in shop now - Autosolutions SSK being installed and ICV being replaced. Wish me luck

[NiBe]

For the sake of completeness. It was the Idle Control Valve (ICV). I'm now +- 10 cold starts after replacement of ICV (including 6 months cold start after winter storage) and the issue has been eliminated completely. Thanks everyone for help!

Btw I think that this means that the 241E DME software is more demanding on hardware of ICV and MAF for secondary air pump than the 2008 original version of DME software. It actually makes sense because the difference in idle with 241E is very noticeable - much much smoother maybe too much smooth as I kind of miss the 2008 roughness it had character

[Ximian]

I had the same jumping rev issue with no codes so I replaced the fuel breather valve. Then I started having a misfire in all 8 cylinders that wouldn't go away until I replaced the ICV. Don't let it get to that point, it was rough.

Not a cheap part and it seems there are no rebuild options for it.