3.0i M54 Rough idle then cuts out

[Chris_D]

it's the ccv diaphragm. am tellin ye.

 

[enuff_zed]

it's the ccv diaphragm. am tellin ye.

So why does it run perfectly when you reset it? Sounds much more electrical and less basic physics to me?

 

[Chris_D]

it's the ccv diaphragm. am tellin ye.

So why does it run perfectly when you reset it? Sounds much more electrical and less basic physics to me?

Idk. Maybe like how my knackered throttlebody would work fine when you reset it. Then on the next startup it would go kerplup and die.

Dont forget that a lot of components work fine outside of operational parameters/limits set by the dme.

 

[enuff_zed]

it's the ccv diaphragm. am tellin ye.

So why does it run perfectly when you reset it? Sounds much more electrical and less basic physics to me?

Idk. Maybe like how my knackered throttlebody would work fine when you reset it. Then on the next startup it would go kerplup and die.

Dont forget that a lot of components work fine outside of operational parameters/limits set by the dme.

Worth a look at least

 

[Rix]

How did the reflash go? Any joy?

 

[enuff_zed]

How did the reflash go? Any joy?

Still only Monday in Norfolk mate! oke:
I did say we're doing it Wednesday (or maybe Saturday to you )

 

[Rix]

Duh, ignore me!! Fingers crossed....

 

[IRD]

Martin/Stuart et al. I really enjoy reading the posts. I just wish I understood what they were all about, especially all those acronyms. I hope Wednesday is a better day weather wise than today and that all goes well.

 

[enuff_zed]

Martin/Stuart et al. I really enjoy reading the posts. I just wish I understood what they were all about, especially all those acronyms. I hope Wednesday is a better day weather wise than today and that all goes well.

Cheers.
Acronym is easy. DME is the ECU for the engine. :roll:

 

[IRD]

Martin/Stuart et al. I really enjoy reading the posts. I just wish I understood what they were all about, especially all those acronyms. I hope Wednesday is a better day weather wise than today and that all goes well.

Cheers.
Acronym is easy. DME is the ECU for the engine. :roll:

Thanks Martin. Every day is a school day. Joking apart. It is impressive to see the range of knowledge and expertise available on the Forum. Imagine what the cost would be if you had seek help from a main dealer.

 

[enuff_zed]

Martin/Stuart et al. I really enjoy reading the posts. I just wish I understood what they were all about, especially all those acronyms. I hope Wednesday is a better day weather wise than today and that all goes well.

Cheers.
Acronym is easy. DME is the ECU for the engine. :roll:

Thanks Martin. Every day is a school day. Joking apart. It is impressive to see the range of knowledge and expertise available on the Forum. Imagine what the cost would be if you had seek help from a main dealer.

More cost and probably less idea :rofl:

 

[enuff_zed]

Well I have bad news dammit!
Despite Stuart's best endeavours we cannot fix this motor.
I managed to reproduce the fact that it runs perfectly for a few seconds when you reset the faults and we are in full agreement that it is the DME. Cannot feasibly be a mechanical problem or why would it run so cleanly when you reset the electrical gubbins?
However, INPA could not even see the DME, let alone find out its software version or attempt a reflash. As far as it was concerned there was no DME in the car!
Interestingly, while we tinkering around, every minute or two we heard a click from somewhere in the locality of the DME and the fuel pump would run for a couple of seconds.

Anyway, I have invested a fair bit of time and materials into this car now so I'm not willing to break it just yet.
Next step is get the DME out and send it off to either be repaired or cloned.

Watch this space.

 

[Chris_D]

Before you quit, like a big fat quitter eating a melted slice of quit, have you tried swapping/replacing the fuel pump relay?

 

[enuff_zed]

Before you quit, like a big fat quitter eating a melted slice of quit, have you tried swapping/replacing the fuel pump relay?

Not yet, but why would that reset when I clear the codes? And we can hear the pump running too.

 

[Chris_D]

Before you quit, like a big fat quitter eating a melted slice of quit, have you tried swapping/replacing the fuel pump relay?

Not yet, but why would that reset when I clear the codes? And we can hear the pump running too.

Who knows?
But it's worth a look and easy enough to check isn't it?

 

[enuff_zed]

Before you quit, like a big fat quitter eating a melted slice of quit, have you tried swapping/replacing the fuel pump relay?

Not yet, but why would that reset when I clear the codes? And we can hear the pump running too.

Who knows?
But it's worth a look and easy enough to check isn't it?

Never rule anything out.

 

[Rix]

Well I have bad news dammit!
Despite Stuart's best endeavours we cannot fix this motor.
I managed to reproduce the fact that it runs perfectly for a few seconds when you reset the faults and we are in full agreement that it is the DME. Cannot feasibly be a mechanical problem or why would it run so cleanly when you reset the electrical gubbins?
However, INPA could not even see the DME, let alone find out its software version or attempt a reflash. As far as it was concerned there was no DME in the car!
Interestingly, while we tinkering around, every minute or two we heard a click from somewhere in the locality of the DME and the fuel pump would run for a couple of seconds.

Anyway, I have invested a fair bit of time and materials into this car now so I'm not willing to break it just yet.
Next step is get the DME out and send it off to either be repaired or cloned.

Watch this space.

Thanks for the update - disappointing but another bit of investigating compete. Weirdly I have the same issue insofar as my cheap code reader cannot see the DME and wondering whether to get mine sent away. I opened mine up at the weekend and couldn't see anything physically damaged in it. I multimeter tested the mosfets which seemed ok but that was the end of my technical skills! Have you got somewhere in mind for where to try to get it repaired? https://www.actronics.co.uk/ get recommended on the UK salvage YT channel but they seem to only deal with the trade.

Edit, I also checked the fuel pump relay (behind the fuse box) and the two relays in the DME box - I think one does the DME itself, and also jumpered the relays to see if that helped. Still no start at all for me!

 

[enuff_zed]

Well I have bad news dammit!
Despite Stuart's best endeavours we cannot fix this motor.
I managed to reproduce the fact that it runs perfectly for a few seconds when you reset the faults and we are in full agreement that it is the DME. Cannot feasibly be a mechanical problem or why would it run so cleanly when you reset the electrical gubbins?
However, INPA could not even see the DME, let alone find out its software version or attempt a reflash. As far as it was concerned there was no DME in the car!
Interestingly, while we tinkering around, every minute or two we heard a click from somewhere in the locality of the DME and the fuel pump would run for a couple of seconds.

Anyway, I have invested a fair bit of time and materials into this car now so I'm not willing to break it just yet.
Next step is get the DME out and send it off to either be repaired or cloned.

Watch this space.

Thanks for the update - disappointing but another bit of investigating compete. Weirdly I have the same issue insofar as my cheap code reader cannot see the DME and wondering whether to get mine sent away. I opened mine up at the weekend and couldn't see anything physically damaged in it. I multimeter tested the mosfets which seemed ok but that was the end of my technical skills! Have you got somewhere in mind for where to try to get it repaired? https://www.actronics.co.uk/ get recommended on the UK salvage YT channel but they seem to only deal with the trade.

Sent a few queries to some of the companies that advertise repairs etc. I'll see what comes back.
Have already, through the wonders of the forum, found a replacement DME should I need it.
Very interested in the suggestion that you can disable the vin-specific parts and simply 'plug and play'. Something that bigwinn is looking at more closely.
You need to x-ref to this thread too for the full discussion:
https://z4-forum.com/forum/viewtopic.php?t=133520

If you can hang on a bit with yours we may get some more answers for you.

 

[enuff_zed]

Mostly for [ref]Rix[/ref]'s benefit, as I know you're waiting; this is where we're at.
I stuck the DME Part Number into Realoem and found a long list of retrospectively exchangeable ones.
Barry ([ref]umfaan[/ref] had one and it is currently on it's way to me.
Stuart ([ref]bigwinn[/ref], via the other thread I linked to, has found and downloaded some software. We are reliably informed that we can put the replacement DME into the car, locate and disable the bit that runs a check with the EWS system and then it will function perfectly well in my car, probably with a reflash to ensure it is all up to date and working properly.
I think I have now exhausted every other possibility, including the hopeful straw-grabbing ones so the only step remaining after this is to throw some money in the direction of Mr Esso and Mr Swan Vesta and hope that sorts it. :roll:

 

[Rix]

Thanks for the update and yeah I hope so too! If it turns out to be the DME I'm not sure if that makes me happy or not, but obviously it would be great to have it running - both you and me alike!