Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: jtypecav on 16 December 2013, 16:57:11
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Right.
Today got cruise stalk and switch installed. Went to dealer and paid £30 to have the ECU told it's a manual again (remember that "faulty" ecu fixed by installing auto ECU last year?).
Cruise worked flawlessly on the way home. Until I revved to 4K, at which point the EML lit and the car killed two random cylinders (across both coil packs usually..)
This horrified me, as it was return of the problem that couldn't be identified last year. Basically, the car when correctly identified as a manual drives fine until 4K under load. In first gear, or de-clutched it will rev right round, smooth as anything.
If you rev to 4k you loose 2cyls, if you can struggle to 4k again you loose another two!!
But when designated as an auto (which we did by accident when I swapped the original out for an auto last summer - leading me to believe it was a faulty ECU!), the problem comes back again!
It's had crank sensor (difficult to get to one), and new coil packs recently.
I have to drive it 3K miles in less than a week, so have had to put it back to auto, now with the spanner lit up as it's looking for an autobox it doesn't have (but is driving fine!).
The dealer said it could be a software glitch and to check if there was an SBS for the car or similar and said they hadn't seen anything like this before and they are normally bullet proof!!
Help!
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Me thinks you need to chat to fuse 18, 2woody or serek. They the auto to manwell experts. Check all the earths, believe there's one wire you have to earth out from auto to manwell conversion.
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Thanks for the quick reply. However, the car was manual from factory, and unless I can get the spanner off I can't use cruise, it's not a conversion. Just something we fixed with an ECU that happened to be an auto. Turns out to be key to the issue!
What does a manual take account of that an auto doesn't?
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Clutch switch?
Did you read the codes when it was playing up?
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Was doing it before clutch switch was fitted back when I bought the car.
Read codes, no codes listed(!) Gives generic / multiple random misfire.
Can't diagnose again now as went back and had it set from manual to auto again. :(
No cruise now either :( (which worked flawlessly till I hit 4k revs!)
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I watch with interest, shame you're not closer, as I'd love to get my teeth stuck into one like this.
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Ah shit, except I don't have a Tech2 anymore :'(
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Right now, I'll take time off work and drive anywhere that can sort it!!
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What about ABS?
Are the tractions profiles different for auto / vs. manual?
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What about ABS?
Are the tractions profiles different for auto / vs. manual?
Doubt it. ABS will attempt brake first, then simply ask engine to reduce power.s
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The thing is, I can't even diagnose it as I've had to get it switched back to auto, so it doesn't kill cylinders off. So basically I'll have to pay vauxhall to make it not run properly again when I'm back from Europe. But *REALLY* wanted to be able to rest my right foot after 18 hours... :-\
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Struggling to make sense of the original post. When you say the problem comes back when designated as an auto - should that not be it goes away when designated as an auto?
Also you say you've had crank sensor replaced - the difficult to get to one, there is only one crank sensor but the way I've interpreted the post its as if there are multiple crank sensors.
Has this problem always existed during you ownership?
Auto's have a kick down feature which manuals don't. I've no experience of coding from auto to manual (yet) so don't know how much relavance there is in the kickdown but on A DBW system the Engine ECU must send the signal to the Gbox ECU to kick down
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What is the ABS programmed for (auto/manual)
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Sorry for any confusion.. on laptop now not phone..
The problem goes away when erroneously told it's an auto - the spanner comes on, and it drives beautifully.
When it's told it's a manual, which it's always been since factory, it behaves like described, killing injectors (I guess) at 4k. Yup, it's always behaved like this, I'll find the original thread.
I changed the crank sensor down the back when first trying to get to bottom of this. Any more q's I'll reply to asap!
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What is the ABS programmed for (auto/manual)
I only swapped out the ecu completely with ring and chips, didn't change anything else when it resolved the problem (but lit the spanner) originally.
So guessing manual still, but car drives fine with wrong ecu. Only starts playing up when told what it really is! (The master tech tried FULL conversion and partial designation - not sure what this meant, but only full designation back to auto got rid of the gremlins again..)
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Can someone modify my first post to say that it goes away when designated an auto.
Many thanks!
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(The master tech tried FULL conversion and partial designation - not sure what this meant, but only full designation back to auto got rid of the gremlins again..)
Sounds like a bit of Billy Bull. Certainly not the terminology used on Tech2 or TIS.
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Think he used the term designation - Something to do with just the engine vs. the whole system.
But agree, was hoping for more of an idea...
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Think if this was my car and I was keen to try and sort it on my own, given what you've already replaced I would get a known good manual ECU and go through the coding. Expensive for you as you've got to pay someone for the coding, or replace the thing as an ecu kit.
The car should not be killing off random cylinders with any coding. Can get you some wiring diagrams for auto vs. manual if you need them.
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The I see where you are coming from. I had thought the same too. The thing is..
The auto ECU was a known good one. It seems crazy to think that when reprogrammed as a manual that it replicates an ecu I binned over a year ago and the fault still be with this separate ECU. It's got to be something else.
If it helps, the calculated engine load on live data is all over the place. But when tested individually the thottle pedal / butterflies are accurate.
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If it helps, the calculated engine load on live data is all over the place. But when tested individually the thottle pedal / butterflies are accurate.
Can you get live data readings on the MAF?
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I will certainly have a go. But I've been thinking.. ( :-X )
If the difference is between auto and manual. Physically, what connections / sensors do each of them have. Because in both cases the main car ECU *would* be expecting data. So auto ecu expecting a gearbox ecu the throws up spanner coz all data from there is missing... but... what if the manual gearbox has something like a sensor that's true faulty state is being hidden behind the autobox ECU so:
a) with manual ecu faulty signal is sent from something on the gearbox (speed?) and received badly
b) With auto ecu the mig just shrugs saying I've not received anything from the gearbox and carries on!
Thinking logically, that's the only direction the fault can lie in. So what data comes from gearbox on both transmissions? Anything that a missing GB ECU would inhibit that a manual GB receives must be the issue.
Tell me there's a speed (or other) sensor on the gb the ecu gives a damm about??! That when removed from equation the car ignores and continues to function?>!!
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Thinking about your last post .. and a previous one ... you said that when you go AUTO the car "works" fine but the EML light is on ... what code is the EML giving ?? because that "might" be the signal that is missing/faulty ?? EML code only appears when a fault is detected ....
"The problem goes away when erroneously told it's an auto - the spanner comes on, and it drives beautifully."
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It would be helpful if it did, but it just registers a generic misfire, occasionally also detailing cyls 3 and 6. (from memory)
It also doesn't store any code once ign is off and on again.
Just thinking what could mess the load values up... had assumed the speed was from abs... but.. gearboxes "do" motion.. but it could be something else.. whatever it is.. the missing auto ecu could be shielding this from getting through to the main car ecu - whatever it is, that's the reason it runs sweet!
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(http://i.ebayimg.com/t/Vauxhall-Omega-00-03-2-2dti-manual-gearbox-only-84k-3-2-BREAKING-WHOLE-CAR-/00/s/MTIwMFgxNjAw/$(KGrHqJ,!noE8YJtNFO0BPHrn5pgng~~60_58.JPG)
I've noticed on the how-to section, and on this box here that "5) Remove the electrical connector at the back of the gearbox."
Anyone know what that's for? Was assuming that reverse switch would be in linkage / or gaiter area. If not, apologies for my lack of savvy here.
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Thinking about your last post .. and a previous one ... you said that when you go AUTO the car "works" fine but the EML light is on ... what code is the EML giving ?? because that "might" be the signal that is missing/faulty ?? EML code only appears when a fault is detected ....
"The problem goes away when erroneously told it's an auto - the spanner comes on, and it drives beautifully."
It will be something along the lines of lost communication with gearbox module, or service light on at the request of gearbox module, or control module not coded etc.
I had a look on the wiring diagrams before and the abs and auto box and steering angle sensor all share the same pins on the engine ecu. Speed signal on a manual will come from abs, speed signal on an auto could come from the prop shaft or the abs.
Would be interesting to pull abs fuse and see if the speed signal still arrived on the auto.
All this is speculative though as first and foremost is establishing WHY the cylinders drop out and how, is it actually the ignition timing, ignition itself or injector?
My plan of attack would be to find that first. If cylinders are losing fuel or spark that's a massive fault and completely undesirable state of affairs. NOTHING should do that, only on the over-run should the injectors drop out. Sparks should never drop out if the rest of the system is healthy.
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I've noticed on the how-to section, and on this box here that "5) Remove the electrical connector at the back of the gearbox."
Anyone know what that's for? Was assuming that reverse switch would be in linkage / or gaiter area. If not, apologies for my lack of savvy here.
Rear most sensor is output speed. Gearbox needs that to know when to change gear.
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Does a manual ECU still hear "gearbox speed" signial..
because.. if it does... I've listed all the things GM TCU's "typically" take in:
Input parameters[edit]
The typical modern TCU uses signals from engine sensors, automatic transmission sensors and from other electronic controllers to determine when and how to shift. More modern designs share inputs or obtain information from an input to the ECU, whereas older designs often have their own dedicated inputs and sensors on the engine components. Modern TCUs are so complex in their design and make calculations based on so many parameters that there are an indefinite amount of possible shift behaviours.
Vehicle speed sensor (VSS)
Wheel speed sensor (WSS)
Throttle position sensor (TPS)
Turbine speed sensor (TSS)
Transmission fluid Temperature sensor (TFT)
Kick down switch
Brake light switch
Traction Control System (TCS)
Cruise control module
And from that VSS and WSS seem most likely problem. Car sees WOT and no speed... goes into limp?
The spanner is only on due to missing autobox TCU correct!
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Engine, Gearbox ECU and ABS system are connected by a CAN link (steering angle and yaw sensor are sometimes shown, but they are only present on Omegas with ESP, and I've never seen that on a UK car).
If the devices detected on the CAN link are not consistent with the ECU config then errors will be raised.
ABS system measures vehicle speed and this is routed to other systems as a separate square wave signal. IIRC, it doesn't go to the autobox. This has its' own output shaft signal, as said, and gets input speed from engine RPM via CAN. It may also get vehicle speed via CAN, of course.
The fault really sounds like the engine ECU going into limp home for some reason, as it's odd to get a misfire starting at 4k RPM.
Can't think what it might be, though. ABS system not happy, perhaps? I could see it going into such a state if ABS and TC are known not to be functional due to a misconfigured CAN bus, for example, but you'd get the ABS and TC lights on then, surely?
It really needs a few hours with a Tech2, as has been said. Happy to oblige if you ever pass Hampshire... :-\
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ABS and TCS working fine (with latter switch-able!). But vehicle load... How is this calculated? On auto ECU it's correct, on manual ECU it's wrong. With auto designation there is never, ever, ever, limp or performance loss? I don't think it's 4k per se. More a perceived load / speed conflict.
THIS: Is 1st / 2nd gear map from last year. (look at EML blinking and right before for any clues?)
http://img440.imageshack.us/img440/506/1stgeargood2ndgearbadsp.png
Here's the rather redundant original thread: (yes I've driven it for a year+ with the wrong ecu till now!)
http://www.omegaowners.com/forum/index.php?topic=104473.0
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Are you sure its can? Looks more like twin k lines or a k and l to me.
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Should have added.. At the bottom of the image is where it get's weird..
At WOT - and passing the 4K barrier - engine load is 23%?!
Why couldn't it calculate load properly?
Why was anything past 49% of throttle "invalid"
Why did speed pulses appear and dissapear? Pfft.
This is all running on the original manual ecu.
The auto ecu given manual designation gave nearly identical.
Not plotted the auto as auto though!
Kevin - thanks for the offer - if you were the hampshire by Somerset I'd have already been down. But you're a bit further afield.. *goes to google maps* suddenly 1.43 aint too shabby.
I blame the taste of cruise control for the first time!!
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Have you got the original csv file from "My Naff Code Reader"?
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I've noticed on the how-to section, and on this box here that "5) Remove the electrical connector at the back of the gearbox."
Anyone know what that's for? Was assuming that reverse switch would be in linkage / or gaiter area. If not, apologies for my lack of savvy here.
Rear most sensor is output speed. Gearbox needs that to know when to change gear.
Not on a manual box ;D
Only one wire for the reverse switch :y
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Cruise control might be coincidental if the clutch switch wasn't fitted correctly... get the locking tab wrong and the switch fails after a couple of miles. A new switch should cure that issue.
If the ecu is registering a permanent clutch issue then it might be limiting the rpm to protect the clutch/dmf.
By telling the ecu it's in an automatic it ignores the clutch switch, but puts the spanner light on out of confusion...
Fit a new genuine clutch switch and report back :y
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Have you got the original csv file from "My Naff Code Reader"?
Cheeky edit there by someone. I think "My Naff Code Reader" is one of the best out there for cost vs functionallity, and beleive me, I've spent thousands on diagnostic gear.
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Have you got the original csv file from "My Naff Code Reader"?
Cheeky edit there by someone. I think "My Naff Code Reader" is one of the best out there for cost vs functionallity, and beleive me, I've spent thousands on diagnostic gear.
If it's the one I think it is, the issue is not for discussion for legal reasons :y
(Black and white in the forum rules)
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Have you got the original csv file from "My Naff Code Reader"?
Cheeky edit there by someone. I think "My Naff Code Reader" is one of the best out there for cost vs functionallity, and beleive me, I've spent thousands on diagnostic gear.
Its an auto "edit" as that equipment can't be discussed here :y
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Are you sure its can? Looks more like twin k lines or a k and l to me.
Just looked at the wiring diagram again, it is CAN, I stand corrected.
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Issue was occurring before I fitted the cruise switch (18 months ago, never had one from factory) and it's a genuine one that's been fitted, properly and still passes open/closed test.
Will take a look for the data from last year too.
Since last night I've been thinking. I know it's the injectors being turned off and the only thing that can do that is TC.
On autos the gearbox ecu has to know vehicle speed and everything else is engine related - throttle pedal, engine speed, even cold start so it leads me back to the whole what would be being held back by the lack of autogearbox ecu, or what does an auto ecu not care about that a manual does. I'm guessing it is canbus style (this link anyway!) *edit* just noticed your confirmation of this.
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Vehicle speed comes from the ABS ecu as an average of all four wheel speeds :y
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I wonder if there's an issue with the drive-by-wire throttle?
Although I've seen throttle position reported as "invalid" on logs from that code reader before - on a perfectly serviceable car. Throttle position is probably interpreted differently for an auto box, as there's a section of throttle travel for kickdown (in fact - do manual cars have a different pedal position sensor without the kickdown detent?).
I my experience, though, DBW throttle issues result in specific fault codes and a very restricted limp-home (i.e. you get about 1500 RPM - or even just idle!)
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We changed the pedal assembly last year incase that was faulty due to this - so that part of the FBW system is OK at least.
We changed the butterfly out as well (at the same time as the pedal) and the exact same problem persisted.
Is there another part of the FBW system I've overlooked? Interesting about auto ecu being more care-free about certain data aspects though as that is clearly a symptom here.
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If the pedal and throttle are from auto cars then that won't help...
That said the throttle body is identical manual/auto... where did the pedal come from :-\
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Plenty of cars have been converted to manual without throttle issues, and I doubt anyone would have changed the pedal position sensor. :-\
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Both are stock 2.6 manual, but parts were "borrowed" from a 3.2 auto - part no's were the same on both.
Assuming due to lack of codes whatever it is is throwing up inconsistent / erroneous readings, rather than not at all as car is not producing codes.
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Plenty of cars have been converted to manual without throttle issues, and I doubt anyone would have changed the pedal position sensor. :-\
Hadn't considered that :-[
Have you tried a different manual ecu/loom?
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So if you know its the injectors, then how is it occuring? A complete switch off or a reduced duration on the two affected cylinders, does your lambda sensor report lean conditions on each bank during the fault - to back up the injectors being turned off.
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It looks in the log as if the throttle position is returning to closed, assuming the driver didn't come off the gas as soon as the EML started flashing.
Injectors is unlikely, IMHO, because they are completely independent and any errors in the wiring are picked up by the ecu's internal monitoring. Yes, one injector could fail, but the engine would continue pulling with a misfire and you'd get a misfire code and (if it's electrical) an injector circuit code. Multiple/all injectors failing at once would be unlikely.
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Are you sure its can? Looks more like twin k lines or a k and l to me.
Yes its CAN, came about when the engine design was updated for the latest Euro 3 specs, the ECU type changed and GM were fitting CAN equipped ECU's in preperation for the Vectra C (which started off partial CAN e.g. engine, box, ABS etc and then full CAN) and the use of the 3.2 in the US market (Caterra and early CTS). In addition, it allowed a later gearbox ECU to be used and supprted the CAN variant of Bosch ABS unit which had additional featuers such as full ESP (with additional sensors added).
The specific variant can be run full CAN (clearly not on the Omega) or partial as per the Omega with firmware changes.
My concern is that there has been some T2 work done since and we have no idea what exactly was changed.
If your near Nottingham at any time I can plug in and see.
On the 4k limit, we know of plenty of sensors that can cause a limp mode to kick in, what we dont know is if there are other external interfaces to the ECU that can do the same (e.g. if its not been correctly configured fully to auto is there a speed missmatch between ABS and auto speed signal that can do it?)
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Given engine load is suspect, I'd be checking MAF against a known good. That said, I've seen the Naff code reader misread live data (not pinned it down, might be if too many measuring blocks selected, or piss poor laptop).
If you every pass Alton, Hampshire or Nottingham, I'd take up the offers made above by Kevin Wood and Fuse18, both know how to use the diags equipment.
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Thanks everyone. As soon as it's back from another mammoth run to Europe it'll be paying a visit to Hampshire as soon as it's convenient!
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Just to throw another variable into the mix (though I don't set much store by it) does the operation of the multiram system differ between auto and manual differ?
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Just to throw another variable into the mix (though I don't set much store by it) does the operation of the multiram system differ between auto and manual differ?
I don't believe so
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have you considered torque reduction request at gearchange ? a feature of auto only.
you really need to ascertain if the misfire is caused by the Traction Control function of the ABS. If its only two specific cylinders, then I suspect not. But if, however, its a random cylinder cut, then I'd believe so. Does the TC lamp flash when its misfiring ?
There are very few ways in which the transmission ecu could cause a rev limit to be applied. In fact, I can't think of any at all.
I have a spare manual 2.6 siemens ecu and chip, etc if you'd like it
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Lamp doesn't flash, but is two random cyls, normay one each bank. The revs are not limited, its just far harder to get there!
Remember the bizarre do it once loose two cyls, do it again and loose another 2 on top of the first two! Yes, it tries to run on two for a second then dies, I bet if it'd run on 2 do it a 3rd time and it'd drop to zero!
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Do you have the csv file?
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Just re read most of this..
so you have a car that is not 100% you've known about it for a while and your going to take it on a 3000 odd mile jolly across Europe? ::)
is it me.
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Just re read most of this..
so you have a car that is not 100% you've known about it for a while and your going to take it on a 3000 odd mile jolly across Europe? ::)
is it me.
What could possibly go wrong ::)
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It's done it twice before so far!
18 months ago I fitted an auto ecu and it's driven lovely since. So no reason to think it wont continue to. ;D Only reason this all came up was because I wanted to enable cruise, and needed it to be a manual ecu again to work! Didn't think it'd come back on a completely different ecu, when all that changed was the designation. So it's been put back to auto and driving fine since. But on return it's getting sorted!!!!
Plus I've taken all my tools!
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Basically, the car when correctly identified as a manual drives fine until 4K under load. In first gear, or de-clutched it will rev right round, smooth as anything.
If you rev to 4k you loose 2cyls, if you can struggle to 4k again you loose another two!!
I see why TB is curious about the mass flow readings now. Whatever it is seems to be related to the apparent load. Cut two cylinders and the apparent load will increase because 1/3 of the air passing through the mass flow sensor is being pumped through the dead cylinders.
I assume you checked for fuel starvation last time this issue occurred.........
Posted by: AndyStobbs Yesterday at 20:57:16 »
Just to throw another variable into the mix (though I don't set much store by it) does the operation of the multiram system differ between auto and manual differ?
Rear multiram opening occurs at about 4K IIRC. Can't see why auto should be different to manual but I wonder if the solenoid is faulty or a trapped wire is shorted somewhere :-\
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You can see multiram operation in the datalog (Intake valve 1/2) and they do operate normally a few times before the fault occurs. :-\
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Shouldn't kill cylinders no matter how bad the wire is. We haven't got to the bottom of how the cylinders are failing yet though. That log file is missing all the useful sensor data.
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Shouldn't kill cylinders no matter how bad the wire is. We haven't got to the bottom of how the cylinders are failing yet though. That log file is missing all the useful sensor data.
The rev-limiter on the V6 ECUs works by cutting cylinders - normally somewhere above 6500 rpm
If there is a current fault code then the rev limit drops to 4000 rpm so we are working on the assumption that the ECU is cutting cylinders.
My naff code reader isn't discussed on here because it isn't legally available in the UK (only pirate copies) and we don't want any lawyers trying to shut the site down.
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Going by what Andy has just posted ..... rev limiter .. is that "adjustable" via Tech2 program ??? If it is ... is there a "chance" that the Rev limiter has been set at a "wrong" value ??
Or are the manual ECU's "missing" a rev signal and "assuming" its reached the rev limiter at 4000 rpm ?
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Will look out the laptop tomorrow to see if it has any of the files still.
As for limiter.. I wouldn't mind a rev limiter, or something that felt like one. This properly goes permanent misfire like when a coil pack goes!
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Will look out the laptop tomorrow to see if it has any of the files still.
As for limiter.. I wouldn't mind a rev limiter, or something that felt like one. This properly goes permanent misfire like when a coil pack goes!
So once it loses two cylinders they don't start firing again?
Do they come back immediately if you stop & restart the engine?
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Once they are gone they are gone. They don't come back till you ign off and start again.
The bizarre behaviour is above 4k loose 2 cyls, then struggle up to 4k again (whilst running only on 4) and you loose 2 more (and it's trying to run on 2 cyls!)
Off and on again and it's back on 6, no matter what circumstances - happy as larry till you dare rev it again. Or as an auto it pulls strongly to the redline!
*edit* I say 4K - it's pretty much there, but couldn't say whether it's just reaching some threshhold or actually rev related, but it has a 100% reproduction rate.
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Once they are gone they are gone. They don't come back till you ign off and start again.
*edit* I say 4K - it's pretty much there, but couldn't say whether it's just reaching some threshhold or actually rev related, but it has a 100% reproduction rate.
The fact that that it resets after cycling the ignition points very strongly to a software/firmware issue in the ECU. Something unexpected triggers the stage 1 rev limiter but nothing 'untriggers' it afterwards. Do it again and stage 2 is triggered.
We don't have access to the source code for the ECU so we cannot check for 'unexpected' triggers, it might be a properly useful piece of protective code but it does appear to be a bug that is only exposed when the ECU is coded for manual transmission.
Have you checked the battery/alternator voltage when things are getting weird?
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Hi Andy, that's the long and winding path my limited reasoning took originally. I hadn't checked the voltage at the same time. I think that both ecu's are good, so I binned a "broken one".. :'( months back.
Were there ever any critical software updates for that engine? It was running factory version apparently. I bought her with 60k on, although it would be crazy if the old boy had never got it to 4k!!
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IIRC, Taxi Al had a very similar issue to this.. on a Manual 3.2.
Can't remember what fixed it in the end. :-\
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Kevin - don't tempt me to spent hours searching the forum!! ;)
Here are two original live data captures from start till EML blinking taken when I first experience the same problem 18months ago.
6 >> 4 cylinders: https://dl.dropboxusercontent.com/u/2011453/ECU_Good_to_Bad_Livedata_2001_Omega-B_Engine__Y%2026%20SE_201206261444.xlsx
4 >> 2 cylinders(!):
https://dl.dropboxusercontent.com/u/2011453/Bad_to_Terrible_Livedata_2001_Omega-B_Engine__Y%2026%20SE_201206261450.xlsx
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IIRC, Taxi Al had a very similar issue to this.. on a Manual 3.2.
Can't remember what fixed it in the end. :-\
Two coil packs, two engine looms and alot of head scratching :y
Alot of bits were swapped in the process, only significant item was a year old pattern MAF was replaced with the original one (which is still fitted)...
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Has anyone with a scope looked into this yey? Or has it all been done on live data?
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Just live data, the injector testing was done by a friend who was a Vauxhall mechanic for years, same chap who donated 3.2 parts to this temporarily.
Fully open to a trek for a days diagnosis now!
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IIRC, Taxi Al had a very similar issue to this.. on a Manual 3.2.
Can't remember what fixed it in the end. :-\
Two coil packs, two engine looms and alot of head scratching :y
Alot of bits were swapped in the process, only significant item was a year old pattern MAF was replaced with the original one (which is still fitted)...
It was a very similar set of symptoms, though, if memory serves. Rag it up to 4K+ in 2nd and the light starts flashing and it drops a couple of cylinders?
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The threshold was lower, about 3k iirc, but same behaviour.
An auto ecu didn't cure it, so there might be some smoke/mirrors with the ecu (re)programming.
Also turning it off and on again won't work forever...
Running with the knock sensors unplugged helped, as the misfire echo caused it to lean out(iirc), making it misfire more
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The threshold was lower, about 3k iirc, but same behaviour.
An auto ecu didn't cure it, so there might be some smoke/mirrors with the ecu (re)programming.
Also turning it off and on again won't work forever...
Running with the knock sensors unplugged helped, as the misfire echo caused it to lean out(iirc), making it misfire more
The ECU takes a signal from the MAF to calculate how much fuel to inject. If the pattern mass flow sensor reached full scale when the engine was only partially loaded then the ECU wouldn't be aware of any additional load above that mass flow rate. More load (aka intake air) without any extra fuel is going to end in tears.
Jtypecav's MAF doesn't seem to be as sensitive as ex taxi al's but both are too sensitive for the V6.
Running without the knock sensors means that the ECU doesn't know about the pre-ignition :o
I'm guessing that the engine ECU and auto box ECU work together to reduce load if knock is starting to occur but the ECU in a manual can't do that so has to resort to extreme measures (leaving you with just enough to get to the hard shoulder)
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I think the ECU just retards timing if it detects knock. There's a knock retard variable for each cylinder visible by using a tech 2. I'm struggling to understand how the auto box would need to be involved, TBH.
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I think the ECU just retards timing if it detects knock. There's a knock retard variable for each cylinder visible by using a tech 2. I'm struggling to understand how the auto box would need to be involved, TBH.
I would agree with that. The ECU constantly pushes the timing forward until it picks up knock, then slips back.
On the MAF thing, load is a function of vacuum, revs, and air flow. A static car could be redlined in neutral and the MAF would hit its max value - or very near to, but that isn't max load, no where near infact.
A MAF that peaks before the engine can't physically use air any faster isn't going to cause massive running issues, the power will just flatline, as a balance will exist between airflow, fuel quantity and load, the engine can't continue to build revs without more fuel.
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My original MAF was replaced with a pattern one a long time prior to my issue. A MAF code cropped up a while after my issue started. Refitted original MAF and code went. Still fitted and working as required.
Changing the loom made the biggest difference, eventually solving the misfire. Only measurable detail which stood out was the voltage on one cylinder being 2/3rds of the expected value. Changing coil packs made no difference to this value.
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I think the ECU just retards timing if it detects knock. There's a knock retard variable for each cylinder visible by using a tech 2. I'm struggling to understand how the auto box would need to be involved, TBH.
If Bosch chose to they could have programmed the gearbox to drop a gear or unlock the lock up clutch in response to any signal from the engine to say that it was labouring.
I am not stating that they did, only that they might have done. Seeing as we are guessing as to why an ECU programmed for auto behaves differently to one programmed for manual it seems as good a guess as any so far.......
Back to my main point though, I strongly believe that a pattern MAF is screwing up the airflow reading causing potentially catastrophic lean running (and the ECU is throwing a hissy fit to protect the engine)
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Exactly why the rest of the data is required, if its going lean the lambda's will show it.
ex taxi al - Which voltage are you referring to?
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Exactly why the rest of the data is required, if its going lean the lambda's will show it.
ex taxi al - Which voltage are you referring to?
Coil pack to plug :y
One cylinder (6) was producing 40kv instead of the 60kv at the other 5...
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And its still the same? Could be a cylinder issue, or a lead or the plug.
The tension will only increase to the point where the air gap is ionized, a smaller air gap will conduct at a lower voltage, a less dense charge will do the same. As long as your burn voltage and times all look similar and your cylinder contributions are more or less in line then its not really important.
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For the umpteenth time changing the loom sorted my issue...
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Just to re-state the evidence......
.....engine runs well when ecu thinks its in an auto box application
.....engine runs badly when ecu has possibly (as we dont know if it was done correctly) been configured as manual
For me that all but rules out most components associated with ignition/injection/measurement etc
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Correct fuse. The factory manual ecu and a different auto ecu told to be manual produce exactly the same symptom s.
Car is manual from factory, running auto ecu at present with no performance issues.
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Has the ABS ECU been changed?
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Nope! How come?
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Because we are running out of avenues to explore and the ABS ecu shares its connection to the engine ecu with the autobox ecu.
With the engine ecu configured for auto, do you still get the drop out of VSS signal?
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The ABS ecu can cause some very funny problems when incorrectly / nor programmed. They need to know engine size and gearbox type.
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Looking forward to getting back to Blighty and getting it sorted, but the old girl has done me proud so far. Over 1000 miles today on the auto ecu and not a whimper. Currently in Poland heading for mountains. Was nasty accident in Dresden where the coolant level warning came on, but that was just a gummed up sensor from the oil coolers fail last month! Its been living up to it's autobahn storming name that's for sure!
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Right, well £500 in fuel lighter, I'm looking to get to the bottom of this. The omega will become the second car about March instead of the newest thing I own with a new thing on the way. But despite obvious advantages of MPG etc we have decided that Kat's MK4 astra will be going on to pastures new instead.
I'm hoping that sorting this out might give me a couple more mpg though. With winter stickies on she averaged 26mpg over 2000 miles of motorway! That's the same I get around the lanes pretty much. Didn't miss a beat the whole way mind. Bar a heart in mouth moment when the coolant level warning came on during a 4 car pileup endued traffic jam near dresden when sat in stationary traffic. A quick check prooved it was just gunk from the previous oil cooler problem still in the system bunging it up!