Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: 05omegav6 on 31 May 2011, 10:42:12
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Had the codes read and cleared yesterday. Emission control light now back on >:(
Only 3 codes this time:
1. 0300 random misfire
2. 0306 misfire on number 6
3. 0704 clutch switch malfunction
The clutch switch is not the problem, a new one is on order and we knew yesterday that it was suspect. Does explain why the cruise stopped working on the way home ::).
The car has recently, ie in ther last 8k/3months, had both coil packs replaced with nearly new s/h ones, 6 new plugs, number 6 injector swapped with number 5 injector(made no difference).
Basically engine is idling a bit rough, though it still goes wot like it should :-/ Thinking that it might be a wiring issue, although everything is plugged in as it should be.
Fast running out of possibilities.
Al. :y
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The ECU normally picks up any breaks in the wiring and flags up a fault code, even if it's an intermittent problem. :-/
I know we went over loads of possibilities before..
I would say on the face of it either faulty ignition components, poor mixture control - MAF sensor / lambdas perhaps? or maybe the crank sensor on the way out? I think we covered all of these before, though.
You said it often gets worse after a long period of idling. I wonder if the lambda sensors are cooling off? Then again, IME the ECU will pick up problems in this area and flag them up before they affect engine running.
I suppose if the MAF was also faulty, so open loop running was poor?...
Do you have access to a code reader that can report live data? Would be interesting to see if anything is noticeably different when it starts misbehaving? (MAF output, fuel trims, O2 sensor behaviour, coolant and air temperature, injector duration, battery voltage, etc.).
Kevin
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And as a quick addition Al, don't even contemplate the LPG conversion until you've got this issue sorted and had a few clear weeks with no issues ;)
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Maf sensor was also replaced. Best I can do is the pedal trick I'm afraid. :-/
Very valid point, Paul. Whilst LPG is definitely on the to do list, it is not iminant, I've got other bits to do first such as tax bill looming, and trying to get time to do my Hgv test. The car is an ongoing project. It's taken me a few years to work out that life is easier in bitesize lumps. :y
If I can break down the collecting of parts etc ready for the conversion, then once the car is behaving itself, I'll be ready to get cracking. :y
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Was the air leak on pot 6 confirmed and rectified? ( working from a poor memory of old posts :-/. )
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Next time it starts acting up, might be worth unplugging the MAF. See if the idle improves.
Failing crank sensors are also generally worse after when a bit of heat soak has set in...
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might be worth unplugging the MAF. See if the idle improves.
Give me 2 mins :y
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Right. Unplugging MAF made no difference. just re read codes and in order:
0300
0306
0704
0303
0304
0305
0100.
If left idling it starts getting really rough quite quickly. If you then try and drive the car it bogs down at approx 1800-2200 rpm, just wont accelerate. Ignition off then on again and it drives fine until you next leave it idling for more than 30 secs. :-/
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Was the air leak on pot 6 confirmed and rectified? ( working from a poor memory of old posts . )
Compression test on pot 6 was within 10% of the other 5 pots iirc. Both sides (above and below) of the intake manifold had new seals fitted, as did the plenum. Seals were all genuine vx.
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After it starts idling rough, does it improve if you hold it at, say, 3,000 RPM for 30 seconds and then let it idle again?
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Don't know. :-/ I'll try that when I go back in to work this evening.
Generally, I just switch it off and back on again, and even this doesn't entirely sort it.
Thinking out loud mode: ON.
You mentioned about residual heat possibly affecting the crank sensor. The sensor was replaced approx 50k ago, by vx with a genuine one. Not sure about the routing though. Was the modified route a vx suggestion, or was it an OOF solution?
Two things happened around the time of this issue beginning. Firstly the aircon stopped working, secondly, the car had a full service plugs/filters/cambelt/wp.
The aircon condensor was fubar - chunks missing. Have replaced with a tidy 2nd hand one and the car is being regassed tomorrow. I usually leave the aircon switched on, which would cause the fans to run almost constantly, thus reducing the engine bay temp :-/
I wonder if this might be the thing that is causing the gremlins :-/
Thinking out loud mode: OFF
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It might be worth a look at the routing of the crank sensor wiring. Normally, the alternative route is a matter of necessity as it's all but impossible to use the original route up by the oil cooler lines. They may have managed to route it the original way, though.
In addition, however, tying the cable to hot oil cooler lines isn't a great idea from a point of view of reliability as the cable insulation breaks down with the heat.
Normally, crank sensor issues cause a code to be raised (P0335 on these IIRC), and normally the engine just stalls and refuses to restart until it has cooled a little, but, as we're clutching at straws... ;)
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After it starts idling rough, does it improve if you hold it at, say, 3,000 RPM for 30 seconds and then let it idle again?
Sadly, no. :'( If anything it's a bit worse for it.
Although whilst up at that speed, it only spluttered once, one miss on one cylinder. :-/
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Aircon regassed. Nice and cold inside 8-), still idling like a 3.5 pot >:(. Runs and drives fine provided I keep it above 1500rpm. :-/
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Thinking about it, joshwyatt had a 3.2 manual that was exactly the same... ...we never did get to the bottom of it before space demanded he sold it as spares or repairs...
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At next meet, if anyone is willing, I might be inclined to swap throttle body...
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At next meet, if anyone is willing, I might be inclined to swap throttle body...
Think it might have got to that stage. Just swap bits until something changes. :-/
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Right, thanks to Albs, new ecu, transponder and chip installed. :y
The mystery deepens... swapped the above over, no emmissions light but spanner light on ::)
Took car for a blat and goes like a train and seems to idle better :y but spanner light off after 100yds, emmissions light back on >:( arse.
Pedal tricked the codes when I got back and got the following:
in order
1. 1500 throttle failure.
2. 0120 throttle position.
3. 1612 immobiliser no signal (forgot to plug transponder in before trying to start ::) :-[).
4. 2106 CanBus failure to connect to transmission (haven't fitted the autobox so no surprise).
5. 0300 general misfire.
6. 0305 missfire pot 5. (might have mis counted)
7. 0300 general misfire.
8. 0306 missfire pot 6.
Not sure what Albs' breaker died of, so don't know what issues are new or old though some are obvious, ie gearbox.
Also got the cruise working with a new switch, but now not working again. :(
Going down to Lyndhurst tonight, so car will have a decent run to settle down. :-/
(I'm thinking possibly a wiring upset for the number 6 injector :-/)
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Breaker died of a seized bottom end. I dont have any knowledge of what problems it may have had before that though. :-/
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(I'm thinking possibly a wiring upset for the number 6 injector :-/)
Possible, although the ECU should detect that and throw up a code.
Worth swapping the injector with another pot and see if the fault moves?
Did the breaker have cruise? Could be that cruise is not configured on that ECU.
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.. and if cruise is configured, likely the auto/manual gearbox mismatch is disabling it?
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.. and if cruise is configured, likely the auto/manual gearbox mismatch is disabling it?
That was my thinking, was working fine with the new switch before I swapped the ECU. Engine probably now thinks that it's on a bench. ::)
Worth swapping the injector with another pot and see if the fault moves?
Swapped injector 6 with number 3 iirc whilst trying to investigate initial problem. Thinking that if accidently earthing that injector plug had frazzled the old ECU, possibly did the wiring at the same time. :-/
Incidently, Emissions light is still on permanently, could the gearbox mismatch do this?
Also will idle alot better that it was, even if left for 5 mins. Before was missing really badly and hunting all over the place as the ECU tried to make it idle. Now idling almost steady, only fluctuatin 50 ish rpm rather than 300 ish. Though after a while the light flashes for a 10 seconds or so ,then stays on.
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Right...
After a couple of days the car was back to its usual self, ie moody as cufk.
Worth swapping the injector with another pot and see if the fault moves?
Took the inlet manifold off, stripped the injectors off and cleaned everything, popped it all back together. No improvement. Busy working Friday night and one of the injectors sprang a leak >:( >:(
Got a complete 2.6 inlet assembly from Steve at Heathrow :y
Totally identical to 3.2 one as it happens, (compared side by side off the car). All back together, and...
>:( blockstables
Still runs rough if left idling for more than 30 seconds. switch off and on again seems to be the only cure, but that has ruled out the injectors and injector loom if nowt else. :-/ and I now have a spare manifold for lpg nozzles. :)
Can get a new engine loom for £100, so wonder if that might be the next step? Or am I on a hiding to nothing? :-/
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Worth getting it on a tech 2 to see if anything obvious is changing when it runs lumpy, IMHO. There must be a clue in the live data.. :-/
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Will just have to put up with it 'til the lakes. A poly barrel of WJ Kings' finest to the person/peeps that solve it me thinks. :y
Still managing 25mpg whilst working which is ok. :-/
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Re cruise. Breaker was an elite, and pretty sure it had cruise - Istr selling the stalk about 3 months ago.
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Will just have to put up with it 'til the lakes. A poly barrel of WJ Kings' finest to the person/peeps that solve it me thinks. :y
Still managing 25mpg whilst working which is ok. :-/
Darn! I wish I was going to the lakes. [smiley=beer.gif]
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Darn! I wish I was going to the lakes.
I'll try and save you some :y
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Have finally found the issue with this :o I think...
I've removed the plug from the 246 coil pack and attached a replacement one along with another 5" of loom. Whilst doing this I found a loose earth wire, which I have re attached.
Did a run upto Gatwick and back (26 miles) and no sign of the EML, the engine was running for approx 1hour (including a drive through breakfast).
Left the car for a bit and on restarting the light was back on >:(
Pedal trick produced 0100, 0300, 0306, 0300, 0306. :-\
So we have a general misfire, a misfire on pot 6 and an iffy MAF sensor.
Engine gone all lumpy again :'(
Maf disconnected = no difference :-\ As for the misfire returning, that could be my soldering, but might only be that light stayed out due to ECU being unplugged whilst soldering, and now readjusted itself :-\
Looks like the loom could be next for changing :-\
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Where did these coil pacs come from Al?
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I wonder what the fuel trims are doing? Removing power from the ECU would probably have cleared the fuel trims... Then again, if we've checked the live data once we've done it half a dozen times... ::)
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Where did these coil pacs come from Al?
Got them form the plce you recommended int' midlands. :-\ did try 3 different coilpacks at the lakes and all 3 were tested and produced 60,000 volts on 2 and 4, but only 40,000 volts on pot 6. So them ruled out.
I wonder what the fuel trims are doing? Removing power from the ECU would probably have cleared the fuel trims... Then again, if we've checked the live data once we've done it half a dozen times... ::)
And again at the lakes ::)
New loom in order me thinks...
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Just to update: car does seem to be idling better overall :y, no hissy fits tonight :-X, although light is still on. :-\ At least I know that the bulb hasn't blown ::).
I think that perhaps it is probably a combination of the following:
1. An engine earth being disconnected.
2. A wiring fault as a result of being laid up for 7 months, (moisture ingress), causing the voltage drop on pot 6.
3. Possible exhaust valve damage from the destroyed plug.
Next step will be the loom. The valves can wait until the head needs to come off, as I don't really want to break open the engine just yet. Still got the original MAF sensor so might try swapping that back to see if the 0100 stays, not sure how long pattern MAFs last. (Done about 30k) :-\.
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Pattern MAFs have been known to e a bit hit and miss...
Have you done a compression test? (I'm sure you have)
Just thinking that would surely offer some clues if there's physical damage.
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i think he said earlier that Pot 6 was within 10% of the others....
frankly, that piece of information bothers me.... i'd want it a lot closer than that..... if something happened valve wise previously, (assume it is somewhere in another thread) i'd strongly suspect something like a damaged valve seating , and i'm damn sure that would affect the running to some extent..... whether it would cause this issue, on it's own, i'm not so sure....
however, it strikes me that if an exhaust valve is damaged, even if it's just the seating , then the emissions light issue would make sense, as the thing will be leaking unburnt fuel mixture on compression cycle....
given that almost everything else seems to have been prodded and poked , changed, swapped, and tested, there's not a whole heap remaining....
ultimately, the holy trinity of Fuel, Compression, Spark, are what run the thing, and if it's lumpy and grumpy, there's going to be a reason affecting their relationship somewhere.....
i'm not up to date with the control systems , but in my youth i did used to build competition engines for rally use..... 10% is a LOT more variance than i would ever have accepted on a compression test.
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Of the top of my head, Pots 1-5 were 9.2/3 and Pot 6 was 8.9, so not that significant a difference :-\.
Thinking that the problem is electrical rather than mechanical because once it starts buggering about, if you turn it off and back on again, 9 times out of 10 it is fine, sometimes for five mins, and sometimes for two hours, no rhyme or reason. It just doesn't like idling when it is damp. that seems to be the only consistancy :-\
Will try the 'old' GM MAF today, as I've not gotten round to that yet ::)
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Interesting thread Al - hope you have some success later on. 8)
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Right pattern MAF swapped out with original one. Left the ECU unplugged for ten, then restarted, light out. Once warmed up light started flashing and started hunting a bit. Turned off and re checked the codes: 0100, 0300, 0306, 0304. Residual codes I think:-\
Had lunch and went for a spin, light still out, running idling OK. Will see what hgappens when I hit the mean streets tonight... :y
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http://www.omegaowners.com/forum/index.php?topic=97070.0 (http://www.omegaowners.com/forum/index.php?topic=97070.0) Might this have something to do with it :-\