Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: x1xv45 on 27 July 2013, 10:19:38
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This continues from previous post: http://www.omegaowners.com/forum/index.php?topic=115692.0 (http://www.omegaowners.com/forum/index.php?topic=115692.0)
Since then I've replaced cam and crank sensor (with known good ones from RobG), and re-cleaned throttle body with new gasket, re-checked all breathers (fine), re-checked spark plug wells for any oil or water (fine), and checked for vac leaks with carb cleaner, but couldn't find any, replaced fuel filter. The problems continue as before - very rough, really terrible at ignition, have to repeat 4 or 5 times, then starts to smooth out, then it's fine and runs great until the car sits for a few hours. Don't know what to do now.
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Hi FrankH. I am following your threads with interest, having a 2.2 behaving similarly, if less frequently.
Could it be the ECU failing? I have had one fail on a Senator, used to keep spares handy, but never read mention of ECU failure on this forum. They are full of soldered connections, which tend to crack and become intermittent with aging and vibration. Are they completely infallible on Omegas?
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Interesting idea, but it needs someone with much more experience than me to comment on it. It's nice to know someone is interested out there - I'm getting over a bit of post-crank sensor depression: after hours of bloody struggle, the satisfaction of getting it done, and then absolutely zero result!
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Tim, have you tried with MAF disconnected on initial start up
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On the Senator I could test by substition. I had 2 explod 24 valve 3 litre cars, one would not start, so I switched ECUs, and the fault switched with it. Not so easy on Omegas, with immobilisers. I wonder if it can be done by the owner driver?
My sympathy about changing the crank sensor and it not curing the fault. It's the one job that is easier on the V6 Omegas than on the straight fours. Also with changing all the bits you have changed and still having the fault. Don't despair, I am sure this forum will crack it in the end.
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Idle thought. If I switched the ECUs between two similar Omega, and transferred the immobiliser chips between keys, would they start?
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Tim, have you tried with MAF disconnected on initial start up
- just tried it: same prob, took two tries to get it running; you might say that's an improvement, but the number of tries is pretty random - I'll try again in a few hours though.
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Idle thought. If I switched the ECUs between two similar Omega, and transferred the immobiliser chips between keys, would they start?
you will need the immo ring around the keyhole on the steering..
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and as for the rough running, I have seen lots of omegas lke that.. unfortunately their problems were not as simple as sensors alone :-\
leaky exhaust, condition of valves + stem seals, injectors , lamnbda sensors , pistons rings all effect in combination.. ecu is the simplest to try..
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and as for the rough running, I have seen lots of omegas lke that.. unfortunately their problems were not as simple as sensors alone :-\
leaky exhaust, condition of valves + stem seals, injectors , lamnbda sensors , pistons rings all effect in combination.. ecu is the simplest to try..
I take your point, but the issue is mainly rough "starting", not running, once it's got started it smoothes out, and seems normal to me. Wouldn't all those things be noticeable all the time, not just at startup?
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and as for the rough running, I have seen lots of omegas lke that.. unfortunately their problems were not as simple as sensors alone :-\
leaky exhaust, condition of valves + stem seals, injectors , lamnbda sensors , pistons rings all effect in combination.. ecu is the simplest to try..
I take your point, but the issue is mainly rough "starting", not running, once it's got started it smoothes out, and seems normal to me. Wouldn't all those things be noticeable all the time, not just at startup?
after engine warms up , clearences become smaller so you wont feel it.. however, imo so many parts can cause rough starting so you still need to control a long checklist :-\
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and as for the rough running, I have seen lots of omegas lke that.. unfortunately their problems were not as simple as sensors alone :-\
leaky exhaust, condition of valves + stem seals, injectors , lambda sensors , pistons rings all effect in combination.. ecu is the simplest to try..
What's the mileage, Frank? I appreciate all the above can affect the running, but I have cars that have covered 200,000 plus miles still showing no sings of worn rings, valves, etc. They seem to last forever on modern cars. Not lambda sensors I grant.
My 2.2 is low (80,000) mileage and runs perfectly once warm and most of the time when cold.
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Hi again Frank, sorry you're still having problems :(
Harking back to my input on your previous thread, I took it as read that you'd physically checked your rubber plug covers for splits/ bits missing ??? and given the coil pack a close going over with your Mk.1 eyeball for minute cracks in the body (looks like 'marbling') :-\
Both the above, if present cause a loss of spark power to the plug electrode, hence poor starting/idling, so if not already checked then worth doing now perhaps :y.
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and as for the rough running, I have seen lots of omegas lke that.. unfortunately their problems were not as simple as sensors alone :-\
leaky exhaust, condition of valves + stem seals, injectors , lamnbda sensors , pistons rings all effect in combination.. ecu is the simplest to try..
I take your point, but the issue is mainly rough "starting", not running, once it's got started it smoothes out, and seems normal to me. Wouldn't all those things be noticeable all the time, not just at startup?
after engine warms up , clearences become smaller so you wont feel it.. however, imo so many parts can cause rough starting so you still need to control a long checklist :-\
cem: Makes sense. The only thing on your list that I could contemplate is the lamba sensor, but I've put it off because i wouldn't know how to deal with stripped threads on the downpipe, plus the £165 cost, the other things are beyond me and probably my wallet.
[/quote]What's the mileage, Frank? I appreciate all the above can affect the running, but I have cars that have covered 200,000 plus miles still showing no sings of worn rings, valves, etc. They seem to last forever on modern cars. Not lambda sensors I grant.
My 2.2 is low (80,000) mileage and runs perfectly once warm and most of the time when cold.
[/quote] terry: Mine has 89000 miles, lots of oil changes and looking after breathers. It has to endure mostly short journeys, and occasional blasts down to London and back, which is probably not great for it.
Hi again Frank, sorry you're still having problems :(
Harking back to my input on your previous thread, I took it as read that you'd physically checked your rubber plug covers for splits/ bits missing ??? and given the coil pack a close going over with your Mk.1 eyeball for minute cracks in the body (looks like 'marbling') :-\
Both the above, if present cause a loss of spark power to the plug electrode, hence poor starting/idling, so if not already checked then worth doing now perhaps :y.
PhilRich: It all looked good to me, but now I know what to look for, I'll grab my reading glasses and make a better inspection - back in a bit...
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Hi again Frank, sorry you're still having problems :(
Harking back to my input on your previous thread, I took it as read that you'd physically checked your rubber plug covers for splits/ bits missing ??? and given the coil pack a close going over with your Mk.1 eyeball for minute cracks in the body (looks like 'marbling') :-\
Both the above, if present cause a loss of spark power to the plug electrode, hence poor starting/idling, so if not already checked then worth doing now perhaps :y.
Really, it all looks like new. Earlier today I also checked the plugs themselves, in case there was some fouling, but they look dry and good, and they're GM, I put in a year ago.
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Have you had the Exhaust Manifold heat shield off to check your manifold for cracking? The 2.2 is notorious for this with the manifold cracking dead centre between pots 2 & 3 :(
If the crack is large enough that would cause issues with lambda metering and fuel trims :-\
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Have you had the Exhaust Manifold heat shield off to check your manifold for cracking? The 2.2 is notorious for this with the manifold cracking dead centre between pots 2 & 3 :(
If the crack is large enough that would cause issues with lambda metering and fuel trims :-\
Really not sure what causes this, FatherT's one has cracked I think, hear it on start up, but soon goes once warmed up slightly. Think it went around 120k or so.
No sign of it on my 165k 2.2 :-\
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Have you had the Exhaust Manifold heat shield off to check your manifold for cracking? The 2.2 is notorious for this with the manifold cracking dead centre between pots 2 & 3 :(
If the crack is large enough that would cause issues with lambda metering and fuel trims :-\
Really not sure what causes this, FatherT's one has cracked I think, hear it on start up, but soon goes once warmed up slightly. Think it went around 120k or so.
No sign of it on my 165k 2.2 :-\
I'll have a close look in the morning - I know about this, had a cracked manifold on a 2.0, but I thought it was more a problem for 2.0 than 2.2. I remember the distinctive fast tapping sound it made, then a growling sound as it got bigger, haven't heard that this time, but definitely worth looking. What about tiny leaks in the exhaust pipes, how do you find them besides the sound, and would that have a bearing on the starting up? Everything except the downpipe is replacement, it never sounded as nice as what came with the car, but it doesn't sound like holes to me.
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Have you had the Exhaust Manifold heat shield off to check your manifold for cracking? The 2.2 is notorious for this with the manifold cracking dead centre between pots 2 & 3 :(
If the crack is large enough that would cause issues with lambda metering and fuel trims :-\
Really not sure what causes this, FatherT's one has cracked I think, hear it on start up, but soon goes once warmed up slightly. Think it went around 120k or so.
No sign of it on my 165k 2.2 :-\
What causes the cracking is the cycling hot/cold in a cast iron manifold. I have had it on several 2.0 Omegas. I had one welded up, but the welder said he would not guarantee it, it would go again eventually. However it did not affect the running or starting. I have one gone on a 2.5 too. I do not think a cracked manifold would cause this threads problems.
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Terry: that's useful evidence. I had a local blacksmith weld up my 2.0 - he said it might be caused (in addition to what you said) by impurities in the casting, said it was rubbish material for the purpose, but couldn't be beaten for cheapness (affordability). Phil has a valid point about leaks affecting the lambda behaviour; how this is involved at startup I don't understand, I thought the lambdas had to get very hot before they kicked in.
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Terry: that's useful evidence. I had a local blacksmith weld up my 2.0 - he said it might be caused (in addition to what you said) by impurities in the casting, said it was rubbish material for the purpose, but couldn't be beaten for cheapness (affordability). Phil has a valid point about leaks affecting the lambda behaviour; how this is involved at startup I don't understand, I thought the lambdas had to get very hot before they kicked in.
The 2.2 has 2 lambda sensors, whereas the 2.0 had one. I have read that the upper one only controls emissions when the engine is cold, and has no effect when engine is hot. I had EML light on, took my 2.2 to a Tech2, and it read 'no. 1 O2 sensor no signal' so I changed it Now EML stays out, fault occurs less often - in three days it did not happen.
I still am unconvinced that a small exhaust leak at the manifold will affect the exhaust gas mixture - the gas is leaking out, not in.
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Terry: that's useful evidence. I had a local blacksmith weld up my 2.0 - he said it might be caused (in addition to what you said) by impurities in the casting, said it was rubbish material for the purpose, but couldn't be beaten for cheapness (affordability). Phil has a valid point about leaks affecting the lambda behaviour; how this is involved at startup I don't understand, I thought the lambdas had to get very hot before they kicked in.
The 2.2 has 2 lambda sensors, whereas the 2.0 had one. I have read that the upper one only controls emissions when the engine is cold, and has no effect when engine is hot. I had EML light on, took my 2.2 to a Tech2, and it read 'no. 1 O2 sensor no signal' so I changed it Now EML stays out, fault occurs less often - in three days it did not happen.
I still am unconvinced that a small exhaust leak at the manifold will affect the exhaust gas mixture - the gas is leaking out, not in.
I checked the manifold carefully, even underneath with a mirror, and can't see any cracks. About the O2 sensor (on downpipe): are you saying you changed it but still have the rough starting issue, albeit not as bad as mine, and still get the EML, just less often?
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Terry: that's useful evidence. I had a local blacksmith weld up my 2.0 - he said it might be caused (in addition to what you said) by impurities in the casting, said it was rubbish material for the purpose, but couldn't be beaten for cheapness (affordability). Phil has a valid point about leaks affecting the lambda behaviour; how this is involved at startup I don't understand, I thought the lambdas had to get very hot before they kicked in.
The 2.2 has 2 lambda sensors, whereas the 2.0 had one. I have read that the upper one only controls emissions when the engine is cold, and has no effect when engine is hot. I had EML light on, took my 2.2 to a Tech2, and it read 'no. 1 O2 sensor no signal' so I changed it Now EML stays out, fault occurs less often - in three days it did not happen.
I still am unconvinced that a small exhaust leak at the manifold will affect the exhaust gas mixture - the gas is leaking out, not in.
I checked the manifold carefully, even underneath with a mirror, and can't see any cracks. About the O2 sensor (on downpipe): are you saying you changed it but still have the rough starting issue, albeit not as bad as mine, and still get the EML, just less often?
This car Y188NFA is my son's car. After passing MOT I changed the cam sensor, but EML came back on and he still complained of rough starting. I took it to a Tech2, which said 'No. 1 O2 sensor no signal' I changed No. 1 (upper) lambda sensor 18 July, no EML light on, I gave car back to son saying all well. 22 July he complained of bad starting. We swopped cars for three days, it seemed fine to me. We swopped back Thursday 25 July. He has not complained since. EML is still off.
Sorry to be vague, but the car seemed fine to me. I cannot ask the forum for help unless I can describe symptons. The car is fine once warm, and has had no EML light on for ten days.
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Have you had the Exhaust Manifold heat shield off to check your manifold for cracking? The 2.2 is notorious for this with the manifold cracking dead centre between pots 2 & 3 :(
If the crack is large enough that would cause issues with lambda metering and fuel trims :-\
Really not sure what causes this, FatherT's one has cracked I think, hear it on start up, but soon goes once warmed up slightly. Think it went around 120k or so.
No sign of it on my 165k 2.2 :-\
What causes the cracking is the cycling hot/cold in a cast iron manifold. I have had it on several 2.0 Omegas. I had one welded up, but the welder said he would not guarantee it, it would go again eventually. However it did not affect the running or starting. I have one gone on a 2.5 too. I do not think a cracked manifold would cause this threads problems.
But why some more than others? FatherT's only tends to get long journey use, hardly ever used for short runs. (so quick hot cold)
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Terry: that's useful evidence. I had a local blacksmith weld up my 2.0 - he said it might be caused (in addition to what you said) by impurities in the casting, said it was rubbish material for the purpose, but couldn't be beaten for cheapness (affordability). Phil has a valid point about leaks affecting the lambda behaviour; how this is involved at startup I don't understand, I thought the lambdas had to get very hot before they kicked in.
The 2.2 has 2 lambda sensors, whereas the 2.0 had one. I have read that the upper one only controls emissions when the engine is cold, and has no effect when engine is hot. I had EML light on, took my 2.2 to a Tech2, and it read 'no. 1 O2 sensor no signal' so I changed it Now EML stays out, fault occurs less often - in three days it did not happen.
I still am unconvinced that a small exhaust leak at the manifold will affect the exhaust gas mixture - the gas is leaking out, not in.
I checked the manifold carefully, even underneath with a mirror, and can't see any cracks. About the O2 sensor (on downpipe): are you saying you changed it but still have the rough starting issue, albeit not as bad as mine, and still get the EML, just less often?
This car Y188NFA is my son's car. After passing MOT I changed the cam sensor, but EML came back on and he still complained of rough starting. I took it to a Tech2, which said 'No. 1 O2 sensor no signal' I changed No. 1 (upper) lambda sensor 18 July, no EML light on, I gave car back to son saying all well. 22 July he complained of bad starting. We swopped cars for three days, it seemed fine to me. We swopped back Thursday 25 July. He has not complained since. EML is still off.
Sorry to be vague, but the car seemed fine to me. I cannot ask the forum for help unless I can describe symptons. The car is fine once warm, and has had no EML light on for ten days.
Thanks for the clarification, it's anything but vague. It indicates the lambda may indeed be connected to rough starting, but I suppose time will tell.
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Have you had the Exhaust Manifold heat shield off to check your manifold for cracking? The 2.2 is notorious for this with the manifold cracking dead centre between pots 2 & 3 :(
If the crack is large enough that would cause issues with lambda metering and fuel trims :-\
Really not sure what causes this, FatherT's one has cracked I think, hear it on start up, but soon goes once warmed up slightly. Think it went around 120k or so.
No sign of it on my 165k 2.2 :-\
What causes the cracking is the cycling hot/cold in a cast iron manifold. I have had it on several 2.0 Omegas. I had one welded up, but the welder said he would not guarantee it, it would go again eventually. However it did not affect the running or starting. I have one gone on a 2.5 too. I do not think a cracked manifold would cause this threads problems.
But why some more than others? FatherT's only tends to get long journey use, hardly ever used for short runs. (so quick hot cold)
No idea, seems like chance. My 2.5 V6 , 150K miles,has RH manifold cracked, been so for 2 years, LH not cracked. My 3.2, 180K miles, no cracks yet.
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if manifold cracked--so what----just weld it up :y :y
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if manifold cracked--so what----just weld it up :y :y
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I had my old 2.2 saloon ( I gave it to my son) manifold welded by a coded welder who commented that the casting was like cinder toffee! When he'd done the job he said he couldn't guarantee it and it cracked on first warm up! :(
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Tim, have you tried with MAF disconnected on initial start up
Rob, you are onto something here - I've now tested this twice in the morning, when it's completely cold, and with MAF disconnected it started normally, then reconnect the MAF (without warming up at all) and it starts normally, until it gets cold again, then with MAF connected it's back to the poor startup. I couldn't believe it the first time, thought it must be a fluke, so I didn't say anything right away. What does this mean?
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Something else I tried based on a TheBoy comment: http://oldsite.omegaowners.com/forum/YaBB.pl?num=1209489601/7#7 (http://oldsite.omegaowners.com/forum/YaBB.pl?num=1209489601/7#7)
With engine cold, MAF connected as normal, foot to the floor crank for 5 seconds to clear the injectors, then start. Result: better than usual - lumpy for a while, but not scary rough like it usually is. I'll try that again later to confirm.
This would point to leaky injectors, with too much petrol accumulating when the car sits for a long time. I think the P0170 Lean Exhaust code that comes up sometimes, but is usually "Not present" when I check it, might be reinforcing this idea - as a load of noncombusted fuel blows out after starting. But I'm also a bit confused at this point, what with O2 sensor, MAF sensor, injectors and how they are interacting.
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You really need to look at the stored fuel trims using a tech 2.
If you get something putting the lambda sensor readings out constantly, such as a manifold leak upstream, the fuel trims will gradually take the mixture out until you have problems starting (lambda sensor is not used at startup, but the fuel trim is still applied).
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You really need to look at the stored fuel trims using a tech 2.
If you get something putting the lambda sensor readings out constantly, such as a manifold leak upstream, the fuel trims will gradually take the mixture out until you have problems starting (lambda sensor is not used at startup, but the fuel trim is still applied).
I PM'd the nearest tech2 (Marks...) on Sunday, haven't heard yet - is he on holiday perhaps?
Meanwhile, with the caveat that you can't be expected to form conclusions without the stored fuel trim data, follow me as I limp along here: you think this is caused by a manifold leak? How can I check that - I found no cracks, so that leaves the gasket? The other tests I've done are showing too much petrol at startup, right? You are saying this is caused by fuel trim settings applied - by the ecu, based on lambda sensor readings, which set the fuel trims - am I anywhere near getting this?
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You really need to look at the stored fuel trims using a tech 2.
If you get something putting the lambda sensor readings out constantly, such as a manifold leak upstream, the fuel trims will gradually take the mixture out until you have problems starting (lambda sensor is not used at startup, but the fuel trim is still applied).
By manifold upstream do you mean inlet or exhaust manifold?
Opening the throttle wide on start up used to be standard practice for a flooded engine in the old carburettor days, and worked on my Senator. But on a 2.2 with an electronic throttle linkage I wonder if it has any effect.
My son walked in this morning, I asked him how often his 2.2 misbehaves after my changing the upper lambda sensor. He said nine times out of ten I reminded him that when I had it for three days it never did it. He then replied brightly that this morning it ran perfectly first time, and he put this down to his filling the tank last night. So little help there.
I asked him to describe the fault. He said it starts, does not stall, but does not give enough power to go anywhere for half a minute, then it is fine.
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I know I'm a bit late coming in here. But I have the same prob and I know what it is with my car. I have a very slight exhaust leak where the front pipe is bolted to the manifold. After a mile or so the engine starts fine and drives fine. I leave it overnight and it all starts again. must get the leak done I suppose it can only get worse.
Just thought i'd mention it. Might help.
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i'm finding this topic very interesting, as my 2.2 z22xe also has a split manifold, I also have been told that they are not good to weld !. I also have a very slightly rough start which clears when the engine has run around two min's and also the manifold has warmed and the crack has closed up sufficiently. I also have the lean exhaust code which is also not present when checked.
reading what has been written before I don't have the extremely rough starting but it appears that most of the other symptoms are much the same. it may be that the manifold split is causing the lamda sensor to misbehave on both/all other cars, I had initially put my problem down to loose wire, but i'm not so sure now. what I do know is that exhaust manifolds for the z22xe are a bit like rocking horse excrement !!
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i'm finding this topic very interesting, as my 2.2 z22xe also has a split manifold, I also have been told that they are not good to weld !. I also have a very slightly rough start which clears when the engine has run around two min's and also the manifold has warmed and the crack has closed up sufficiently. I also have the lean exhaust code which is also not present when checked.
reading what has been written before I don't have the extremely rough starting but it appears that most of the other symptoms are much the same. it may be that the manifold split is causing the lamda sensor to misbehave on both/all other cars, I had initially put my problem down to loose wire, but i'm not so sure now. what I do know is that exhaust manifolds for the z22xe are a bit like rocking horse excrement !!
Depends if you`re prepared to buy new
http://www.vauxcentre.co.uk/exhaust/omega-b-1994-2003-22-exhaust-manifold-24420438-485442-79603-.php
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don't have the money rob, besides its not causing too may problems at the minute. anyway the rad you very kindly sent nup is working perfectly, many thanks again, Charlie.