Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: shyboy on 17 December 2012, 12:51:46

Title: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 17 December 2012, 12:51:46
Firstly, hello again to all who know me! Not been on for some time due to lack of involvement for health reasons.
Some of you may know that I bought Wingman's lovely 3.2l Y reg. Elite LPG saloon 2 years ago, which is still a great low mileage example but is giving a bit of trouble lately which is taxing my elementary knowledge to the limit.
I took it to Leyland LPG (forum members but not very active) with an LPG rough running problem and they solved a 'dirty' injectors problem, but the problem has recurred recently, at the start of a few cold snaps. I'm quite happy to go back to Leyland LPG but wonder if anyone can help me to decide whether the problem is likely to be LPG or petrol related.
The emissions light is currently on permanently and the following codes are thrown up. I think I've got them down correctly.
0130
0302
0304
0300
0302(again)
0304(again).
I think these indicate an O2 problem, and various misfire reports which seems to fit in with the symptoms.
I noticed that the switchover to LPG was happening very soon after starting from cold and certainly long before the temp. gauge was showing any reading. What started as a slight hesitation on switchover progressed to obvious misfiring for about 10/15 seconds which I put down to a too cool evaporator and then everything went well. This does get very hot, but there is a small water loss problem which requires infrequent top ups. The misfiring problem doesn't seem to be related to this however.
I then noticed the rev. counter fluctuating erratically from time to time, without any actual increase in engine revs., which has led my simple mind to thinking about crank sensor problems. This also occurred without the engine running when I was retrieving the codes using the pedal trick. I'm going to buy the appropriate crank sensor anyway but hope that the experts might be able to suggest a course of action which a decrepit creaking gate might be able to understand.
The engine will not start now, and I realise that the petrol operation needs to be spot on before going down the LPG investigation route, and any help would be much appreciated.
Many thanks,
Bill.
 
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: Kevin Wood on 17 December 2012, 14:31:59
Long time no see. :y I hope your health issues are now behind you.

Complete failure to start on petrol might well be crank sensor. Does anything happen at all when you crank the engine over? A flicker from the rev counter or flashing EML perhaps (indicates an immobiliser issue)?

Does the fuel pump in the petrol tank run for a few seconds on switching the ignition on and again when cranking (might need an assistant to listen for this)?

I'd tackle the failure to start first then drive it on petrol only for a week or so just to see if the misfire pops up on petrol.

I don't think early switchover is an issue. Mine switches over after 30 seconds at the moment (vapouriser temperature sensor broken!) and it's fine. Lumpy running at switchover is normally poor mapping of the LPG system - or perhaps a dodgy injector or LPG pressure setting has moved, etc. It's possible that your vapouriser temperature sensor has failed, I guess, but I don't believe that's the main issue.

Is the engine running at the proper temperature (just under the mid point on the gauge)?
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 17 December 2012, 17:28:47
Hi Kevin. Thanks for your interest. Health is now being maintained with the use of pills etc. so I'm able to take a proper interest in my Omegas again. I hope you're keeping well.
Firstly, the engine temperature has always been right despite a small loss of water which I suspect is a slightly leaky water pump. I don't recall any misfiring, on petrol only, until this episode.
The rev. counter was starting to be erratic when driving and this was repeated when the pedal trick was used, (without engine running of course). Would you expect to see this alongside a crank sensor problem?
The battery is on charge at the moment so I'll check tomorrow what happens when cranking if this rain stops.
On reflection, I think the fuel pump priming noise before turning the engine had possibly disappeared on the last few attempts and I'll check that out also. You may have put your finger on something there.
Leyland LPG were very helpful and obliging and I'll happily let them look at that side of things when/if I get to that stage.
Thanks again for your help.
Bill.
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: feeutfo on 17 December 2012, 17:50:52
0130 is 02 sensor bank 1 yet the missfire cylinder specific codes are all bank 2. Are the number correct?

any jubliee clips leakin? on fuel or cooling system?
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 17 December 2012, 18:40:51
I'm not clued up enough to fully understand your comment, Chrisgixer, but I'll check everything and post again tomorrow.
Thanks.
Bill.
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: JamesV6CDX on 18 December 2012, 13:31:38
I don't suppose the fuel trims have gone THAT far astray....?  :-\
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 18 December 2012, 14:29:52
Hi James. Hope you and yours are all well. I'm still looking to do the stem seals on the 2.6 estate which is SORNed at the moment but I'll PM you separately about this in the near future, if it's still something you would want to do. I will - honest!  :-[
Did the pedal trick again this morning from cold without having turned the engine since yesterday and got the following (slightly different) codes. I don't know whether these are in date/incident order but I'm sure others will.
0150
0300
0304
0300
0302
0304
0130
0130
0302
0303
Ran them through several times to be certain.
There is nothing leaking to the point where it might affect this problem, and I did hear the petrol pump priming on switching on the ignition. Also got an intermittent 'pulsing' noise, from the air inlet box area as far as I could tell, which lasted for about 5/10 seconds and repeated a couple of times at 2/3 minute intervals. Is this the MAF sensor doing its job?
Just checking through the codes list again to educate myself and will make another start attempt shortly if this so-and-so phone will stop ringing.
The rev. counter didn't repeat its erratic behaviour today by the way.
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 18 December 2012, 14:58:27
Just attempted starting from cold and the damn thing's fired up as if nothing had ever happened.
I didn't wait for switch-over in case that cocked things up again, but ran it round the block with no problems. Tickover settled back to normal 500/600rpm as it warmed up, so as Kevin suggested I'll run on petrol only for a while to see what happens. If that continues to be OK it looks like a recurrence of the LPG injector(?) problem which is outside my ability to solve so Leyland LPG will be called on  again, (and hopefully not Green Flag in the meantime).
Having said that, do the above codes suggest any other problems on the petrol side?
I suppose I'll have to have the codes removed by my pet garage owner, who seems very fair but won't touch LPG with a barge pole.
Many thanks for your help. Just going to start it again. Fingers etc. crossed.
Bill.
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: Lazydocker on 18 December 2012, 15:14:49
It could be coil packs starting to fail, only showing up on LPG :-\ :-\

My thoughts were on fuel trims too :-\
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: feeutfo on 18 December 2012, 16:17:39
Cirtainly run it on petrol for a while and see if that behaves, it would be nice to clear the codes, then if the LPG then runs ok, but then gradually starts to decline, that would indicate fuel trim issue IME and that the gas set up is off. The rate of decline might indicate the severity of the LPG problem.

If it runs ok on petrol for a while, then instantly plays up on LPG, look for missfire faults, such as plugs, coil pac, or water/oil in the plug wells.

Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: Kevin Wood on 18 December 2012, 16:27:00
IME the fuel trims won't prevent it starting. They can make it very grumpy at idle after starting if they have reached their limits, but if it's not even trying to start, my thoughts are still crank sensor, especially as the rev counter has been misbehaving. Now it's starting, though, run it around on petrol for a while (don't go too far away from a spare crank sensor!) and see how it behaves.
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: feeutfo on 18 December 2012, 16:30:52
IME the fuel trims won't prevent it starting. They can make it very grumpy at idle after starting if they have reached their limits, but if it's not even trying to start, my thoughts are still crank sensor, especially as the rev counter has been misbehaving. Now it's starting, though, run it around on petrol for a while (don't go too far away from a spare crank sensor!) and see how it behaves.
Chrisgixer goes off for a re read. :-[
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 18 December 2012, 20:12:10
Just completed a 25 mile trip with 2 stops and restarts and noticed that the emissions light had disappeared. It ran beautifully on petrol until I made a final stop at a corner store when an obvious hesitation at idle brought the light on permanently again. Then ran fine for the 1 mile to get home.
I'll check out all points mentioned, and look at the plugs again, which I replaced very carefully about 1000 miles ago, and a new crank sensor will shortly be stored on board. The coil packs looked fine when the plugs were changed.
It'll be petrol only for a few days to see what happens and then I'll try a switchover.
I presume it's normal for LPG to gradually get out of tune over time. I don't know how often it's been serviced during its lifetime.
Thanks for all your help.
 
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: henryd on 19 December 2012, 11:18:39
Just completed a 25 mile trip with 2 stops and restarts and noticed that the emissions light had disappeared. It ran beautifully on petrol until I made a final stop at a corner store when an obvious hesitation at idle brought the light on permanently again. Then ran fine for the 1 mile to get home.
I'll check out all points mentioned, and look at the plugs again, which I replaced very carefully about 1000 miles ago, and a new crank sensor will shortly be stored on board. The coil packs looked fine when the plugs were changed.
It'll be petrol only for a few days to see what happens and then I'll try a switchover.
I presume it's normal for LPG to gradually get out of tune over time. I don't know how often it's been serviced during its lifetime.
Thanks for all your help.
 

I think I would fit the new crank sensor and keep the old one on board for a spare :y
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: Lazydocker on 19 December 2012, 11:45:13
Just completed a 25 mile trip with 2 stops and restarts and noticed that the emissions light had disappeared. It ran beautifully on petrol until I made a final stop at a corner store when an obvious hesitation at idle brought the light on permanently again. Then ran fine for the 1 mile to get home.
I'll check out all points mentioned, and look at the plugs again, which I replaced very carefully about 1000 miles ago, and a new crank sensor will shortly be stored on board. The coil packs looked fine when the plugs were changed.
It'll be petrol only for a few days to see what happens and then I'll try a switchover.
I presume it's normal for LPG to gradually get out of tune over time. I don't know how often it's been serviced during its lifetime.
Thanks for all your help.
 

I think I would fit the new crank sensor and keep the old one on board for a spare :y

Knowing a little about the car, I doubt it has ever been changed so the old one won't come out easily ;)

Crank sensor is still a candidate but I still wonder if it is related to the LPG mapping being off :-\
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: shyboy on 20 December 2012, 10:56:05
Point taken, henryd.  :y
Lazydocker. Do you mean you know this particular vehicle? Wingman had all work done by a VX main dealer, with a complete documented service history, and I can't recall seeing any reference to a crank sensor. However, when I changed the plugs recently, two of those on the passenger side were only finger tight, (honestly), so I wonder whether the car's been subject to the usual VX standards of attention.
Anyway, I won't be able to do much until the holiday break, so fingers are still crossed that it keeps going 'til then. Otherwise, SWMBO's Corsa will get some extra use. :'(
Merry Christmas.
Bill.
Title: Re: Rough petrol/lpg switchover. Now won't restart.
Post by: Kevin Wood on 20 December 2012, 11:33:32
The plugs in these engines often work loose so it's not unusual to find a couple only finger tight. I'd say that doesn't reflect badly on the car's previous maintenance regime. One thing that does help is to torque the plugs up, go and have a cup of tea while the crush washers settle then go round them again and double check the torque. :y