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Frequent flyer Bronze
Posts: 43
 
Location: NSW | Terry: you have PM.
You may be right about the rich tune, because before I got the car back, the average fuel consumption (I have not resetted it since I got the car 3 months ago, but it may have resetted itself when the battery was changed, and maybe when the LPG specialist was working on it) went down to as low as 13.9L/100km (100% urban and not many prolonged motorway runs). But as soon as I got it back from the LPG specialist almost two weeks ago, it has been sitting on 14.1L/100km ever since...
Question: whilst bringing the car over to you, should I switch it to petrol only? I am worried that the gas situation might disappear if I switch it back to gas when I see you...or at the very least, take a while to redevelop...
Does running the engine rich for prolonged periods, cause any (short term or long term) damage?
Sorry I am such a noob!  |
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Frequent flyer Gold
Posts: 108
Location: NEWPORT QLD | Would like to know if the problem is still there on petrol - Leave it on gas and we will interrogate codes and grab sensor behaviour before doing a battery off reset to try a few days on petrol as suggested by John Rich running not usually a big problem - just like leaving an old fashioned choke out too long - lean is an issue as burns valves and melts pistons I don't think the trip computer numbers are significantly different - will also depend on this weeks butane/propane proportions in LPG etc etc and if the LPG ECU is set differently as trip computer is from petrol ECU In the end it is tank to tank manual calculations the have real meaning |
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Frequent flyer Gold
Posts: 108
Location: NEWPORT QLD | Had a quick plug in to Jeff's car tonite
1 Sensor Graphs
It is abundantly clear that the bank one (firewall sensors) are not working correctly – a simple comparison with the front back is obvious that they are staying completely lean
2 Error codes
Reinforced by the error codes stored in his ECU and causing the CEL to remain on
The lean indications of the blue line – precat sensor in bank 1 are causing the ECU to inject excess fuel, thus resulting in over rich running on cyl 1,3,5 and the miss fires reported and felt
Bank 2 is also a little over rich, but I expect that is a overflow problem in the inlet manifold from bank 1 over compensation
Hope it helps with your dealer dealings 
 (Jeff_380LX_bad sensor.jpg)
 (Jeff_fault code.jpg)
Attachments
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 Jeff_380LX_bad sensor.jpg (812KB - 511 downloads)
Jeff_fault code.jpg (212KB - 486 downloads)
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Frequent flyer Bronze
Posts: 43
Location: NSW | Deeply appreciate your help tonight, Terry! Sorry we could not say goodbye to Ann, but we hope you will find the card useful at Coles Express!
After unplugging the bad sensor, the drive home was indeed much better...almost exactly the way the car should behave. At least, the way I would imagine it to be!
Curiously, the varying revs when keeping it in fourth gear, and using the brakes to keep the speed going downhill between an indicated 60-62km/h, has returned. But perhaps this will disappear once the faulty sensors on bank one are replaced?
In any case, I am forwarding your findings to the dealer, to see what he says. Hopefully I won't have to drive 600km this weekend!
Kind regards,
Jeff |
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Frequent flyer Bronze
Posts: 43
Location: NSW | Good morning all, especially to Terry and John! So the ACT dealer responded and advised me to get a quote, and to ask the LPG specialist for a retune afterwards. Just spoke to the service advisor that Terry recommended, and he is convinced that, instead of two faulty oxygen sensors, I may have one faulty oxygen sensor (I think he is referring to the pre-cat one on the firewall side...the blue line in the middle graph), and one catalytic converter...? (This is despite me advising him that the post-cat green line in the middle graph does respond with more throttle input, as with the pre-cat blue line but that is moving less than ideal, and the bottom graph is exactly how Terry's daughter's Outlander behaves...he is saying that, perhaps at least in the 380, the green line should not move much at all...?) [Perhaps Terry will need to Reply All to this service advisor in our emails so far, with the part of the graph where we were using petrol, and where I was pumping the accelerator pedal whilst on LPG. This may prove that the post-cat green lines ARE supposed to move up and down also, just in a lower frequency than the pre-cat sensors...?] So now to have it diagnosed by the service advisor and his team, would cost $145. I am not sure if the ACT dealer likes the sound of this, but I will have to let him know regardless. In any case, I have a feeling I will have to cop this charge myself for now, just to get the ball rolling... At least things are heading in the right direction I guess! |
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Frequent flyer Gold
Posts: 1092
 
Location: An island off southern Tasmania. | No you don't have to cop the charge.
Tell him to use a mobile mechanic service at your place? |
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Frequent flyer Bronze
Posts: 43
Location: NSW | I can certainly try to do that. But I wonder if a mobile mechanic will be more capable of pinpointing the exact causes of all the issues, than a Mitsubishi service centre?
I will just put it to the dealer and see what he says.
Just looked at some of your "resurrection" threads, John. I am beginning to wonder if it is better to pay YOU to fix the whole thing for me! I say this because, if the sensor in Bank 1 has in fact been faulty for some time, how long has the engine been running lean on that side (and correspondingly, rich on Bank 2)? If that is the case, then I might be better off swapping for a second hand undamaged engine instead! |
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Frequent flyer Gold
Posts: 108
Location: NEWPORT QLD | I believe the Outlander plot a few post back is correct - veh has only 7700 km
Also have a look at
http://www.lotustalk.com/forums/f101/2007-exige-s-throwing-p0420-p0171-60410/
post 13
Similar post for a Lotus, with comment that if post cat sensor is cycling more than 6 times for every 10 or the precat then cat is getting tired and 10 to 10 means cat not working at all
Can't re-find the earlier article I read which said the cat absorbs oxygen during lean time of the pre cat controller to then use to burn off pollutants etc over following cycles
Seems this is a good explanation of why we see some rich lean activity post cat depending on how much we over rich during acceleration
Copying the full graph to John at dealer may convince him that ur post cat sensor is still working - as we did get some rich blips on it |
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Frequent flyer Gold
Posts: 1092
Location: An island off southern Tasmania. | you shouldn't need to pay for anything...that's what a warranty is for.
no need to replace the engine matey...nothing wrong with it. |
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Frequent flyer Bronze
Posts: 43
Location: NSW | Thank you very much Terry for sending the complete graph to John (the service advisor), and explaining how the sensors are behaving under the different conditions we have presented (running on LPG, running on petrol, and pumping the accelerator whilst running on LPG). Please send the screenshots as a separate attachment as you did before, rather than in line with the email text as I did...because he was then unable to zoom in to view in more detail...silly me! 
John (the Administrator): the car was purchased early in June, so by now it is just out of the standard 3-month warranty. But because it stalled in a motorway tunnel on day one (and again in a car park, plus a milder symptom of the delayed then surged acceleration, which means the engine may already have been running lean at the time, if not before! More about this later...), and since the first repair, it has started misfiring (still within the warranty), the dealer is obliged to fix it. But it does not stop the dealer from going for a short term fix, which is why I am requesting the work be done properly in a Mitsubishi service centre that has experience dealing with dual fuel 380s. Let's see what the dealer says this time... Regarding the engine, I am just concerned that the prolonged lean running (at least on Bank 1 based on the graphs) would have already caused enough damage that cannot be seen/detected unless the engine is pulled apart. As you've said, these oxygen sensors are not supposed to last beyond 100,000km, and the car has now done in excess of 147,000km, so it may have been running lean for almost 50,000km, if not more. Curiously, none of this was picked up by the pre-purchase inspection report I've purchased prior to purchasing the vehicle. Tried asking the inspecting company about their 30-day warranty (http://www.vehicleinspectors.com.au/Conditions/) immediately after the motorway stall and what they can do about this, and asked again recently, but no joy from them either... Hopefully the dealer will just approve a once-and-for-all fix at Terry's recommended repairer, and it will work out fine. But yes, I am still concerned about the prolonged lean running, and how much damage it may already have caused the engine. A replacement engine from eBay and/or the wreckers? Hmm...
It was SO much easier when I bought a (then) 4-year-old and supposedly unreliable Astra Turbo with 104,000km and a full exhaust from the dump pipe onwards, back in 2007, and that was with a mere NRMA inspection report. That car has now done almost 175,000km, and besides regular servicing, wear and tear and despite more mild modifications, still running great with no sign of needing a new clutch yet (indeed, the friction point is pretty much still at the same amount of clutch pedal travel, and it still clamps fine)! And now so much more trouble with this particular 380 with supposedly a far more detailed inspection report...? Quite sad and incredible, really! *sigh* Really hope the 380 is fixed properly so I can keep it, though, as it definitely has a far broader range of talents/capabilities than my more narrowly-focused modified Astra! |
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Recent LPG Starvation Issue
