|
|
Frequent flyer Bronze
Posts: 43
 
Location: NSW | Sadly it is not over...
Cold started the vehicle after dinner (not below the "C" mark cold, but right at the "C" mark). After it warmed up auto-switch to LPG, noticed a mild trembling at idle again - but nowhere near as bad as before. Drove OK to uni.
Cold-ish started the vehicle again just before 10p.m. to head home. While still running on petrol (I think...can't remember if it switched over to LPG by then) and drove slowly within uni grounds and had to come to a stop, the engine died while I was in Drive. Pushed it back to Park, brakes on then started the engine again and drove out of uni. Noticed the delayed and sudden revving up again when asked to accelerate from 20km/h or so at small throttle openings (e.g. after turning into an intersection). Barely made a few blocks out of uni (definitely on LPG by then) when the CEL came back on. Trembling at idle was getting worse then, but bearable. By the time I passed the Moore Park Road intersection and stopped at a red light, the trembling at idle became such violent jerking at random intervals yet again that I knew the problem is back, and I had to promptly switch back to petrol. Managed to drive home ok, but noticed after parking and with the engine running, that the exhaust note is not as even and consistent as it normally should - though nowhere near as bad as LPG. CEL is still on by the time I switched off the engine.
Already booked the car with Sydney City Mitsubishi this coming Friday morning for the headlight switch. Looks like I will have to call them this Monday so they can deal with this also...
Just a little bit baffled by what is/are causing this. My wallet is not liking me again...sigh.
One good thing out of this, though: on a downhill slope, whilst in Sports Mode and keeping it at around an indicated 62km/h in 4th gear by the appropriate brake pedal pressure and with no accelerator, I noticed that the engine revs no longer fluctuate between about 1100rpm to about 1400rpm - something it has always done since I've bought the vehicle. So here is hoping Terry's fix is still in the ECU somewhere!
Maybe it is time for me to hit the wreckers and try to find some headers...although there is no knowing how much longer those ones will last! |
|
| |
|
Frequent flyer Bronze
Posts: 43
Location: NSW | A quick update...
Took it for a short trip across an adjacent suburb today, now running exclusively on petrol.
It has now become apparent that at the same throttle openings as before, the engine revs is picking up far less up inclines, resulting in far less acceleration until the throttle is pushed much deeper. Seems to drink way more petrol in the process as well. On the other hand, on the same downhill slope, the car now rolls up to barely over 40km/h with no accelerator instead of 50km/h or more before. CEL is now staying on.
Oxygen sensors?
Edited by dazeet 6/9/2014 23:28
|
|
| |
|
Frequent flyer Gold
Posts: 108
Location: NEWPORT QLD | Maybe loose connection to oxy sensors exacerbated by stiff wiring etc when engine cold causing intermittent fault
Try unplug and re-plug all the plugs etc on front and rear primary sensors ?? |
|
| |
|
Frequent flyer Bronze
Posts: 43
Location: NSW | Drove it from the other side of Sydney to uni and back yesterday. The CEL turned off after a while, and acceleration subsequently seemed to have improved.
So the cycle basically goes like this:
Switch it to LPG --> drivetrain behaviour appear to worsen with increase in coolant temp (from the auto-switchover point to normal operating temp) --> CEL turns on and behaviour is bad enough to have to switch back to petrol --> behaviour improves but still poorer than average acceleration especially at low revs --> CEL turns off (perhaps after a bit of harder acceleration) but symptoms still present especially when idling --> the cycle repeats if I switch it back to LPG...
Will try to unplug and re-plug whichever oxygen sensors that I can (but not really sure if this will help though, given the above cycle). They are the screw-on screw-off type aren't they?
Vehicle has done more than 157,000km - more than 100,000km since the LPG system was installed. Most of this would've probably involved cruising in Canberra - consistently high exhaust gas temperatures I think...
Edited by dazeet 9/9/2014 14:07
|
|
| |
|
Frequent flyer Gold
Posts: 1092
 
Location: An island off southern Tasmania. | hey mate...it may not be an oxygen sensor.
you need to get the code read from the OBD port....
to screw the oxygen sensors off you REALLY should use an O2 removal socket...only about 10 bucks from sup[a cheap auto...has a cutout for the cable.
I personally stuffed a few before I learned my lesson....get the tool!
I have never heard of an o2 sensor showing the signs of acceleration that you describe...get the codes first, leave the O2 sensors alone till you do is my advice.
I reckon look at the mass airflow sensor...or a vacuum leak on a hose somewhere |
|
| |
|
Frequent flyer Bronze
Posts: 43
Location: NSW | With the people at Seven Hills now. They are trying to work it out. I have already told them about the MAF sensors and vacuum leak etc.
Have also called John from Sydney City Mitsubishi while I am waiting (because I was really wondering if aging O2 sensors would have melted one of the precats prematurely in the first place - the car by now has done over 158,000km). Terry: John mentioned how you took your car to Vic to have the perfect tune? Is it from John (our super admin)?
Really tempted to just drive the car over to Vic also. Just want to fix it once and for all rather than having (LPG-related) issues every few thousand km. Besides, my wife and I are overdue for a short break! |
|
| |
|
Frequent flyer Gold
Posts: 108
Location: NEWPORT QLD | I didn't take mine to Victoria
I bought the cable and got the software and then did about 15 iterations of adjustment to get the petrol ECU long term fuel trim as close to zero as possible when we went Brisbane and back last Xmas.
I did that because my initial long term fuel trim was about -15%
Remember the petrol ECU sees the O2 sensor readings and sends (petrol) injector timings which are recalculated by the LPG ECU to inject he correct amount of gas, so If the gas is set wrongly the long term fuel trim will try to correct it. My problem was then getting CEL for lean idle when the system overcompensated on trailing throttle.
That was the adjusted map I loaded into yours a couple of weeks ago, and it appeared to be running OK when we went for the 10k or so test run
|
|
| |
|
Frequent flyer Bronze
Posts: 43
Location: NSW | Thank you Terry for clarifying.
Sorry forgot to upate - on 16/9/2014 the Seven Hills people gave the system a tune, said "no charge" and told me to drive it again and see how it goes.
I asked how often should I run the car on petrol only. They say about 30-45 minutes each week.
Have been doing so for most Sundays since, and it seems so far so good again 
Wish I can pinpoint what exactly is/are causing the issue. But if it is doing OK, then I am happy! |
|
| |
|
Frequent flyer Bronze
Posts: 43
Location: NSW | Update.
It was the aging spark plug seals. Engine oil was leaking out through them, thus affecting spark plug performance and hence triggering the misfire/lean error codes etc.
No more warning light since the seals were replaced. Bit more low rev torque as well  |
|
| |
|
Frequent flyer Gold
Posts: 1092
Location: An island off southern Tasmania. | Glad you hve it sorted...LOL...took 3 years though. |
|
| |
Recent LPG Starvation Issue
