[zxj24]

Greetings,

I have Subby outback 2000 2.5. Now I have driven this car in Europe for over 4 years mainly on LPG. I noticed that after start in the morning when waiting on a traffic lights, the RPM will drop to less then 500 and from time to time the engine will stall. I noticed that every morning when engine is cold, after few minutes of running, I will have this symptoms on first traffic lights ever day now.

After running longer for 10 minutes when the engine gets, I guess normal operating temperature, it is fine and will not stall. The RPM will stay at normal level on traffic lights. As I mentioned I drive the car on LPG. First I observed that on LPG after the engine switches from Gas to LPG and thought it is related to LPG but to eliminate LPG from the equation I drove the car on Gas all the time and has same symptoms while driving on Gas, although I must say less frequently. But no matter on what fuel I drive, it will stall on my first traffic lights. Then it will be fine, I will manually switch to LPG and it is fine on next traffic lights.

Any idea of the issue? Perhaps some temperature sensor, some vacuum? I would appreciate your advice. Hopefully no need to change any parts/sensors as I will need to be importing from USA.

 

[zxj24]

Hi Dave,

Thanks for your advice. I have had the LPG installation done over 3 years ago by LPG authorized shop. Here in Poland LPG is very popular due to high gas prices. In general gas here costs more than double then in US and LPG is less than half of gas. These days the LPG installations are very advanced and have lot of electronics, injectors etc. I have been very pleased with this installation. Of course it requires more often service, like for instance every 10k km I need to change air flow LPG filter and every 30K km a liquid flow LPG filer, other than that very reliable and no issues. I have seen cars running over 10 years on LPG and little Fiats, VW or Renault done over 200K km on LPG alone. I have just done service a month ago as I had some symptoms running on LPG only. I changed sparkplugs, changed both filters and it was great improvements in performance as well as LPG millage. Normally I would go to my LPG specialist if it was only LPG problem but since I have these symptoms running on gas as well, it is not related to LPG alone, at least what I think so. Of course LPG is more sensitive but again after running for 10 minutes all is good.

Just this nuance know. If you want to see some photos of my LPG installation just let me know. I can take and upload some. The engine light comes and goes.. I stopped paying attention to the engine light as it will come ON when the LPG needs service. So I would have LPG serviced and then it is happy until next time. So yes I can try to read the codes and see what it says.

 

[zxj24]

Thanks yeti, I will definitely check the vacuums as it sounds like cheap to fix, any techniques to verify the vacuums?

Thanks,

 

[zxj24]

Hi Cardoc,

Thanks for your advice. I will try to read the codes, maybe even this afternoon. Actually the weather here is not cold yet. It is fall but it is nice and pleasant, This morning when I was leaving home around 8 am was 62 in F. but normally in the morning at this time of the year is around 50 in F. So not too cold yet. I did replaced the O2 sensors about 1.5 ago. I ordered them from US, universal aftermarket but never had any problems since then. The fuel quality is not that bad here, plus dont forget even the cheapest gasoline here has more octanes then the premium in US , so I think my Subby never complained about the gasoline here. I mainly drive on LPG but obviously the cars starts on gas before it switches to LPG. The symptoms are bigger on LPG probably for the fact that LPG has less octanes then gasoline. but again i drove my Subby for over 3 years now on LPG and very happy with the performance.

I need to inspect the vacuums and will check the O2 sensor. Any advice from you on a technique to identify a bad vacuum?

 

[zxj24]

Hi guys,

Thanks for looking at my post and all your advices. Problem solved. It turned out that there was no issue with leaking vacuum, no issues with any sensors, O2 and all my suspicions. Found a subaru mechanic who adjusted valves and all problems went away. The car runs like a champ, very smooth, so responsive to acceleration. I am shocked by the performance improvements, not mentioned way better mileage.

Regards,