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Discussion Starter #1
Hi Everybody,

I'm newbie on this forum. I need some help.

I recently imported an US 0'4 Murano in Europe. I installed LPG system (which is quite popular in Europe, 1 liter is double of the price of regular fuel) After while all 3 cats went bad (which is normal as the exhaust gas is completely different) so I removed the "honeycomb" and put back the shell. (the LPG is considered as ecological fuel so it can pass the emission tests)

Now let's go to my problem/question. The LPG (liquid petrol gas) system is set to read air/gas mixture ratio from Mo's ECU. But the ECU is confused because of getting wrong info from O2 sensors (no cats) and the end result is the higher fuel consumption and loss of power @ higher RPM.
The LPG system can be manually adjusted and it is possible to set preferred air/gas mixture ratio. Does anyone know what is normal ratio (when it has all cats and everything works just fine) at this type of Mo's?
NOTE: Usually the car's normal petrol and LPG ratio should be the same.

I must say I really love the car and I hope I'll enjoy it as much as possible.

Tnx a lot in advance.
 

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ensaar-

You are not alone. Another member converted his MO to run on LPG. I can not recall his name at this time but he was based in Europe and had some issues with burnt valves I believe. Hopefully another member will remember his name and then you can contact him for the particulars on the installation.

-njjoe
 

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Discussion Starter #3
tnx njjoe,

I installed the valve lubiractor so I hope I will not have problems with burnt valves. The LPG is more dry than regular unleaded petrol. My wish is to get somehow the normal gas/air ratio so I can set up the LPG processor.
 

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There are a lot of companies in the US that handle gas to LPG conversions. Might want to consult them. Also a copy of the service manual might help you. It will let you know what the expected voltages are supposed to be before and after the cats.
 

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ensaar-

I found him! I found the member who converted his MO to run on LPG. His name is adiadrian. You may want to send him a PM. He may have the specifics you are looking for.

I am also including a link to a thread he initiated that may interest you. Apparently he had issues with the engine after the conversion that he suspected had something to do with the valve clearance. Here's the thread: http://www.nissanmurano.org/forums/66-problems/9676-engine-arythmia-idle-speed-cvt-failure-2.html

-njjoe
 

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Discussion Starter #6
tnx buddy, I just sent him PM, and hopefully he'll be able to help me.

oh...and tnx again for going trough the old threads...
 

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Optimum air fuel ratio depends on what fuel you are running. For normal fuel injected gas it 14.7:1. Having no cats does not affect the AFR since the sensor used to adjust fuel trims is pre cat. The post cat sensor is only there to monitor the effectiveness/health of the cat.
 

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Optimum air fuel ratio depends on what fuel you are running. For normal fuel injected gas it 14.7:1. Having no cats does not affect the AFR since the sensor used to adjust fuel trims is pre cat. The post cat sensor is only there to monitor the effectiveness/health of the cat.
The 14.7:1 ratio you reference (called the stoichiometric mixture) is a target that is only used during low-load conditions, otherwise knocking and pinging will occur. The ratio is usually lower (richer) than 14.7:1.

-njjoe
 

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Actually the target is usually 14.7:1 since a majority of driving is at low load cruising speeds. Richer AFR's are targeted under moderate to heavy load. As far as avoiding knock it depend on the tune. You can tune out knock by running richer and slowing down flame speed or you can run stoich and run less timing. Tuning is a balancing act and most use a little of both.
 

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Hi Ensaar,

I just had my Murano converted a few days ago, I used the BRC Supermax kit with electronic flash lube - what kit did you go for?

Not sure about the gas/air ratios to be honest so sorry I cant help you out on that one.

cheers
 

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Discussion Starter #11
Hi ressull, I put the latest Zavolli system + the valve lubricator. What is your city/hwy milage on gas?
 

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Hi everyone. It is a long time since I have been to the forum. Anyway concerning the problems that I have had all has been repaired. Needed to get the whole engine refurbished. Since then everything has been running ok. Done so far 130,000KMs and the engine is running ok. Lubrication is a must have when running on LPG!
 

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After cat O2 sensors don't affect fuel delivery, the only thing they do is control condition of cats.
Perfect Air/fuel ratio is 14.7 (?)
You can check upstream O2 sensor signals by scanner, but
I don't know normal signal range for wide band O2 sensors.
Old sensor signals go up and down from .45V
Wide band sensors have 5-6 wires, old sensors have 4.
 
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