How Does The Ecu Learn On A Non Turbo?reset The Ecu?

[samuri]

How does the ECU learn?

Is it through time spent at different speeds, average speeds, and rates of acceleration or what? Is it always adjusting and if so why would a reset be necessary?

I had the ECU checked out by nissan at the 85000km mark and no adjustements were required.

My LPG Emer sequential vapour injection system was recently professionally installed.

These systems piggyback off the ECU I believe and learn how to operate on LPG based on the ECU.

I am thinking of resetting the ECU as I believe my LPG system should be getting better mileage. However as I am in a remote area I am concerned I may somehow stuff up the motor with no assistance within a few hours drive. Currently 6km / litre on LPG everything else seems fine, easy to start ,good acceleration high speed overtaking no problem.

Before the conversion I was getting around 7.4km to 9.1km a litre on petrol depending on speed and driving style. I should be getting only 10 % to 15% worse but I have been told it could be as little as 5 %.

Straight after conversion I drove 2500km on the highway in 2 days. I can’t return to the installer until january next year.

Vehicle - 1996 non turbo automatic skyline GTS

Any thoughts as to poor LPG fuel consumption immediately after conversion.

i havent run on petrol since conversion as it is a $1-60 a litre on average

here, apart from the automatic start up. ouch

[iseekool]

LPG in general is not as efficient as petrol. LPG has less energy, therefore you use more. Your consumption of LPG seems about right. I'd check your air filter first

Only way to increase LPGs efficiency is to up the engine compression or up the boost slightly - this will give you more torque - there increasing engine efficiency.

ECU reset will not do much IMHO. Resetting will not do any harm.

[samuri]

LPG in general is not as efficient as petrol. LPG has less energy, therefore you use more. Your consumption of LPG seems about right. I'd check your air filter first

Only way to increase LPGs efficiency is to up the engine compression or up the boost slightly - this will give you more torque - there increasing engine efficiency.

ECU reset will not do much IMHO. Resetting will not do any harm.

Thanks.

I am aware that consumption wont be the same as mentioed in my post.

At a pessimistic 20% less on a figure of 9.1km/litre should have me at 7.3km/litre not at 6km.

I checked the air filter just before I drove the 2500km. I took accurate figures on the route so my return driving condtions were almost identical when I compared the LPG and petrol systems.

How long does it take the ECU to learn?

Edited October 16, 2010 by samuri

[Sarumatix]

Herm you say you are in a remote area? The simplest thing would be to take it to a dyno and see what you get there.

[djvoodoo]

U gotta remember that the standard ECU Map or "data" is stored in ROM, meaning it's burned into the chip on the ECU. The data therefore cannot be changed unless the chip is remapped/reburned.

Resetting the ECU won't do much, it won't "learn". All it will do is re-evaluate what's in the ROM and continue to do what it is programmed to do.

[iseekool]

Thanks.

I am aware that consumption wont be the same as mentioed in my post.

At a pessimistic 20% less on a figure of 9.1km/litre should have me at 7.3km/litre not at 6km.

I checked the air filter just before I drove the 2500km. I took accurate figures on the route so my return driving condtions were almost identical when I compared the LPG and petrol systems.

How long does it take the ECU to learn?

I suppose there are quite a few factors ie. your engine wasn't built as a factory dedicated LPG engine (eg. new falcons, camrys and commodores) - possibly the cam profiles, compression and ignition systems have been optimised for LPG (don't quote me on this - it's just an educated guess).

Some forums and motoring jurnos out there claim you use about 25% to 30% more gas as opposed to petrol, but even at that rate, LPG is still cheaper - if you do the high milage.

[xALmoN]

doesn't the engine run hotter with LPG?

since its already a gas, it doesn't have as much of a cooling effect as vapourising petrol.

i dont know, expanding compressed gas also has a cooling effect, but i'm not sure if its more than evaporating petrol..

why did you go cng?

[mad082]

in a perfect world you might get 10 or 15% worse fuel economy on LPG, but more often than not it will be about 30% worse (which is about what you are getting), so the actual savings per L of LPG take a hell of a long time to cover the cost of the conversion if you don't do a lot of kms.

as for the ecu reset, the amount that the ecu learns is very little, and without it still using petrol it will be using very little of the small amount that it does learn. the simplest way to explain the self learn on an ecu is to say it's like a calculator. you can make it do all sorts of calculations and save stuff in the memory, but at the end of the day, even if you reset it, 1+1 will always equal 2.

[jrh001]

How does the ECU learn?

Is it through time spent at different speeds, average speeds, and rates of acceleration or what? Is it always adjusting and if so why would a reset be necessary?

I had the ECU checked out by nissan at the 85000km mark and no adjustements were required....

Hi,

On an AU Falcon, there's a procedure to follow after an ECU reset:

- When power is re-connected, start car and idle in this sequence

- 2 minutes idling with the transmission in drive and A/C on.

- 2 minutes idling with the transmission in drive and A/C off.

- 2 minutes idling with the transmission in neutral and A/C on.

- 2 minutes idling with the transmission in neutral and A/C off.

- Drive the car on the road, for at least 5 minutes under variable throttle positions.

Do Skyline's have a similar procedure?

JH

[iseekool]

Hi,

On an AU Falcon, there's a procedure to follow after an ECU reset:

- When power is re-connected, start car and idle in this sequence

- 2 minutes idling with the transmission in drive and A/C on.

- 2 minutes idling with the transmission in drive and A/C off.

- 2 minutes idling with the transmission in neutral and A/C on.

- 2 minutes idling with the transmission in neutral and A/C off.

- Drive the car on the road, for at least 5 minutes under variable throttle positions.

Do Skyline's have a similar procedure?

JH

To my knowledge on a stock Skyline - disconnect the battery and push the brake pedal for around 30 seconds. Reconnect the battery and away you go.

[iseekool]

I've been doing a little reading into this. Looks like your ECU may need more tweaking/tuning to get the best from LPG - hopefully by increasing your engine torque you will also reduce LPG consumption.

-> http://www.acl.com.au/web/acl00056.nsf/0/3...3e?OpenDocument