1.9 sdi skoda fabia questions

[cecilio]

Hello,guys i have just registered to ask something about my car Skoda fabia /1.9 SDI 64HP engine 2000 year/. Now the question is- What is better injection quantity for my pump and fuel saving? Factory setting is 3-5 mg/stroke.I had 1.6 mg and the car was so good i needed to use throttle less than 4.0 mg/ it is factory setting.The problem was vibrations and incorrect fueling.And second question is constantly i drive with 1000-1200rpm and 1700rpm without load where i shift higher speed.Is it good end fuel efficiency to shift around 1700 rpm or higher rpms.I thought that lower rpms are economically but i am not sure,board computer shows bigger values of fuel at lower rpms.Is it true.Also which way to use fast acceleration between 1700 -1000 rpm or slowly acceleration, sorry for my bad english .Thank you in advance.Best regards from Bulgaria

[AndrzejM]

First of all welcome to ecomodder!

That's not the best idea to mess up with fueling, it shouldn't be way different from recommended factory settings. So stick to 3-5mg/stroke.

Regarding fuel efficiency you should compare mpg for two different tanks, one driven one way second another. That will be the best way to answer your question.

Have you ever compared on board FE computer with the pump? Is there any difference? If your fueling was not within factory range your on board computer could show completely improper numbers.

[cecilio]

Yes i saw that board computer calculate moment and total fuel consumption with low values.When i put 4.0 mg/str. i saw higher fuel consumption moment and total.And i tried to realize how to increase fuel economy and i started to drive on low RPMs no more than 1600 but it does not solve the fuel consumption.I thought that low Rpms means low consumption but it is not the true. Thanks Andrzej

[cecilio]

i m going to try to increase the economy with higher RPMs .Vekke wrotes me and i will shift around 2600 and i will see the consumption.

[AndrzejM]

You know, fuel indicators and oem on board computers are set up for specific engine parameters. So if you change fuel dose for example your OBC will show wrong numbers, unless you'll calibrate it. So you should measure FE changes in a long term using odo and pump. Then you'll know the % offset for OBC. If it can be calibrated then do it, if not you have to remember the offset and count the true numbers.
Usually (unless for BMW) OBC can be calibrated +/-20% but if you change fuel dose from 1.6 to 4mg it won't be enough.

You may go for ScaGauge, UltraGauge or OBDduino as well and after calibration you'll see the exact numbers for FE of your Skoda.