Poor Fuel after Rebuild

ZippyZafira

Hello Guys

I back again with more annoying questions LOL

I have been working on a lot of Zafira's here in AU and did a full rebuild on my own but im experiencing some big difference in fuel consumption

Most of the zafira's here that i work on or own are running fuel 7.8 - 8.6 Liters / 100kilometers (dont ask me what this is in gallons and miles as i would not have a clue)

I did a full rebuild on my own Zafira 4 mths ago and im not happy with the fuel of it as it now runs as 10.8 - 11.2 liters / 100 kilometers

Now to me this is a massive jump in fuel consumption

here is what i did
Boar the cylinders 20 thousands of a inch (larger pistons and new rings obviously)
Boar was cross honed
Block Shaved Flat
Crankshaft ground (big ends 20 thousands of inch and mains 10 thousands of inch)
New bearings to suit both mains and big ends
Head Reconditioned "new valves and valve seals)
Replace Air filter with K&N and removed filter box sock
New GM genuine spark plugs
New Fuel Filter
Pre Cat drilled out
New balance chain kit
New Timing Chain Kit
All New gaskets through out the motor

Now i know there would be a slight difference if fuel because the boar is slightly bigger but not enough to get 30% less fuel economy

Now can anybody explain what they think could be the cause or do you think this is normal?

the car is running PERFECT just costing a lot more in fuel

Fonzz

K&N'S are thirsty mate, mine drinks fuel with it on, and considering you were used to standard air box, id say that this could be to blame

Matt

7.8 = 36.2mpg
8.6 = 32.8mpg

10.8 = 26.1mpg
11.2 = 25.2mpg

I can't see a K&N filter making that much of a difference to the consumption.

mazza_2_2

Nor can i see K&N making that much difference either.
They are higher flowing and so therefore in fact you don't need to apply as much throttle in order to achieve the same acceleration as with standard airbox/filter set up. Only a heavy right foot would give those sorts of economy figures with a K&N filter.

Is the engine running even slightly rich?

sandyc

If the car was lying around for a long period of time make sure none of the brakes are binding or sticky.

ZippyZafira

hi again

Yeh i dont think the K&N can be the blame for such increase. The engine is running perfect not sure how to tell if running rich but i do have a OBD11 reader.

in regards to the brakes the are new i did them also so i doubt that is the issue

MikeS

in this country we pay 6.5 gbp per gallon = 10 AUD

i get around 30mpg going to work and back - 8 mile short trips below 30 mph

i never seen a z22se do above 35 mpg unless it is mostly motorway driving as they are quite a thirsty engine stop / starting

anyway in this country doesnt matter if you drive a 1.0 litre tin can or a 2.2 you get shafted with fuel costs - getting to the point where if you want to save on fuel prices dont drive

her eis this countries fuel prices

http://www.speedlimit.org.uk/petrolprices.html

atm sitting at over 142p a litre