Vl Fuel consumption

[damankerrison09]

Probabaly been covered a million times but i couldnt find anything.. Anyway I got my 5 speed VL, exhaust extractors and mild cam. Now babying the shit out of my i get roughly 18L per 100km...

Now thats bad! Before i had the cam it was about the same, i know vl's are bad for fuel economy from other people's post's that i have read on here in the past and this 18L per 100K seems about right.

When i looked my car up on redbook it said the 5 speed's should be down around the 10L per 100km's?

Is there something i'm missing? is there a way to improve this fuel economy?

Keeping in mind i have had it serviced and tuned in the past and not alot went better haha

[Jezza]

well im not sure exactally what my economy is exactly but i know that my fuel gauge reads around 1/4 less then what in the tank, but i roughly would get 300 - 350kms if i tried running it to empty

[detox_nath83]

depends on how u drive bloke.....
and what fuel and your tune,,,,
also what subsystems are running to spec........
so theoretically all vl's are different...
rich could be, vac leak, afm adjusted wrong, O2 sensor kaput etc etc

[VL_5SPEED]

just clocked 400k's and still have a quarter of a tank left. VL turbo manual.

[damankerrison09]

See thats what i mean, VL_5SPEED Obviously has alot more power than me and a turbo and he's getting more than me and VL3.0L? And as i said i got that figure babying the shit out of it. Shifting at 2000rpm, not taking of in a hurry, no skids, no anything!

So how would i check to see if i can get anything better? Vac leak as in all them little hose's on the manifold and such? and how the F#*K do you adjust or correctly adjust an AFM, arent they just set?

[detox_nath83]

All here bloke

1. Air flow meter: check the connections including rubber boot, clean with contact cleaner if necessary. remove the airflow meter (undo the clamp behind it and remove the top of the airbox and air flow meter together) and clean using contact cleaner or some other cleaner thats safe on electrical components. clean out the airbox and replace the air filter if necessary ($10 for a cheap one, $100 for K&N) reinstall everything

if the car is stalling after starting or seems to be choking still after this, check AAC valve, air regulator, make sure there's no air leaks, then replace the air flow meter ($20-$60 from wreckers, approx $150 reconditioned, about $400-$600 new)

TO CHECK AND ADJUST MIXTURE:
1. start and run the engine until its at operating temperature
2. set idle speed and timing to specified values
3. take off the passenger kick panel to view the LED's on the ECU
4. start and run the motor at 2000rpm for 2 mins
5. check the flashes from the LED's on the ecu while at 2000rpm, they should both flash together more than 5 times every 10 seconds. if they don't you have ecu or oxygen sensor issues (refer to the picture at the bottom explaining the interpretation of flashes other than what are stated)
6. if there are more than 5 flashes per 10 secs, stop the engine, disconnect the wiring connector from the AAC valve and the throttle switch
7. start and run the engine at 2000rpm for 2 mins
8. let the engine idle
9. the leds should now flash simultaneously
10. if the green light is flashing more the mixture is lean, if the red is flashing more the mixture is richer than it should be.
10. if the LED's do not flash together remove the plug next to the Air flow meter connector and adjust the screw until they flash together (clockwise raises the resistance and leans the mixture, anti clockwise lowers the resistance and richens the mixture)
11. replace the plug, replace the AAC and throttle switch connectors and return to instruction 4. do the test again to check that the mixture is now right
12. if the mixture cannot be adjusted so that the leds flash together, its time to test the AFM

TO TEST AFM:
pull back the rubber boot on the AFM connector revealing the wires. grab your multimeter and stick the probes on wire 4 (white) and 3 (1 being the closest to the airbox) with the multimeter on DC voltage. turn the ignition on and the voltage reading should be between 1.26V (lean) and 1.32V (rich). this is the base setting and if it is out then the AFM wont be able to be adjusted to a satisfactory mixture (meaning you need a new one)

and just for interests sake you can test the mixture by putting the probes on wire 1 and 3 with the key on and measuring the voltage. 3.6V is the factory setting which is lean, with 2.0V being rich. the mixture should be in the vacinity of 2.0-4.0i couldn't get the LED's to flash and therefore couldn't set it using the computer so i did it this way and set it to 3.5V (AFM resistance of 375 ohms) and then checked it using the computer and it was right, LED's flashing together.

Goodluck man

[damankerrison09]

Holy **** me jesus! Now i gotta do all that shit! Far out thanks heaps man where the **** did you find that haha, I'm guessing manual somewhere.. I can see myself getting very confused but i'll get it eventually.

My issue it i cant set my timing and i dunno how to adjust the idle speed, you see i have a cam now. And my mate snapped two bolts that hold the lower timing cover on which has the timing marks on it, mechanic tuned it by ear and its pretty darn close.. Ill have to get them bolts out and replace the timing cover before i do this.

But thanks man!

[damankerrison09]

Hey, I just checked the mixtures and they are flashing at the same time Turns out the AAC plug was unplugged already! Car idle'ed alot better now that its plugged in :

Just a question, besides the idleing funny.. What other sypmtoms would this have caused, added fuel consumption maybe? Anything else?

Cheers

[Jezza]

well i did a test and drove 100km from a full tank and then topped it up after it reached 100 and it needed 21.41L so my fuel economy is SHOCKING

[Tree cutter]

Faulty temp sensor will cause bad fuel economy.