Thread: Increased Fuel Consumption - 3.9 V8 D1 Auto

1 Clean MAF with electronic contact cleaner spray into small hole .
2 Check vacuum advance by sucking on hose and seeing if it sticks on your tongue. If no suction replace vacuum advance
3 check centrifugal advance by seeing if rotor turns a little bit then springs back. if not remove rotor and screw underneath and drip oil down.
4 check resistance of temperature sensor to see if it below 400 Ohms at operating temp. If not replace temp sensor
5 note position on gauge of temp at operating temp. If down near blue segment change thermostat.

That is a good start along with new plugs , leads, rotor and dizzy cap. make sure you get a genuine "Lucas " branded rotor. have you EVER replaced the dizzy cap? they are wear items and should be replaced every 160KK or so.
Regards Philip A

Thanks for the suggestions. I should have also mentioned that the engine is fitted with a Unichip.
I can't recall ever having replaced the distributor cap.

Well forget the vacuum advance bit if the unichip has taken it over, but the rest is still valid.
While some on the forum say Unichips lose their map, I have not found this to be so, as I had mine tuned after 2 years and the original maps were still there and going strong.
Regards Philip A

It could even be something simple like a dirty air filter, I presume you would have checked it though.

20L /100kms is what I get driving like a princess around town.
And thats after all the stuff suggested above. I get it down to approx 16.5L / 100kms on highway cycle. They're all different I suppose.

Originally Posted by Gooner

20L /100kms is what I get driving like a princess around town.
And thats after all the stuff suggested above. I get it down to approx 16.5L / 100kms on highway cycle. They're all different I suppose.

Craig...a Princess! never, Regards Frank.