Very bad fuel consumption

BUDDIE95

MEMBER
2004 HOLDEN RODEO
3.5L
6 CYL
2WD
MANUAL
180,000 MILES

Hi all, I have the vehicle listed above (RA) with motor and 5 speed manual transmission. I have owned this vehicle for about 2 years and for the entire time it has had very bad fuel consumption i.E. 6km to the liter or worse.
The vehicle has had new plugs, air filter, fuel filter, the MAF sensor has been cleaned and there are no vacuum leaks that I can find. All the grounds have been checked cleaned and tightened and it has been on several diagnostic machines with no errors found except that sometimes it's reported that the left rail has high pressure.
The vehicle also occasionally cuts out after hunting when you stop at a red light or stop sign etc.
Can anyone suggest how I can improve the fuel consumption?
To put it into perspective - it has a 76 litre fuel tank and I can't get 400 km out of it unless I'm on the highway.
Thanks in advance for any help you can provide.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

This is a tough one. You have replaced most all common causes. However, have you check to see if you have any brakes hanging up and causing a drag on the vehicle?

As far as the fuel pressure, I would recommend checking to make sure it isn't too high. Here is a link that shows in general how it is done. You will need a fuel pressure gauge, but most parts stores will lend one to you.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know what you find or if you have other questions.

Take care and God Bless,

Joe