Better Fuel economy

[hudson44]

I've done a couple of things to my NJ 3.0lt V6 recently which have really improved fuel economy and i thought i'd share them with you guys. I put 100lt in her the other week to do a fuel economy test and i got about 620km to the tank which is roughly 16lt/100km, a big improvement on the 20-22 L/100 which it was doing before.

Firstly i replaced the oxygen sensor with a universal 4 wire which set me back about $75. The other two are performance mods, so to speak, but also helped in fuel economy. I've just done a ball joint flip and the bars are reasonably cranked with the bump stops chopped so the CV angles are quite large. I was sick of replacing CV boots every 12 months so i fit a set of AVM manual hubs while doing the CV's this time around. From memory they set me back about $95 for the pair. This obviously causing less drag.

I also fitted an airtec snorkel which i've wanted for a while. Fortunately i work at TJM and got a good price but i think they retail for around the $450 mark. I also fitted a Finer Filter which we had lying around work.

This may sound excessive cost wise and will take a while to recover costs in fuel savings, however the way i look at it is i'm only out of pocket the Oxy sensor as the other 2 were offroad performance mods i wanted to do anyway. I think 16Lt/100km is not bad for these old girls and it keeps the wife happy as well as she drives it every day. The look on her face when she saw all the holes in the RH front guard when i was fitting the snorkel was priceless.

[-Scott-]

The look on her face when she saw all the holes in the RH front guard when i was fitting the snorkel was priceless.

Is that the pic in your avatar?

I've been thinking about replacing my O2 sensor - can you post up the part number and the wire colours?

[hudson44]

I've been thinking about replacing my O2 sensor - can you post up the part number and the wire colours?

It was an ACA number. Will have to ring my supplier for part number as i did it a few months ago and its covered in mud already. The wiring was pretty straight forward but will have to jump under the car for colour codes. There is a direct replacement one by Bosch i think, but its twice the price, just for a oem type connector.

Replacing the O2 sensor made a big difference. When you think about it they are a servicable (replacment) item as exhaust gas passes over them all day every day and mine was 14 years old. I think bosch recommend any O2 sensor be replaced every 5 years to maintain optimum fuel consumption and economy.

The only drama i had was that the thread was damaged when i pulled it out as it has fused over the 14 years it was in there. Luckily i had a tap at work and cut a new thread. Worst case scenario is to replace that small section of the bolt on engine pipe.

[bn_sil80]

I did my o2 Sensor the other day. Heaps better fuel economy. It's easy to fit. 10 minutes with a multi-meter and solder. 2 black is heater (non polarity sensitive) one earth, which I THINK is green, and yellow which I THINK is ECU feed.

[J Top]

Apparently O2 sensors have an air bleed hole which can block up with mud so maybe even just a regular inspection/clean would help

[-Scott-]

Apparently O2 sensors have an air bleed hole which can block up with mud so maybe even just a regular inspection/clean would help

I don't know where you got that from, but it's news to me! Got a link?

[Dexter]

Apparently O2 sensors have an air bleed hole which can block up with mud so maybe even just a regular inspection/clean would help

Wouldent that mean that you always had an exhaust leak?

Also you can check if you O2 sensor is working using a digital multimeter, just need to expose one of the wires.

[mccpijs4]

20? 22? Jesus, how could you afford to run like that?

I get 13-14 in my '91 shortie with 33MTs - granted I drive like my grandmother to achieve this....

[bn_sil80]

I think the air bleed ones are used in high mount turbo applications from memory

[smccask]

it is true, all oxy sensors need to have atmospheric conditions on the inside of the zirconia cell, they generate a voltage that is related to diff in oxygen content inside to outside of cell. it prob is possible to foul them so bad they block right up

[smccask]

quick look on the net seems to suggest most vent at the cable gland

[hudson44]

I think the air bleed ones are used in high mount turbo applications from memory

I've been a mechanic for 10 years, replaced many O2 sensors and never come accross any with bleed valves. Thats not to say they aren't out there but i don't see a point or need for bleed valves. To bleed what? Exhaust gases?

[smccask]

some of them do in fact have air holes (no bleeding invlved), that are literally little circular ports for air reference to atmosphere, i'm no expert, just read bosch website out of interest. Bosch themselves suggest one mode of failure is oil contamination _from outside_ thus blocking air vent. Bosch also say not to use cleaning fluids or grease on outside for same reason.. i guess excessive mud may be just as bad.

they do say that their most recent models have an advantage of now being completely sealed, so they must store the reference oxygen inside