Outer Limits 4x4 Board

Hi
just after a quick bit off feed back on what you think my fuel comsumption is like etc .
3.9 auto rangie , 91 4 door . Have 2' body lift and about 2' spring lift running on 235x85x16 road tyres .
I get 190 mile to a tank to fill of 70 litres , around town and 210 miles open road .

When I got it it has extractors on it and no oxy sensors . Beening a late model 91 ( gas fuller on upper rear panel ) i thought it should have them . If I got a part no off my ecu can anyone tell me if it sould have sensors etc .

Sheers
Chris

G'day Chris,

Sorry can't answer the Oxy question, haven't absorbed enough Rangie info myself yet!

Your fuel economy figures sound very similar to mine ('88 3.5 EFI 2.5" exhaust Unifilter auto) I get any where from 16L/100 to 20L/100 (more the higher than the lower!)

Your economy sounds about normal, perhaps a little high considering your on road tyres (I know muddies made my consumption worse).

None of the 3.9's on Rangies had o2 sensors, they are a very basic sysyem. The hot wire system that is fitted to the 3.9's is quite good though and a much more reliable unit that that crappy L-Ject systen fitted to the 3.5 Rangies.

Whoever put extractors on it wasted their money because the standard manifold setup is quite free-flowing anyway.

Regards,

Trav

Whoever put extractors on it wasted their money because the standard manifold setup is quite free-flowing anyway.

Ummm, I reckon you might want to check on that. There are appreciable improvements over just putting a free flow exhaust on if you then add extractors. Those Rover manifolds aren't that free flowing and it always improves torque figures if you have the secondary pipes (the final two on the extractors) as long as possible.

You are spot on if the exhaust is not changed as well. Just extractors will make stuff all difference.

On the fuel front, it does sound a little heavy to me. Your injection system is the 'hotwire' version and does not have oxygen sensors. In fact, your engine should be a 3.5 for a 91 model?

Hi
Yep it is a hotwire system which is good . Although considering going to a megasquirt if it will help on fuel cons .
Also its a factory 3.9 , i thought rangies were 3.9 from about 89 and the disco's about 91 ish .

Either way thats whats there ( and not there ) so just trying to find out if they had oxy sensors or not . I have heard some do and some don't , depending on the ecu . Was hoping putting one back if its not there may bring the fuel bill down a bit .

Will see what I can find out

Cheers

Chris

up2nogood wrote:

Whoever put extractors on it wasted their money because the standard manifold setup is quite free-flowing anyway.

Ummm, I reckon you might want to check on that. There are appreciable improvements over just putting a free flow exhaust on if you then add extractors. Those Rover manifolds aren't that free flowing and it always improves torque figures if you have the secondary pipes (the final two on the extractors) as long as possible.

You are spot on if the exhaust is not changed as well. Just extractors will make stuff all difference.

On the fuel front, it does sound a little heavy to me. Your injection system is the 'hotwire' version and does not have oxygen sensors. In fact, your engine should be a 3.5 for a 91 model?

The EFI manifolsd do go from 4 to 2 all the way down to the crossmember (on a 3.9 with the round tube style crossmember) and then join at the y-piece. All Rangies made from 1990 are fitted with 3.9 motors. The Discos got the 3.5 at that stage.

Those early 4 into 1 jobs like on my 83 are useless and bvery restrictiove and extractrs are almost mandatory, plus they leak constantly

Regards,

Trav