10 replies to this topic

[KiwiMR2]

Hey guys

My 96 SPI is running rich & my fuel consumption has become quite bad.

I believe my oxygen sensor could be faulty but before I go down that road is there any sensors that I can unplug & check to make sure they are clean etc?

Cheers
KiwiMR2

[BoyracerAU]

That little sensor in the air filter affects fuel mixtures. You could give that a shot.

I've read on non Mini forums that people have had success with cleaning Oxygen sensors. Although, for all the trouble it is to get them out, I don't think I'd waste my time. Much easier to stick a newie in and be done with it!

[KiwiMR2]

It's worth a shot

I'm only getting around 270 km's off a full tank (167 miles for the pom's) on 98 octane.....worse on lower octane.

I'm sure I was getting better fuel consumption than that when I 1st got it.

I seem to have noticable flat spots when she's cold as well.

I'm thinking the oxygen sensor is shot.

Cheers
KiwiMR2

Edited by KiwiMR2, 06 May 2008 - 08:21 AM.

[mogg]

I have the same issue, and maybe getting a bit less mileage than you. You might consider reading the "Rough on Cold" topic. I think there is more to it than an oxygen sensor, mine tested out fine. minisport has a pretty good deal on them... Does the car surge (idle up and down when cold)?
some other thoughts..

looks like you have the big wheels, I do too, and they are less efficient. You also have an aero kit right? I have a roof rack, and I can feel the impact on air displacement on the freeway. maybe you some drag from the kit..?

a vacuum leak or intake manifold leak could create a bad mix of fuel/air, thus leading to bad mileage. it seems that this would be more noticeable if the overall running condition, but i am not sure how noticeable.

I recently replaced my air sensor in the air filter, when I get a mileage read I will post it here. I am curious if it changed any.
Of course the coolant temp sensor would also have a large impact on gas mileage.

These are the most obvious things that come to mind.
last time I checked I think I was about 25 - 28 miles to the gallon, what I have read here in the forum suggests I should be getting far better, But I am not entirely sure. I have a crypton unit and everything checked out fine. I would love like to get better mileage, it's a bit embarassing at the pump having a guy in a SUV ask what kind of mileage you get knowing he is not far off that mark. I usually must bs a bit. I would be very open to test out and hear any other suggestions..

[KLAS]

a very worth check would be if the oxygen sensor heater is working.
i found out after replacing every sensor in my SPi, was running rich at TÜV (like your MOT), that the wire that brings power to the relay was heavily corroded

[Bevan]

Oxygen sensor can be a pain to remove sometimes, be carefull as they bend and are about £100 for a new one. I had an ail leak from my manifold which gave me very bad fuel consumption.

[mogg]

27 miles per gallon. thats around town, no highways.

[mogg]

checked out the heater to the oxygen sensor. getting voltage, no signs of corrosion. Any other ideas for better mileage? thanks KLAS for the good idea and photo.

[ICAM]

Have u check your air filter? when did u replace them?
Sometime people forgotten to go to the basic step first.
Also check your spark plug condition.

[KiwiMR2]

Hey guys

Some good advice there....I think I'll get it looked at this week.

Does the car surge (idle up and down when cold)?

Nope....idle's fine. Main thing I notice when it's cold is the flat spots - once warm the flat spots tend to be less noticable.

looks like you have the big wheels, I do too, and they are less efficient. You also have an aero kit right?

I have the OEM SPI Cooper wheels, no body kit.

The sad thing is here in NZ very few have had experiance with Rover Mini's.....I'll use the guy who fixed my ECU way back in the begining & I'll give him all the info you guys have provided so he can work through that lot )

Cheers
KiwiMR2

[OJM]

How did you get on with this? Sounds like a similar problem I'm having on my SPI.