how to gain 7 mpg on a 15 year old 2.8l car

[kalniel]

But wouldn't it relearn anyway, even if you didn't reset?

[[GSV]Trig]

Yes eventually, but seeing as the injectors would be nearer original spec after cleaning its quicker to reset the ECU and take that back to original spec as well...

[Konan555]

That's asuming the O2 sensor is behaving

[[GSV]Trig]

Yes, or in my case the AFM, although having changed the CTS yesterday the car idles a lot better si the AFM might be off the list..

[badass]

Yes, or in my case the AFM

Any car with an O2 sensor will run in "closed loop mode" using the O2 sensor only during normal driving. The AFM will be ignored unless it's putting signals way out of spec.

[ehhhhhhh]

thanks for the post.

I wonder if I should get my injectors cleaned...My fuel consumption got higher by 0.5l/100km.

I also changed tyres recently and depending some info, tyres can have an effect on mpg...


How hard it is to remove these things? (I do the oil service myself...bit this seems a bit more complicated)

Also, as it mentions ECU reset I wonder if that would have an effect on the ECU mod? (sorry if it's a noob question, I'm not really familiar with these things)

[GoNz0]

injectors are eay enough to get out on most cars, just google a guide on it.

ecu mods are in the rom, adaptations are in flash ram.

if you have an ecu mod they reset the adaptations as due corse.

[Rave]

for the sum of £69 inc special delivery return to me i got all 6 injectors tested and cleaned, noticed an immediate 8mpg increase on the test run, car also idles better, accelerates a hell of a lot better and best of all more MPG

average b4 was 27mpg, now its 35

I'm well interested in this, what's his price for four injectors from my little 16 year old car?

I have one question though- are you getting your MPG figures from your trip computer?

I don't doubt that you're going to see a significant benefit in MPG and driveability from having injectors that work properly- but if you're basing it entirely on trip computer figures I suspect your actual gain in MPG will be less than the trip comp says. AFAIK trip computers work out MPG by comparing speeds to the amount of fuel the ECU is trying to inject. If your injectors were clogged and only delivering 90% of the fuel they were supposed to, the ECU will be thinking that it's chucking more fuel in than it actually is.

Balancing the fuel flow rates, and improving the spray pattern will almost certainly improve combustion efficiency, but by ~25%? I have my doubts. You may well be getting 34mpg now, but you were probably getting a bit more than 25mpg before.

I've never had a car with a trip computer. But I'm a geek, and I track volume at the fuel pump against mileage and am rarely surprised. My mum's diesel Clio did 45mpg around town. My diesel Mondeo and petrol 106 manage a pretty consistent 35mpg.

[GoNz0]

yes its the trip computer, you would have to email him for 4, i guess £49.

[yogibear]

Clean injectors are recognised to be vital for diesel - that's why the additives in premium diesels are basically cleaning agents (to the point where shell introduced them to their non-premium fuelsave brands too - dropping the diesel premium as a result).

I used supermarket diesel for about a month on my 3 series until I felt the effects, it was unbelievably noticeable. It was seriously down on power, mpg was down about 5 miles and even the turbo felt different probably due to the lack of power. Got some redex and started using Star and Shell no more problems.

[Apex]

Any idea if this guy can do diesel injectors ?

[GoNz0]

email him and ask, they have to be top entry and bottom exit to fit his rig though.