Fuel economy, what you can do about it.

[Cubes]

I must be having a dumb day...........how does cleaning the injectors improve the fuel economy?  Surely a dirty injector flows less, so the fuel economy should be worse when it is cleaned and flows more.

The ECU doesn't know that the injector is dirty, it still opens and closes it according to the mapping.  In closed loop running, the ECU aims for 14.7, so it doesn't matter if the injector is dirty, 14.7 is still 14.7.

As I said, I must be just having a dumb day........

cheers 

<{POST_SNAPBACK}>

Below is what I visualise how a clagged injector could possibly increase fuel consumption.

Say we have a clagged injector or two that atomizes badly and flows less.

The O2 sensor only views the overall afr, not the individual cylinders.

As a result one or two of the injectors will be flowing less and atomizing fuel badly.

As a result, less fuel flow in to those cylinders is going to increase the afr that is seen by the ecu via the o2 sensor.

As a result the ecu increases duty cycle slightly to bring the 'overall' afr in check.

As I said.. That's the way I visualise the inner workings.

I would really like to know why some rb's are better than others on fuel.

My R32 has always been decent, changed to a bigger motor and its hardly changed, not to mention its always on boost due to the small turbo that is hanging off the side of it.

I'm almost scared to swap in some larger injectors. lol

Edited August 20, 2005 by Cubes

[emanuelt]

I finally got over 400KM on a tank of fuel, 409km and filled up before the fuel light came on. Thats a record for me!

Edit: I think the light flicked on for 1 second at some stage though. It does seem to slow up a little on takeoff with a full tank ,all that extra weight.

[AlexCim]

BEFORE the light!

WOW!

I get to about ~380 and then the lights on/off a lot, then at about 400 i get it always on and the car doesnt start very easily on a slight hill

Then at ~410, i fill up and put in 63L's

I know i push it

[Tangles]

Well, just filled up. 1st FULL tank Ive used since the dynotune service with new O2 sensor.

55.8L filled it right up to max, and did 391.5km for that tank. The fuel gauge light was just starting to flicker.

That equals exactly 7kms per litre, or 14.3L per 100kms. And I was certainly using 'boost' during this 391kms!

Edited October 3, 2005 by bwilkeson

[-FUZZY-]

Do u need the hand controller with the jaycar DFA???

and is there any advantage in getting a SAFC over this?

Edited October 4, 2005 by NRGIZD

[AlexCim]

NRGIZD, like i said, i have a DFA here and built which i wont be needing anymore due to getting a power FC, they RRP at 79 in kit form, and i dont mind giving mine to you at that price built.

You will need the hand controller with it too, but they are pretty easy to build as well (i need to keep my controller for my EBC)

The DFA is also pretty easy to install, and i can also just send you right to the person that was going to tune mine with me Dr Drift.

[Tangles]

Grab the SAFC-2 off ebay, for under $400 brand new. Cant go wrong with the Apexi...............

[-FUZZY-]

Grab the SAFC-2 off ebay, for under $400 brand new. Cant go wrong with the Apexi...............

<{POST_SNAPBACK}>

See thats what l was thinking, esp as the workshop l use know them very well.

Might have a sit and think on it, are the hand controllers hard to assemble?

[s.m.park]

When I first bought my stagea I was getting about 300km to 50ltrs not going over 3000rpm. (Mixed Driving, Sydney & Freeway)

Then autostyle did a service and changed spark plugs, O2 sensor, high flow filter eliment, cleaned all the throtle body, injectors, fuel filters, etc and now I'm getting about 450 to 50ltrs. Not hooning but not granny style like previously.

I also drove to QLD and was achieving 560-600km to 50ltrs.

Car is still facotry standard other than the high flow air filter element.

[ian]

When I first bought my stagea I was getting about 300km to 50ltrs not going over 3000rpm. (Mixed Driving, Sydney & Freeway)

Then autostyle did a service and changed spark plugs, O2 sensor, high flow filter eliment, cleaned all the throtle body, injectors, fuel filters, etc and now I'm getting about 450 to 50ltrs. Not hooning but not granny style like previously.

I also drove to QLD and was achieving 560-600km to 50ltrs.

Car is still facotry standard other than the high flow air filter element.

<{POST_SNAPBACK}>

Given that is the first post by that ID, and their link is straight to autostyle, you have to wonder about how genuine that comment is.. Care to comment about what your association with them is, and what stagea you drive?