Adjusting fueling

[Chiffs]

Car has the usual prob of high idle:doh:

Have spent days trying to sort this and changed many bits like.

new temp sensor
air leaks
new lambda
seting idle control screw
re-earthed maf
plus what ever else i cant remember.

Main thing being it smell rich at idle and its mot time soon:doh:

I have a blue emanage fitted but not mapped therefore it runs the standard ecu settings.

I can adjust the timing and fueling with this.

by reducing the fueling it bring the idle down but still smell rich:doh:

would advancing or retarding the timing give better emissions for mot?

can go either way up to 20 deg.


any ideas?

 

[Rishi]

Look to see that you still have all 4 rubber stoppers/caps along the butterflys... People tend to lose these which causes a high idle...

Also check the lamda...



Rishi

 

[Chiffs]

lambda is a month old and done checks and all working, rubber caps all there too

 

[Rishi]

Use an AFR gauge with wideband, plug in the laptop with emanage software and then look at the AFR at the idle load sites... See if its reading rich and then adjust the fueling accordingly...

Double check for leaks, ignition issues etc before doing the above... Because you don't want to adjust a map to mask a problem...



Rishi

 

[Chiffs]

only want to lower it for idle just for the mot.

want sort of afr on wideband should the R sit at when idling to pass the mot emissions test?

need to find somewhere with a wideband too.

 

[AJ4]

14.7 : 1

The emmisions test is also done at around 3000 rpm to check the operation of the closed loop lambda sensor so if its running rich at idle it will also run rich higher up.

 

[campbellju]

I've half followed this buyt not taken too much notice so apologies if I'm pointing out stuff you've already done.

I think I read you checked the lambda operation, its a new titania Lambda so you can assume this is good?

When you adjusted your idle control screw, was the TPS disconnected? On my car the screw is all the way in.

In the manual there is information about adjusting the MAF reading but I woudln't get into this yet.

We might be attacking more than one problem here. The smell of fuel could be from the ignition system not firing properly. Tming can have an affect but at idle it should be 20, use a light to check it and then look elsewhere for causes.

I have ended up earthing everything on my car to solve my PFC problem and if I were to do it again, I would still cleam (quick dremel to lug and body contact) the Lambda earth (driver front), ECU earth (Engine top), Main Engine earth (Front left Engine) and battery earth (Battery to body). This gave me 100rpm or so

The previous owner had also poorly removed the emissions control. The valve at the back of the rocker cover was venting to atmosphere and adding. Blocking this off (can of worms but ignoring that for the moment) reduced the revs a good couple hundered rpm.

If I can think of anything else I'll post up but I'd best get on with some work.

Jim

 

[Chiffs]

Have added extra earths already, one onto inlet manifold, one to block.

Timing set to 20deg

Idle screw all the way in and tryed that with tps disconnected.

Even had the emission valve thing of and looked inside it and have tensioned the spring a bit as it was not holding the flap shut
http://i2.photobucket.com/albums/y10/chiffers/gtir/DSC00429.jpg
http://i2.photobucket.com/albums/y10/chiffers/gtir/DSC00426.jpg
#This did improve the idle, by doing all these things, dropped it from 1700rpm to 1400rpm.

might take that valve of and block it up

 

[campbellju]

Have you borrowed smoeone elses MAF at all and tried that?

As you've got a closed loop lambda, you could always try re-calibrating that?

 

[Chiffs]

Not tried one yet only re-earthed it , will try a different maf.

How do you recalibrate the standard lambda? Didnt know thats possible

 

[campbellju]

Standard MAF, not Lambda. There's a plastic bung that you can drill out and there's a screw underneath. Never tried it but there is a section in the workshop manual on how to recalibrate.

 

[AJ4]

theres also an adjustment screw on the back of the standard ECU which is supposedly for idle lambda adjustment... never been able to confirm if its true or not though.

 

[Chiffs]

Thanks guys will check both over weekend and post outcome.

Will check ecu first as that sounds like it maybe the easiest to do.

Campbellju you dont happen to have the page number to save me spending ages looking through.

 

[campbellju]

EF-EC400 & 401 of the first service manual for MAF checking and adjustment

 

[Chiffs]

afm dont have the bit with the cap on, must be uk thing only.

There is a small screw type thing on back of ecu but dont seem to do anthing.


However i thought about adjusting the butterfly rods, made idle lower, but cant go any further due to stops.

Next job being loosen the stops, guess a small air leak through the butterflys really screws the idle up

 

[nitrosgti-r]

leaky dump valve?

 

[darkyGTI-R]

Look to see that you still have all 4 rubber stoppers/caps along the butterflys... People tend to lose these which causes a high idle...

Also check the lamda...



Rishi

I have the 4 butterfly vacuum line mod going straight to my bailey dump valve lol found it off mighty mods on youtube that was one of the first mods i ever did!