overfueling

[wazo]

what is it and how do i over come it ? and what effects does it have on a 20vt

 

[gavthelad]

Mine was over-fuelling when i had revo turned back on and had it rolling roaded......Noticed that when it was coming on boost i started to get a bit of a misfire, changed the plugs for Denso IK22's and its the best its ever been!! No misfires now, pure power all the way through the rev range and £35 lighter in the pocket! Worth it though, havnt had it rr'd again though so dunno what my fuelling is like now?...

 

[acidstrato]

thats not really over fuelling though, it was misfiring cos the plugs werent providing enough spark

 

[acidstrato]

dodgy lambda or maf could cause over fuelling

symptoms could include abit of smoke out of the exhaust, lots of popping and backing (although i get this anyway from my exhaust)
and almost certainly a fault code..mixture too rich or something

 

[gavthelad]

yeah i get the pops from the exhaust sometimes on gearchange, surely if the plugs aint sparking enough, there is excess fuel not getting burned hence the rich mixture that it indicated on the r/r???? Wouldnt this be a type of "overfuelling"?

 

[acidstrato]

i see that your trying to say but over fuelling is more down to the engine management system not adapting the fuelling for the air - fuel ratio hence the engine gets more than required

your problem was more like the correct amount of fuel was being injected but not all of it was burned because of the lack of spark

 

[gavthelad]

Yep, im with ya

 

[wazo]

whats the measuring blocks for checking the maf and on a remapped ibiza what should the reading be

 

[acidstrato]

003
dependent on map it should be over 140g/s 150-160 is a good result

 

[wazo]

cheers ill go and run vag-com now

 

[wazo]

ok just run vag -com MEASURING BLOCK 003 results are
RPM-840/MIN
MASS FLOW-BETWEEN 2.69-2.73
LOAD 2.4%

one fault code secondary air injection P0411-35-00

 

[PhilW]

So you just looked at the g/s on idle?


You need to put it in 4th, low rpm to redline and log that.

 

[wazo]

yeah i realise that now just done a search im new to vag -com

 

[acidstrato]

no problem try again fella, as Phil said, low rpm to redline in 4th although in my experience for just a maf check its ok to use 2nd gear (this way you aint doing silly speeds)

 

[wazo]

ok did a vag com check in 2nd gear to redline tonight maf reading between 135 146gs

 

[acidstrato]

thats not too bad really could be better but certainly aint low

 

[Craig!]

Mapping, lambda, suspect MAF. Am I right in thinking your running the BAM engine? If so 146g's is very low...

 

[wazo]

im running an AGU engine with a large port head - jabba remap after my AQX engine exploded on me im gonna change coils/plugs lambda and maf clean out the dynatwist in the next few days then ill give it another try

 

[T7ODD]

How do you know it's running rich Nick?

The secondary air injection is probably a vacuum hose. It could be a fault from ages ago though, my Engine light came on when I had that fault and went out when I found the faulty hose. It might be from back when you did the bypass or even before with the old split rubber hose, but even so, it will remain in the faults log until it's cleared. Clear the faults and see if it comes back in a few days.

 

[jNx]

I logged block 031.

If the 3rd colomn is 1.00v thats good mixture. 1.00v+ is leaning out and 0.80 to 1.00 is rich but good rich. Anything less than 0.80v is bad!