Tephra,

How is logging with orig map base and new tank of fuel? Knock gone?
I know its the middle of the night there, tell me when you get up and have time.

 

If your almost positive it is bad fuel, why not use a bit of octane booster/enhancer and call it a day?

 

ok ive filled up (52L) with fresh tank, same company (Shell VPower) different station (high volume station at end of weekly price cycle).

Here is the resulting pull (this was done in slightly warmer weather 5-10C higher than the previous pulls:


Same tune as the last two pulls on https://www.evolutionm.net/forums/7943832-post47.html

So a bit richer 3300 through 4000rpm... Can fuel cause AFR changes? Obviously different brands of fuel = yes, but same fuel but bad quality???

 

Before I load my previous tune on, I need to know if anyone has any data on what affect on AFR a HFC will have.

a friend that does tuning sent me two ROM's: one for catback, one for for dump back... the dump back tune is 0.25pt AFR richer in the fuel map.

thats all I got..

anyone?

 

well at least it looks like you know what's wrong now!

 

well not entirely...

 

weren't you getting high counts of knock with that tune as well?

 

recap:

1) initial tune was fine for several months - no consistant knocking
2) one day last week I picked up some bad knock when downshifting - thought it might just be I hadn't hit that part of the map before
3) added 3" down pipe + HFC
4) bad knock during spool for pulls
5) added a bunch of fuel (1pt in the map) and swapped relay = knock went away
6) refilled today and knock still gone

my next step will be todo 3/4 back-to-back pulls to make sure knock is gone...

then I will swap the relay back and do some pulls - if that results in knock, then I guess the relay is bogus..

if that doesn't result in knock, then i will load up the original tune + 0.5pt in the fuel map and do some pulls, if thats ok then take a little bit more fuel out (get my AFR back to 11.5) and retest...

 

Tephra, might be wise to actually test the relay (apply 12V, continuity) before subjecting the car to knock. The relay thing is a known problem (although not necessarily the problem in this case), no need to poke the sleeping bear.

I have a spare green relay, if you'd like me to send it to you. It may take 7-9 months to get to upsidedownland, but I don't mind!

 

yeah exactly, I don't want to discover knock hehe

I did the highbeam swap test, and that didn't show anything. I guess I can do the ohms test as well.

I might try and get a couple of the "new blue" relays from the 2010... But I want to try and confirm it is indeed the problem

 

Shell has been converting to nitrogen enriched fuels around here lately... not sure if they are doing it there, but depending on the qulity of the blend it can cause variations in your fueling. Also differences in ethanol content if you guys have the ehtanol 10-15% blends like we get here..

 

good point... /me goes to check shell.com.au

 

nope nothing useful... nothing on google about shell AU doing it either...

 

do they add ethanol to yoru fuels there? It varys here from tank to tank.

 

They do, but only for cheaper fuels... and they have to tell us about it.

That said I don't think Shell VPower (98ron) has Ethanol...