Nistune Forums

hi guys new to this just turboed my vl and getting it running right so it safe to drive

i have so far got it to idle good and have good afr's but it is very rich on boost but am running very low boost so will wind boost tomorrow and see how we go

main problem is when idleing if u stab the throttle really fast it dies and some times back fires but if you ease it past idle then stab the throttle it goes fine

using vlrb30et_b4903-mt base tune from rom pack and have not changed anything bar resize injectors

is there anything i should be looking for to find what it is

on lm1 when it dies it goes very lean on wideband

whats the part numbers on the injectors?
how much fuel pressure @ atmosphere?
MAF type?
post a picture of the engine bay and cooler piping.

what have you done so far?
or just post the bin file.

its a na block that has had a shim installed to de comp

running to4e high mount turbo 2.5in pipe to fmic 3in out 300x600x100mm fmic xf tb coustom intake. afm inline in cooler piping
running na injectors
tial 44mm waste gate
3in zorst

http://a7.sphotos.ak.fbcdn.net/hphotos- ... 0573_n.jpg

post your binary tune file and I'll fix it.

using this bin straght from rom pack

here is what would be a good starting point given,

Stock NA cam, na injectors, decompressed via plate.
check cam belt timing is 53 grooves notch to notch. (some w/shop manuals were wrong)
set the resistance between MAF pins 1 and 6 to 370-380 ohms.
set the ecu idle screw to the middle. (naturally, only if someone didn't remove it during nistune install)
set the idle ICM solenoid bleed to warm idle of 750-800.
set boost @ 6psi, the na injectors have no hope of keeping up with an NA let alone a boosted engine.

if possible, put the MAF back where it was, ensure it still has the two screens on it and install an airbox,
reestablish the idle control circuit plumbing to assist idle control,
put the XF MAF back on an XF, they aren't worth the effort and offer nothing.
the intake manifold design really doesn't promote good airflow, it's a good doorstop, stabbing the throttle could cause all sorts of port scavenging causing a pop/backfire.
try not to stab the throttle, it's not a speed density tune, not really designed 22yrs ago to do that very well. It will happily respond to a nice gentle womp of the right foot unless the MAF is FUBAR.

when you state "very rich" maybe show us a data log or some results. Boost vs RPM vs Lamda.
is that a malpassi fuel pressure regulator buried in the engine bay somewhere?
if so, depending on the ratio, it may cause challenges to control fuelling correctly.

let us know how you go.

set the idle ICM solenoid bleed to warm idle of 750-800.

is this the par that would be under my xf tb as that is concted but airline is not

was running 3psi but was running at 9.4 afr on boost and 13 to 14.5 at idel so we have set boost to around 6 atm

with the intake does that mean the rajab nizpro etc ar no dood as i had this made to use stock set up but frount mounting i can see how no: 1 would get better flow then no:6

and it did run fine as na tune with turbo with low at the start

thanks for in put as i will take as much advice as i can

will try your tune as soon as i can but cheap crap turbo off ebay lasted like 4 drives

so have orderd a gt3540r hope to have fitted and try tune by the end of the week

see if this works was one we done the othere night

the MAF looks dead.

one thing to note, if all you've done is resize injectors then your afm load scale (TP scale i think? i'm quite new to this also) needs to be adjusted also. we found with mine that it would hit the end of the load scale at less than half throttle, and cruise was just over halfway. that was resizing from 259cc to 444cc.

load scales don't change when injectors are changed.

If the boost was adjusted then load scales will need changing.
only a MAF change will readjust the load scales.

Previous versions we would tick by default to pull back the load scales during 'Injector resize' since TP wouldnt reach as far with K constant being pulled down. However normally when MAF is changed the TP then needs to go back up (but that is unticked by default)

Current default action on new versions is to leave both unticked, and then the user can manually rescale TP scales based on the max TP index during a power run

hi all

sorry for all the newbie stuff had not had much of a look at it all at the time
and was about 3 steeps ahead of my self lol

since walking away from it all for a a little bit I have found that I have a pipe missing from my cold start so I am going to block off as I want to remove all this on new intake

one thing I would like to ask when you load a map in as in a new one do u have to resize your injectors

my ATM it is way to rich on start up an stuffing plugs so going to set boost back at 4 psi and load vlt base map in so it is at least drive able on in and out of the shop while it is painted

Adjust the 'injection multiplier' whilst watching the AFRS on the wideband

Keep pulling it down until your AFRs are around 14.7:1 ish around idle and then slowly rev up and you want it transitioning about 11-11.5:1 to start when going on boost. See the tuning guide on our website for more info

Resize injector should only be used the initial time to dial the injectors in. That sets up this injection multplier anyway