Nistune Forums

hey, so im having some trouble with my s13 and im just gettin fed up with it by now to be honest :S

i am still quite a newbie to the tuning world so please excuse any dumb questions

my problem is when i enter hot running conditions, it floods the engine when i let it go down to idle it doesnt catch idle and just dies, and the plugs will be wet afterwards...my afr measured on aem wideband is 14,4-14,7(idle-2800 rpm) when the flooding occurs and the lambda reads 0,99-1,00 so i dont get how it floods...

theres is an idle problem when heating up aswell if i give it a little gas and then let it come to idle it will fall to 500 rpm then catch on again and go at a steady 900 rpm at idle gets worse as it warms up to the point of flooding, and of course i cant really drive it anywhere as it wont fire backup after this happends.

injectors are fine it will hold fuel pressure at 3,5 bar for 10 min after i turn off the car if i clam the fuel return line so they shouldnt be leaky
the engine has been rebuild, so compression, HG trouble and so on isnt an option
CAS splines are fine
new coils and plugs, and spark looks fine (battery is showing 10,5+ volts when cranking)

my mods are:
gt2860rs
444 gtr injectors
z32 afm
hks filter
apex FMIC
apex flywheel
nistune of course
adjustable FPR
oil cooler
wallbro pump

engine has been honed, acid bathed new bearings all round valves checked and new rings and pistons. new gaskets and seals all round

any advice or ideas would be greatly appreciated

Try this file out (attached). This is tuned by PL and came from my mates S13 CA18DET with Z32/440CC proven working and dynoed

What pressure is the fuel regulator set to during idle when you are having issues?

my fuel pressure is set at 3 bar during idle.

willl the base timing cause any problems? just thinking that mine is a EDM base timing at 15 not 10 like the jap spec im assuming this is tuned for?

and why arent the main/knock maps the same in this tune? as i understood they should be kept the same?

cheers for the input matt

just a quick note to the fuel pressure: standard fuel pressure at idle for ca18det is 2bar (and 2.5bar with enhine off), so you are running 1bar more as standard for this engine...

ohh was told 37 psi roughly 2,5 bar was std, and since the gtr injectors 444c was given at 3 bar i decided to run with that and just adjust the k-constant to make up for it and make sure the gas is being sprayed properly.

how ever thanks for the info will try setting it at 2 bar and see if this changes anything

dont be confused by fuel pressure, you can run any fuel pressure as you wish, but this can lead to some complications with fuel tune....anyway, for your configuration is really no need to run any higher fuel pressure as standard...for me it looks that you K is just too high.... try to adjust it at idle, but first adjust injector latency to about 4D hex. Then tune your K to achieve about 14:1 at idle....this should give you about right K. Another important point is TP scale of fuel map...try to blip throttle at neutral, if maptracing jump directly to the right part of map, rescale TP... or try to use binary from Matt, but again, I would say that its tuned for standard fuel pressure....

the latency value 4d hex? :S mine is set 770 as the gtr injectors should be 7,71 ms if im correct?

maptracing seems to go very well with TPS/rpm

will look it all over tomorrow though cheers for the input, its appreciated

illl the base timing cause any problems? just thinking that mine is a EDM base timing at 15 not 10 like the jap spec im assuming this is tuned for?

The base timing should be 15 degC BDTC (as per 39F00 base image idle timing in the maps)

That obviously wont affect fueling issues. Correct the fuel pressure and 770uS is correct for 444CC injectors latency

Matt wrote:Try this file out (attached). This is tuned by PL and came from my mates S13 CA18DET with Z32/440CC proven working and dynoed

What pressure is the fuel regulator set to during idle when you are having issues?

HI Matt I open the bin file and notice that the tp scale is only 69 in max, I made a map for my car with the same setup and pass the 69 tp when got around 3500rpm the k in my bin was 412 and in this is 400 so not a big difference I think.
is there more tp scale hided and more values to the ignition and fuel map that aren't showing?

hey peeps, i am very sorry the problem wasnt nistune related i simply had an IACV that was stuck cleaned it out and runs fine now

im gettin a little stutter during deceleration foot off the pedal, is it possible to adjust this away or should i leave all that up to a tuner when i go to get it dynoed?

just wondering as i have to drive it for a bit before any actual tuning can take place due to the newly built engine

Many problems end up being mechanical

Watch the MAF voltage on decel and if it is spiking and then leaning out you have reversion issues

richardo -you may need to increase the scales further (to your maximum TP value)