Nistune Forums

hi, i got my car tuned, while on the dyno it popped a head gasket. when i fixed it and got it going again it was running on 5 cylinders. number 5 was missing.
i beleive it was running on 5 cylinders when it was tuned.
now its on 6 again, at idle its on 12 to 11 a/f. as i accelerate it leans to 17 when it gets on boost it goes to 12.

any way i can try fix it with the nistune software and a wide band. i have never tuned before but im not taking it back to the guy who tuned it, its a 3 hour drive.
im over paying people to tune it and getting no results
it has 440cc injectors and a z32 AFM.

ive attached the tune if someone can look at it and help tell me where to start.
would the calibrations for the air flow meter and injectors be out?

Read the tuning guides on our website as a start. Adjusting K constant will be the first thing to pull the fueling back to where it should be.

Should not have have been tuned on 5 cylinders!!

i recorded a log

got it to right temp, then just drove around the block.

Well you can see from the AFRs in the tracer you are rich down the bottom end (11:1 around idle) and then it goes lean when going on boost before hitting okay AFRs top end

However this doesn't seem the match the injection time (which is about 6ms going on boost and 7.3ms at 4000rpm)

Is the Z32 MAF confirmed genuine? Where did you source it from? Any other possible vacuum leaks. I dont understand why its going lean in the middle there

ok when i get a chance ill check for leaks
why is it so rich at idle, i thought the ecu and 02 sensor automatically trim it to 14.7

and where it goes real lean is a massive flat spot, like the revs just stop at 2000 to just a crawl till it gets to 3000. then it seems fine.

The ECU uses the O2 sensor to adjust an overall trim (entire map) not just one area. From memory I think O2 feedback temp was set to maximum disabling trimmings

had a quick play with it.
i changed the fuel map to another one i had (might look familiar matt)
and tweaked the latency and the k constant, seems a bit better. doesnt seem to lean out now.
still goes a bit too rich and doesnt richen up early enough (boost starts around 2500rpm) but i guess thats just in tuning

but it seems all the problems are tune related.

at idle in drive with foot on brake afrs are ok but when its in nutral or park it goes rich? that seems weird

More injection time than before. Have no AFRs so cannot tell much more than this but looks better than the first log

does anyone know what table the ecu access between drive and neutral.

car stationary in drive afrs are good but as soon as its in neutral they go rich

There is no mixture adjustment (I know of) when in neutral

Below screenshot shows in log that pressing neutral switch on/off does not change timing (yellow) or injection (purple)