Just got Nistune Working... Needs tons of help...

[1SIKZ31]

Well We finally got nistune working.

Heres my set up:

87 turbo ecu w/ nistune
walbro 255 pump
450cc low imp. DSM injectors

Now...
I dont know ANYTHING about nistune like you guys do, as a matter of fact firehawk is actually tuning my car for me, so please take it easy on me.

We finally got everything finished and started the car, using stock injector size as a base point. started the car, of course car ran like absolute CRAP, ran EXTREMELY rich that you had to leave throttle body open at half throttle.

So we went to injector resize, and resized to 450cc injectors, applied it and gave it another shot.
Car ran EVEN worse! Fuel pressure is steady at 38PSI.
In the ADR files, we noticed a possible error?
It says something like this:

300zx-z31-84-85.adr
300zx-z31-86.adr
300zx-z31-86-89.adr

Thats not possible though is it?
Firehawk said that 86 and 87 should be similar, and 88 and 89 are completely diffrent than the rest, but how can you have 86 and then 86-89?

We tried loading them all up, one at a time and starting the car.
Car smokes HEAVILY, runs like crap, it runs SO rich that I can get in to 5psi boost if I open the throtle body. Also... it wont rev over 1.5k rpms.

Firehawk messed around with the raw values if Im not mistaken and it ran a LITTLE better, but still so rich that getting in to boost was possible sitting still...

All of this, is done with the car just sitting, no driving it around, all were trying to figure out is to make the freaking thing run, im so frustrated!

I know I dont know much but I tried my best and need this thing back on the road.

[Matt]

Some stuff to check

- Use the 300ZX-Z31-86-89.ADR file since the other 86 file is for N/A only and only difference is fuel/timing scalers

- Make sure you are using the latest version 0.90119 since some of this stuff doesn't work properly in earlier versions

- When doing the injector resize, was the original CC matching what your stock injectors were?

Please see our FAQ Document.
Section 3 'How to I adjust for different injection size'
http://home.aanet.com.au/nistune/reg.html

Things to start changing to get it running better (this will work)

K Constant - Global fuel multiplier. Increasing/decreasing this will adjust your base Air Fuel Ratios. Make changes in small steps (like about +/- 10 at a time using the +/- keys) and you should start noticing changes. Once you get it right, the AFRs will be back on scale again

Pre-Ignition time (Injection Latency). Modify this afterwards, this needs to be modified sometimes for larger injectors because they take longer to open/close. Will mainly affect around idle

[SupSay Z]

i also had this problem at first. when you first start nistune and your injectors are at 260 make sure your constank k is at 607. if not change manually, mine was at 0. go to resize injectors and click the two boxes when you input the new size and that should take care of it. hope this helps.

alex

[Firehawk]

I think it is a problem with the injectors. I tried the computer with a stock tune in another car and it worked fine. Also, his car does not run consistantly. Sometimes it is fine, other times it is very rough.

[ByReaL]

did you changed also the void time when you resized the injectors ?

[Matt]

I've emailed chuck about the injector void time. To adjust for latency. The size of the new injectors is quite a change so this will have an effect on things

[1SIKZ31]

Ok.
Heres the deal,

We loaded up a new Fresh stock tune, and noticed the k-constant to be 607.
Now... We went to injector Re-Size and it said 260CC inthe top box, and blank in the 2nd box, we changed it to 450cc's in the bottom box.

We pushed ok, and noticed that the K-Constant went down to 350 if I remember correctly.

We started the car, and it ran like crap. Boost sitting still was possible, and I fouled a set of spark plugs in MINUTES. literally.

Now chuck messed with INDIVIDUAL raw values, and increased my timing on Nistune (ECU Timing NOT ignition timing), he messed with these individual values for about 2 hours, slowly just messing with things and changing them up little by little and he got to car to run pretty "decently".

He bumped up the lower-rpms's timing in nistune and HOLY crap I gained im not kidding 50-60% more low end torque.

The car is in "runs and drives like crap but can be driven around everyday" condition.

I cant get in to boost, if I do it'll pull to full boost at WOT (8PSI) and it feels like the car isnt going anymore, its like hitting the brakes while in to boost.

We didnt change anything else up, but we noticed that the "ecu voltage" on nistune itself is ALWAYS below 4-5 volts or less.

We connected a wideband to the cars open downpipe, and it said im running lean, which me and chuck agreed couldnt be the case since its running "extremely rich", and came to the conclusion that since im running open downpipe and the wideband o2 is at the very tip of where the exhaust exits, that its giving a bad reading.

Are we doing this right?... why isnt the car running "just like stock" whenever we load up a stock tune modded to 450's.

Do we have to change anything else?
thanks



Note: Also whenevr driving the car... whenever I get in to a "high load" situation and then push in the clutch and let it idle the engine's idle speed would go down and then the engine would turn off, Im guessing from running super rich?

[Bernardd]

Post what you have so far. The wideband will be reading lean because you are misfiring due to fouled plugs most likely. Very common beginner's mistake.

In the fuel map, in hex view, make sure all the values in the closed loop area (the values around C0 are closed loop) are zero. Leave the open loop values alone.
Make sure that the o2 feedback is set to FF.
Change the injector size from the operations dropdown. Make sure that auto tpscalers are selected. 350decimal is a good starting point for 450's.

Start the car, note the afr, change k value to keep the afr's reasonable, with a gradual trend towards 14.7. If everything is stable use the consult guages to make sure all sensors are ok.

After the car is warmed up and idling at 14.7 you can start finetuning the k value and latency by reving the car to 3 k or so and making sure the afr's stay around 14.7. It may take several adjustments of either or both of the constants to get it right. After you have that stabilized you can go for a LOW LOAD ride. DO NOT go into boost until you've verified all is well, which most likely won't be during the first ride.

I like to change the table view to afr's when tuning. I watch the maptrace to find the commanded afr and the wideband to see how close it is. You should be able to get to within .5 to what the table is commanding by only tuning the k and latency. Make sure the tp scales are corrected by the same amount as the kvalue. Datalog and post results along with the binfile used.

[Matt]

the reported ECU voltage is concerning. check all the voltage connections going into the ECU. I've emailed Chuck a pinout diagram. minimum voltage should be 10v

[1SIKZ31]

Thanks so much for the info. matt and bernard and the others, heres what we came up with so far...

we started the car, and connected to the laptop and got 4.6 volts according for nistune, so we took out a fluke77 multimeter and checked all the pin connections, they all read really weird, sometimes 1 volt, sometimes 12, sometimes even with the car off it was 1.3 volts (with ignition out)...

Anyway... we wanted to see if it was a wiring problem or a ECU Problem or what...
We took out the Nistune ECU and plugged it in to a bone stock turbo 300zx, turned the key to "on" and the voltage was the same! weird... firehawk took out the ecu and opened it up (still connected to the car though) and we took the fluke and checked for continuity between all the solder contacts, and checked voltage at all the nistune contacts (there were about 20 of them) and all came out good.

ECU back in my car... we started it and decided to "start over"... base tune changed to 450cc injectors and firehawk adjusted injector latency, INSTANT results!

Car ran almost seamlessly during "daily driving" conditions, but whenever we would get in to boost, wether it was Partial throttle or full throttle, the car would "pop"... its like a GIANT misfire over and over again... it sounded like it was detonation but at the same time sounds like either the engine is getting to much fuel or to little fuel?

We kept messing withthe K-Constant and put the car continously under 1-4 second 3rd gear low rpms WOT pulls adjusting things slowly, we would lean it out and notice the car would get better... actually one time it ran PERFECT at WOT, pulled HARD (6psi boost) and ran SMOOTH, but most of the time it doesnt go anywhere under boost and just sounds like MULTIPLE one after another ignition misfires or what not...
Anyway ANY advice would be appreciated...
Were installaling a wideband 02 bung here shortly to see AFR's since putting the wideband right at the end of the downpipe is giving what seems to be bad result.s..

Bernard... we changed the plugs, they arent fouled n e more, thanks!
(but still getting wrong wideband numbers)

[GZ@hybridka]

Test these things,

Battery voltage with engine off (DC,measure at posts)
Battery voltage (DC) with engine running, idle
Battery voltage (AC) with engine running, idle

Then note/compare to measurement at ECU terminals.

Do you notice any gauge panel or other electrical anomalies?

This data would help to diagnose what sounds like an alternator/charging system problem. Your coil cannot charge properly without appropriate source voltage.

[Matt]

See if you can also clean the ECU contact pins. Seems to be some connectivity issues with that ECU to the loom

[Matt]

Okay the updated firmware rev for 1986/1987 ECUs should fix up your battery and fuel temp reporting issues

However it doesn't resolve the problems you are having right now. As in the other thread, are you able to post a log with the AFRs as you exercise the rev ranges

Also what K constant and Latency (void time) are you using? Any other parameters changed?